Home » Mobile communications » Installing, configuring and using BitTorrent Sync. Temporary access to a folder in BitTorrent Sync. Installing HTC Sync Manager on a Windows computer

Installing, configuring and using BitTorrent Sync. Temporary access to a folder in BitTorrent Sync. Installing HTC Sync Manager on a Windows computer

BitTorrent Sync is a torrent client that does not require torrent trackers. It is also a tool for synchronizing files between devices: personal computers, laptops, tablets, etc. When synchronizing, data is transmitted via the P2P protocol, bypassing remote server, i.e. synchronization and data transfer are carried out between devices, ensuring that the transmitted data does not fall into the wrong hands. The fact that data exchange is secure is secured by the use of encryption.

Operating principle

Using the client, you can provide access to your files to your friends, family, work colleagues, or synchronize your files between different devices. Each folder that is shared receives a secret key. Share this key with people you want to share your files with, or use it yourself on your other devices to sync files. It is enough to install the client on another device, enter the secret key, and after a while, your files are synchronized.

Attention! Synchronization and exchange of files between devices is possible only if the devices are turned on and connected to the Internet. They will find each other themselves using the mechanisms of the P2P protocol.

BitTorrent Sync is ideal for sharing photos and home videos with family and friends around the world. It is ideal for group, distributed work between people.

If you saved the installer to disk, then go to the download folder and run the BTSync.exe file.

It is advisable not to uncheck these boxes. The first checkbox will add an exception for this application to Windows Firewall, the second will make it so that the application will launch when the system starts, and accordingly, the files will be constantly synchronized between all devices.

Click Install !

Initial setup

Installation is instant, right? This is the window:

Allows, or create new folder to sync files between devices, or sync a folder with files on this device with a folder on another device. Those. choose:

Standard Setup - to share your folder.
I have a secret — to synchronize files from another device on the network. In this case, in the field below, under the item I have a secret insert the secret key that you received on another device when moving by Standard Setup , or the key that you received via soap/ Your option from a comrade in arms who decided to share his precious files with you.

Standard Setup

Next or Skip . I'll press Next — I want to share my files with the world!

Select the folder with files to share/synchronize:

Please note that files in the selected folder will not be deleted. You can immediately choose the path to the folder with home photos. However, you should take into account the fact that synchronization implies the ability to change and delete files on connected devices. I will discuss the aspects of access rights and file protection from deletion below.

To copy, press the button Copy .

Click Next :

Next Skip Tour .

I have a secret

Now consider the option in which we already have a secret key and want to connect to private network exchange files or synchronize files with another device that already has the BitTorrent Sync client installed.

I paste the code:

Select the directory into which the files will be downloaded:

Click Next :

This is an introductory tour, click here Next and familiarize yourself with the capabilities and functions of the program. I'll press Skip Tour .

Let there be a window! then a window will open

On the tab Shared Folders synchronized paths are listed. You can also create or connect new folders, manage access rights, view the secret keys of folders for connecting them on other devices, and manage their fine settings. I will describe these operations below.

On the tab Devices connected devices are listed. This is simply wonderful!

On the tab Transfers you can see what is distributed where, and what is loaded where. And also the speed of sending and receiving.

On the tab History you can track current events. Some radish deleted or moved my “Installing, Configuring and Using BitTorrent Sync.docx” file. 🙂

On the tab Preferences you can configure client settings.

For example Devicename is the name of your device. It will appear on the tab Devices other clients who either provided you with access to files, or to whom you provided access. Modify this parameter so that your friends immediately understand that it is you. I think it’s already clear what the other parameters mean. In 99% of cases they do not require modification.

By clicking on the button Advanced… can you take a look at fine settings. Nothing interesting.

Folder management

Let's go to the tab Shared Folders and click on the path line with the right mouse button. Here it is - the menu!

Here's the point:

Open folder – will open a path in Explorer
Copy secret – will place the same secret key on the clipboard, which can be inserted into soap and sent to a beloved relative. Let him look at photos from his grandmother’s birthday.
Show folder preferences – and this item will open a window with all available settings for the shared pack. Let's see what's there:

I will not explain what each point means, I will only focus on the point DeletedfilestoSynctrash, which already has a check mark by default. This means that if your relative deletes the photos of your beloved grandmother, they will not be deleted, but will be moved to a special, hidden folder, which is located in the shared directory. You may not see it in Windows Explorer if the “do not display” option is set in the system. hidden files and folders." Total Commander will show this folder without problems during basic setup:

Advanced settings window, in addition to the tab General , has a tab Advanced . There are so many interesting and useful things there!!! There seem to be a few exclamation marks, right?

That's how it is! There are so many different and interesting secret keys!

Secret is a key that gives its owners access in read and write mode
Read only secret is a key that gives its owners access only and exclusively in read mode. Exactly this key is worth sending to relatives so that they don't accidentally delete anything. When synchronizing and group interaction, you should use the key above. Please note that this key protects files from changes, i.e. The grandson definitely won’t finish drawing a mustache on his grandmother’s photos. 🙂
One- time secret – You can provide the owners of this key with access for a period of 24 hours. After this time, the key will be canceled and its owner will not be able to synchronize his files with yours.

It is worth clearly understanding the fact that BitTorrent Sync is a program that synchronizes files. If you have given access to your files, they are copied to the device of the owner of the secret key, which gives him this access. Deleting files on your part does not guarantee that copies of these files will be deleted from devices that had access to your device.

Access in read-only mode ensures that the files you have are not modified. If you have access to files in read-only mode, all your changes to these files will be reset, and the changed file will be synchronized again.

A 24-hour key only guarantees that the user who has this key will be able to access your files during the validity period of this key, essentially copying your files to themselves. After the expiration date, the user will lose the ability to synchronize files between your device and his, but will not lose the files that have already been received.

Adding a new folder for sharing and synchronization

Let's go to the tab Shared Folders and click on the Add button at the bottom of the window, thereby opening the dialog for adding a new synchronization node.

Select the path and generate the key using the Generate button:

I decided to share pron. The folder has been added to the list of paths. The secret key has been sent to everyone interested parties, indexing of the folder and all the wealth it contains will soon be completed. I gave you the basic material. I need to go eat, I'm tired!

Acknowledgments

BitTorrent for a wonderful tool!

Special thanks to the captain of the ISS, Chris Hadfield, for his delightful and poignant performance of the song “Space Oddity”, it was she who set the tone and helped to finish this topic to the end.

Do you have a G-SYNC capable monitor and an NVIDIA graphics card? Let's look at what G-SYNC is, how to enable it and configure it correctly in order to fully use the potential and capabilities of this technology. Keep in mind that just turning it on isn't everything.

Every gamer knows what vertical synchronization (V-Sync) is. This function synchronizes image frames in such a way as to eliminate screen tearing. If you disable vertical synchronization on a regular monitor, you will decrease the input lag (latency) and you will notice that the game will respond better to your commands, but thus the frames will not be properly synchronized and it will end up with screen tearing.

V-Sync eliminates screen tearing, but at the same time causes an increase in the delay of the image output relative to the controls, so that the game becomes less comfortable. Every time you move the mouse, it appears that the movement effect occurs with a slight delay. And here the G-SYNC function comes to the rescue, which allows you to eliminate both of these shortcomings.

What is G-SYNC?

Quite expensive, but effective solution for video cards NVIDIA GeForce is the use of G-SYNC technology, which eliminates screen tearing without the use of additional delay (input lag). But to implement it you need a monitor that includes the G-SYNC module. The module adjusts the screen refresh rate to the number of frames per second, so there is no additional delay and the effect of screen tearing is eliminated.

Many users, after purchasing such a monitor, only turn on NVIDIA support G-SYNC in panel settings NVIDIA management with the conviction that this is all that must be done. Theoretically yes, because G-SYNC will work, but if you want to fully maximize the use of this technology, then you need to enable a number of additional functions related to the appropriate setting of classic V-sync and limiting the FPS in games to a number of frames less than the maximum refresh rate monitor. Why? You will learn all this from the following recommendations.

Enabling G-SYNC in the NVIDIA Control Panel

Let's start with the simplest basic solution, that is, from the moment you turn on the G-SYNC module. This can be done using the NVIDIA Control Panel. Click right click mouse on the desktop and select NVIDIA Control Panel.

Then go to the Display tab - G-SYNC Setup. Here you can enable the technology using the “Enable G-SYNC” field. Tag it.

Then you can specify whether it will only work in full screen mode, or can also activate in games running in windowed mode or a full-screen window (without borders).

If you select the "Enable G-SYNC for full screen mode", then the function will only work in games that have set mode full screen (this option can be changed in the settings of specific games). Games in windowed mode or full screen will not use this technology.

If you want windowed games to also use G-SYNC technology, then enable the “Enable G-SYNC for windowed and full screen mode” option. When this option is selected, the function intercepts the currently active window and overlays its action on it, enabling it to support modified screen refresh. You may need to restart your computer to activate this option.

How to check that this technology is enabled. To do this, open the Display menu at the top of the window and check the “G-SYNC Indicator” field in it. This will inform you that G-SYNC is enabled when you launch the game.

Then go to the "Manage 3D Settings" tab in side menu. In the "Global settings" section ( General settings) Find the “Preferred refresh rate” field.

Set this to "Highest available". Some games may impose their own refresh rate, which may result in G-SYNC not being fully utilized. Thanks to this parameter, all game settings will be ignored and the ability to use the maximum monitor refresh rate will always be enabled, which in devices with G-SYNC is most often 144Hz.

In general, this is the basic setup you need to do to enable G-SYNC. But, if you want to fully use the potential of your equipment, you should read the following instructions.

What should I do with V-SYNC if I have G-SYNC? Leave it on or turn it off?

This is the most common dilemma of G-SYNC monitor owners. It is generally accepted that this technology completely replaces the classic V-SYNC, which can be completely disabled in the NVIDIA Control Panel or simply ignored.

First you need to understand the difference between them. The task of both functions is theoretically the same - to overcome the effect of screen tearing. But the method of action is significantly different.

V-SYNC synchronizes frames to match the monitor's constant refresh rate. Consequently, the function acts as an intermediary, capturing the picture and therefore the display frame so as to adapt them to a constant frame rate, thereby preventing image tearing. As a result, this can lead to input lag (delay), because V-SYNC must first “capture and organize” the image, and only then display it on the screen.

G-SYNC works exactly the opposite. It adjusts not the image, but the monitor refresh rate to the number of frames displayed on the screen. Everything is done in hardware using the G-SYNC module built into the monitor, so there is no additional delay in displaying the image, as is the case with vertical synchronization. This is its main advantage.

The whole problem is that G-SYNC only works well when the FPS is in the supported refresh rate range. This range covers frequencies from 30 Hz to the maximum value the monitor supports (60Hz or 144Hz). That is, this technology works to its full potential when FPS does not fall below 30 and does not exceed 60 or 144 frames per second, depending on the maximum supported refresh rate. The infographic below, created by BlurBusters, looks really good.

What happens if the fps goes outside this range? G-SYNC will not be able to adjust the screen update, so anything outside the range will not work. You will find exactly the same problems as on a regular monitor without G-SYNC and classic vertical sync will work. If it is turned off, screen tearing will occur. If it is turned on, you will not see the gap effect, but an iput lag (delay) will appear.

Therefore, it is in your best interest to stay within the G-SYNC refresh range, which is a minimum of 30Hz and a maximum of whatever the monitor maxes out (144Hz is most common, but there are 60Hz displays as well). How to do this? Using appropriate vertical synchronization parameters, as well as by limiting the maximum number of FPS.

What, then, is the conclusion from this? In a situation where the number of frames per second drops below 30 FPS, you need to leave vertical sync still enabled. These are rare cases, but if it does happen, V-SYNC ensures that there will be no tearing effect. If the upper limit is exceeded, then everything is simple - you need to limit maximum quantity frames per second, so as not to approach the upper limit, when crossed, V-SYNC is turned on, thereby ensuring continuous operation of G-SYNC.

Therefore, if you have a 144 Hz monitor, you need to enable the FPS cap at 142 to avoid going too close to the upper limit. If the monitor is 60 Hz, set the limit to 58. Even if the computer is able to make more FPS, it will not do this. Then V-SYNC will not turn on and only G-SYNC will be active.

Enabling Vsync in NVIDIA Settings

Open the NVIDIA Control Panel and go to the “Manage 3D Settings” tab. In the Global Setting section, find the Vertical Sync option and set the option to “On”.

Thanks to this, vertical sync will always be ready to turn on if FPS drops below 30 FPS, and the monitor with G-SYNC technology I couldn't handle it.

Limit FPS to less than maximum screen refresh rate

The best way to limit frames per second is to use RTSS (RivaTuner Statistics Server) program. Undoubtedly, the best solution is to use the limiter built into the game, but not everyone has it.

Download and run the program, then in the list of games on the left side, check the Global field. Here you can set a common limiter for all applications. WITH right side Find the "Framerate limit" field. Set the limit here for 144Hz monitors - 142 FPS, respectively, for 60Hz devices -58 FPS.

When the limit is set, there will be no delay in activating classic vertical synchronization and playing will become much more comfortable.

Cloud technologies have recently taken high positions among both professional webmasters and ordinary people far from the field of high technology.

There are a huge variety of services that allow you to perform tasks of different plans in nodes located on different continents. Be it storage data in the cloud or brute force hashes, there are always ready-made services that will help you with this. Today I'll look at a relatively new one protocol-based type of data storageBitTorrent.

I'll start with where they always start. As you know, the main services for storing user data are DropBox, Box, Google Drive, Yandex Drive and the like.

What is their advantage?

These services work exactly on cloud technologies. All your data is scattered on different servers that are managed by a specific application. You can share a link to your file with friends and acquaintances and this is quite convenient. Since there are many users on these sites, measures are being taken to reduce traffic. Let's say you download a file not at maximum speed, but at the speed that your data storage service has determined for you.

What are the alternatives?

You all know very well what torrent trackers are. These are sites and applications for exchanging information. For example, the most famous torrent trackers Russian audience is RuTracker. You download a torrent file that contains information about the files contained in the distribution. Next, the torrent client program processes the information from this torrent file and uses a hash unique for this distribution to connect to the torrent tracker, asking it for information about who is on at the moment has the files or parts of files we need from the distribution. The download begins. I like the bit-torrent protocol; this is perhaps one of those technologies that will develop in the near future. This is how it happens, online players appear to play video and audio files, which are assembled from pieces received from different users who have these pieces. The advantage of this protocol is decoupling from a specific server, which allows, if there is at least one peer, to collect a file. Besides simple players Online broadcasts based on this protocol are organized.

What is BitTorrent Sync?

If you read the above, you probably thought why not use the BitTorrent protocol to simply store your files, with some kind of protection from other users. That’s right, this is exactly what we’ll be talking about.

BitTorrent Sync program is a kind of file manager, let's call it that, which sends our file or folder to different clients using encryption.

A little about how to use BitTorrent Sync.

The program is at the beta testing stage, but is already actively gaining people's trust.

The installed program looks something like this:

We have five tabs. Let's look at each one. Let's start with Shared Folders.

As it becomes clear from the title, this is the tab in which our sharing folders are displayed. When adding a new folder, we need to specify the path to it and generate a secret key with which we can give access to this folder to other users.

Now if we click on the newly added directory, a window similar to this will open:

The first checkbox is used to allow the use of a relay server as needed.

“Use tracker server” - used to use the tracker.

“Search lan” - apparently used to search for local peers.

“Search DHT Network” - this option is disabled by default, since it is unlikely that other people on the network have folders identical to yours.

“Delete files to Sync trash” - apparently serves to delete files into Sync’s own trash.

“Use predefined hosts” - used to specify own addresses servers, after checking the box, the Add button will be available, but you don’t need to worry about it.

The Advanced tab of this window contains secret keys. In addition to full access to files, you can give read-only access, which is very convenient. You can also generate a random key that is valid only for 24 hours.

The “Preferences” tab is a tab with the main settings of the program.

Device name – the name of the device that will be displayed on other computers.

Show notifications for complete downloads – notify us when file synchronization is successfully completed.

Start BitTorrent Sync when Windows starts – start the program immediately after start operating system.

Listening port – the port on which BitTorrent Sync runs.

Use NAT UpnP port mapping – used to bypass some NAT restrictions.

Check for updates automatically – whether to check for new versions of the program.

And below you can set the maximum speed for downloading and distributing content.

Let’s say you shared a folder by adding it on the “Shared Folders” tab. Double-click on it and see the secret key, or generate a new one. If you're ready, move on.

If you are wondering " How to share a folder in BitTorrent Sync?" or " How can I access my folder?“I think you are on the right track. A little bit left (=

Let's assume you are sitting at another computer, let's try to download files from our main one.

To do this, go to the “Shared Folders” tab and click Add. Enter the secret key that you generated on the first computer. And the location can be anything.

Ready. Yes, it's that simple.

If everything is correct, then the name of the main computer will appear on the “Devices” tab. While I was writing this, file synchronization has already taken place and it looks like this:

Well, a little about the “Transfers” tab: these are active transfers, for example, if you are currently transferring a file, it will be displayed here, and the speed and other data will also be displayed.

I hope this is a little clearer, thanks for reading.

BitTorrent Sync is the ability to transfer files securely and encrypted between your (and only your) devices using the BitTorrent protocol. There will be no need for newfangled ones clouds, into which people upload encrypted backups, since it is not clear who can do it on the side clouds rummage through your files.

btsync works on most modern operating systems:

Mac OS X Snow Leopard or later.
Windows XP SP3 or later.
Linux with kernel 2.6.16 (glibc 2.4) or later.
FreeBSD 8.4, 9.1 or later.
Android 2.2 or later.
iOS 5.0 or later.

For many, it is common to associate BitTorrent with a bunch of people downloading pirated movies together, thanks to torrent trackers. But in the case of btsync, this is not the case! To sync your files between your devices, you will need to generate a symbolic secret key. BitTorrent Sync uses /dev/random on Mac and Linux and the Crypto API on Windows to generate your random, Base32-based, character-based secret key. All traffic during synchronization will be encrypted with AES.

If synchronization will not be carried out in local network, and over the Internet, then UDP, NAT traversal and UPnP can be used to pass encrypted traffic through routers. But in any case, files are transferred over encrypted connections only between your devices that know the secret key.

To solve the problem of searching for your devices on the network, the following solutions exist:

Local peer discovery. If all your devices are on the local network, then a broadcast packet is sent to search for them. All devices with a single secret respond to such a packet and thereby begin interaction.
Peer exchange (PEX). Your devices help each other by providing addresses they know.
Known Hosts. For a local network with permanent IP addresses, you can manually specify the addresses where your devices live.
DHT (Distributed Hash Table). If you allow, a distributed hash table will be used to search for all your devices that know SHA1 (secret key).
BitTorrent tracker. BitTorrent Sync may, with your permission, use a tracker to make it easier for your devices to find each other. The tracker also acts as a STUN server and helps devices establish a direct connection that may be behind NAT.

Cons of btsync.

btsync is free program closed source.

BitTorrent Inc does not have access to encrypted files, does not host the files and does not control the process in any way, but collects anonymous statistics about:

Architecture.
Number of files.
Number of folders.
Unique ID.
Program options.

and in certain situations sends it to the BitTorrent Inc servers - see details in. For some, these disadvantages may outweigh the advantages of the program and you should know about them in advance.

Installation into the system.

The fact is that the btsync binary, downloaded from the page labs.bittorrent.com/experiments/sync.html, when launched, will scatter and create the files it needs along the paths built into it.

To do everything beautifully in Ubuntu and solve it right away all questions with access rights to required folders and organize the launch of btsync after the reboot, you can use the BitTorrent Sync PPA repository - ppa:tuxpoldo/btsync and add it to the system sudo apt-add-repository ppa:tuxpoldo/btsync

I took a different route by creating my own btsync deb package, which allowed me to independently control all the stages.

Download the btsync.tar.gz archive, which contains everything you need to create your own deb package.
Unpack the archive.
New versions of the btsync binary downloaded from its native site should be placed in bittorrentsync/usr/local/bin/.
In the bittorrentsync/DEBIAN/control file, you should change the Version and Architecture fields, depending on what you downloaded from the official website.
It is assumed and written in the scripts that a user and group will be created with the name btsync.
You can create a configuration file in advance with the necessary settings and save it in bittorrentsync/etc/btsync/sync.conf. The parameters will be described below.
Run create-bittorrentsync and get a deb package that can be installed on Ubuntu systems.

Options used in btsync.

The configuration file format must be in JSON. The following parameters can be applied in the configuration file:

What are the secret keys in btsync.

WITH full access(Full access) - given master the key allows all devices full two-way access during synchronization. In the console use btsync --generate-secret
Read only- this key is generated based on the master key using btsync --get-ro-secret MASTER KEY. Used only in one-way synchronizations.
One-time- this secret key can be created based on the Full access master key or the Read only key. A One-time key is limited to 24 hours after it is created, after which it will not work.

Ignoring files.

If you have selected folders and files for synchronization, but you would like to exclude some files from synchronization operations, then the .SyncIgnore file in UTF-8 encoding will help you.

File masks are supported - * and ?

File versioning.

BitTorrent Sync supports file versioning since its release 1.1.16. By default, old files are stored for 30 days in the .SyncArchive/ subfolder. The storage period can be configured via the sync_trash_ttl parameter. Older versions of files are marked with an additional number in the file name, and the higher the number, the more “later” the version of that file is.

Using btsync using the web interface.

For the web interface to work you need:
1) absence in the configuration file of the shared_folders block. You will be able to share folders in the web interface.
2) availability in the webui block configuration file.
Example
"webui" :
{
"listen" "0.0.0.0:8888",
"login" "admin",
"password" "pa$$1admin2very3Strong!"
}

Using the web interface it is not at all difficult to share a folder. Use the Add Folder button first and click the Generate button once and only once and save your secret key. Specify the Path to the folder that will participate in synchronization.

On your other devices, no longer click the Generate button, but simply add folders and indicate the secret key you have already received.

Using btsync without the web interface.

Administrators may want to set up synchronization of multiple servers, without hanging an extra port with the web interface, although it is password protected.

I needed to set up synchronization among 3 servers, where each server would put its backups in a specific folder, and files from it would be synchronized using btsync to the other two servers, which created the necessary redundancy.

The web interface will turn itself off if
1) present in the configuration file there is a block shared_folders.
2) absence webui block or its listen parameter.

Using the btsync --generate-secret command, the secret key AVE43EXY2TMKKXZISGEJ7S7NSGGPHRJBR was obtained, which was specified in the secret parameter of the shared_folders block. Since synchronization will take place within the walls of the local network, technologies such as tracker, DHT, and relay server are disabled. And since we are talking about a local network, all IP addresses of servers are indicated in the known_hosts block. The user from whom btsync will run has permission to write to the /var/dump_backup/, /var/run/btsync/ and /usr/local/lib/btsync/ directories.

In my case, the conf /etc/btsync/sync.conf took the form:
{
"device_name": "node1",
"listening_port" : 8889,
"storage_path" : "/usr/local/lib/btsync/",
"pid_file" : "/var/run/btsync/btsync.pid",
"check_for_updates" : false,
"use_upnp" : false,
"disk_low_priority" : true,
"lan_encrypt_data" : true,
"lan_use_tcp" : true,
"max_file_size_diff_for_patching" : 50,
"folder_rescan_interval" : 60,
"download_limit" : 0,
"upload_limit" : 0,
"shared_folders" :
[
{
"secret" : "AVE43EXY2TMKKXZISGEJ7S7NSGGPHRJBR",
"dir" : "/var/dump_backup/",
"use_relay_server" : false,
"use_tracker" : false,
"use_dht" : false,
"search_lan" : false,
"use_sync_trash" : false,
"known_hosts" :
[
"10.0.1.11:8889",
"10.0.1.22:8889",
"10.0.1.33:8889"
]
}
]
}

This config was replicated to other servers and only the device_name parameter was corrected, which must be unique within your synchronization system. Restart the btsync service on all servers - sudo /etc/init.d/btsync restart and now any file that ends up in the /var/dump_backup/ directory will appear on all other servers in their local /var/dump_backup/ directories.

FAQ btsync.

Can any other BitTorrent users see my files?
No. Although BitTorrent Sync is based on the BitTorrent protocol, BUT all traffic is encrypted private keys, obtained based on your master secret key. Your files can only be seen and downloaded by those people to whom you give your secret key.
What is this secret key and how does it work?
A secret string of characters is automatically generated based on your request and ensures its uniqueness. Since each secret key is 20 characters long, it is unlikely that the same secret key will be created simultaneously in two different places. If you are paranoid about security, then it is possible to create new secret keys and replace current ones with more than 40 characters in the secret. Don’t forget to replace it after generating a new key for the folder on all your devices old key new.
How quickly will synchronization begin when changes occur?
If a file ends up in a shared folder, it will be synchronized immediately after it is saved or closed. Since different operating systems have different nuances associated with monitoring file operations, an additional mechanism has been introduced to force folder scanning at a certain time interval. The folder_rescan_interval parameter is responsible for this.
What are the .SyncID, .SyncIgnore, .SyncPart, .SyncTemp and .!Sync files and .SyncTrash/.SyncArchive folders?
When you share a folder, some service files and folders are created in it:
- .SyncID - the file contains the unique, internal ID of the folder. If you delete a file or manually change it, BitTorrent Sync may not recognize the folder and may not synchronize it.
- .SyncIgnore - a file in which you can specify files to be excluded from the synchronization process. Specifying using masks * and? is supported.
- .SyncTrash - (before v1.1.40) BitTorrent Sync does not delete your files by default. This folder contained files that were deleted on your other device.
- .SyncArchive - (v1.1.40 onwards) is the new name for .SyncTrash, where deleted files are stored in the new versioned style.
- .!Sync - BitTorrent Sync saves temporary files during transfer with a postfic.!Sync. After receiving the entire file, the postfix is removed. For example file.mp3 upon receipt will be visible as file.mp3.!Sync and after full download it will be file.mp3.
- .SyncPart - this extension indicates that the file is currently being updated by patching changed chunks.

What happens if several people make changes to the same file?
When a file is changed on one device, it is recreated on other devices. The latest version of the file will be saved.
What happens if you delete a file from a shared folder?
After deleting the file, other devices will synchronize and also remove the file from their directories allocated for synchronization by this key. If use_sync_trash = true, then the files will be moved to the .SyncArchive/ subdirectory inside the dir variable directory. If use_sync_trash = false, then depending on the operating system, the files will be erased forever or will end up in the system Trash.
sync_trash_ttl will determine the number of days that deleted files have been in .SyncArchive/.
What will happen if at the same time in directories with different devices will a file with the same name appear?
A person is always right, so BitTorrent Sync synchronizes everything and whoever was added last will overwrite competitors, even if they are more relevant.
What happens if you remove a folder from sharing?
All files will remain in place. Undownloaded files with the .!sync extension will be deleted.
What is sent to BitTorrent Inc servers and when?
Only when you use tracker (use_tracker = true), relay (use_relay_server = true) and update check (check_for_updates = true) is it possible to send anonymous usage statistics.
Dispatched:
- Architecture.
- Number of files.
- Number of folders.
- Unique ID.
- Program options.
How to control the frequency of folder polling and synchronization?
Synchronization is done in real time. In addition to the real-time algorithm, shared folders are scanned once every folder_rescan_interval.
How are devices synchronized when they are turned off?
No way. BitTorrent Sync - this is not a cloud solution like SkyDrive, DropBox, GDrive. You synchronize only between your devices and they must all be turned on, or at least in pairs.
How to synchronize the internal HDD and external USB drive?
No way. BitTorrent Sync does not synchronize local folders within a computer, but rather synchronizes folders between network devices.
Can I use synchronization only on a local network? Without any connection to the Internet!
Yes, you can. Disable:
- Relay - use_relay_server = false
- Tracker - use_tracker = false
- DHT - use_dht = false
Synchronization will occur only within the local network.
What are the limits on file size or number of transfers?
None. It all depends only on the capabilities of your operating system and the availability free space on your disks. RAM is used at the rate of 1 file = 400 bytes. To monitor 1 million BitTorrent Sync files, you will need ~400 MB of RAM.
When a file has changed, does BitTorrent Sync retransmit the entire file or just the changes?
Files smaller than 4 MB are transferred entirely. Large files are divided into 4 megabyte chunks and only modified chunks are transferred.
Can I use BitTorrent Sync in MS Windows XP?
You need 32-bit MS Windows XP Service Pack 3. 64-bit MS Windows XP Service Pack 3 is not supported.
Is there a console (CLI) version of BitTorrent Sync for MS Windows?
No. CLI for Linux only.
Is there WebUI for MS Windows?
WebUI for Linux only.

Comparison of btsync with others.

BTSync vs Rsync.

General:
Rsync ( R emote Sync chronization) helps with safe transfer between network devices.

Rsync can using an algorithm rolling checksum effectively submit changes to file, if there is a different version of this file on the opposite side. You should know that you have to pay for this with higher CPU load, although backups using Rsync are done during low load hours and processors have become so powerful that this “minus” can be ignored. That is, Rsync and BTSync, each in their own way, are able to transfer data securely and transfer changes (deltas) of huge files when there is an old copy of the file at the destination.

Differences:
Rsync “connects” only 2 devices at a time and you can synchronize two-way: A with B and B with A. Typically, Rsync is used in schemes when devices (servers, desktops) copy their backups to a single backup server.

The advantage of Rsync versus BTSync is better information about the progress of synchronization. BTSync writes sparingly in his magazine about what he is doing at the moment.

Rsync is free software, but BTSync is not, and that's a minus.

BTSync vs Zsync.

General:
Zsync was created with Rsync in mind in an attempt to create a tool that would effectively solve the problem transferring only changes to huge files over the network, type ISO images operating systems and so that all the load is on the client side, not the server. To solve its problems, BTSync relies on chunks, and Zsync uses the following scheme. Whenever a change occurs to a large file, you need to call zsyncmake to create an index file, which should be located next to the file for which it was created. If the download is the first time, then zsync will automatically download the entire file and it will be similar to downloading the file using wget. But if the file is downloaded again, zsync will download the index file, evaluate the changes between the local and remote file, and download only the changed data blocks.

Differences:
Zsync is synchronization only in one direction and only between two sides! The client unloads the server by downloading only deltas. Zsync is very necessary on the server side - an http server that allows downloading individual parts of a file from using Range. BTSync is multiple synchronization in both directions among all participants.

Zsync is effective for single files of huge sizes that change slightly from time to time. BTSync is much more versatile in this matter. It can transfer small files entirely, and large files by transferring only changes.

Should you or shouldn't you use BTSync? Everyone must decide this question for themselves. The utility is closed - that's a fact! If she is “calmed down”, she will not send anonymous statistics to her authors if this makes someone nervous. Otherwise, it’s just an amazing synchronization mechanism in some unified field controlled only by you. No intermediaries, no clouds, no payment.

In this article we will look at how to create a backup copy of your files and maintain it in current state, as well as how to synchronize files between several computers using one of best programs FreeFileSync.

1. Why do you need backup?

Backing up your files, such as personal documents, photos and videos, will protect them from loss due to accidental deletion, operating system failure, viruses or damage hard drive.

Remember! If you don't back up your files, sooner or later you will lose them!

Another purpose backup There may be synchronization of your files between several computers. For example, you may work with the same files at home and at work, and you want files on your home and work computer to be updated as they are changed, created, or deleted.

Also, regularly backing up your files will make it much easier to restore your computer in the event of a failure. All you need to do is restore the image of the operating system, and all the files are already securely stored in a backup copy and you won’t have to spend a lot of time and effort restoring them.

2. Installing the FreeFileSync program

You can download the FreeFileSync program in the “” section.

During installation, you can select the “Local” or “Portable” version, which can be carried on a flash drive if, for example, you cannot install “Local” on your work PC.

After installation, two shortcuts are created: “FreeFileSync” is the main program and “RealTimeSync” is a utility for real-time synchronization.

3. Where is the best place to store backups?

Before we begin describing the FreeFileSync program, I want to say a little about where it is better to store backups.

The most reliable and convenient storage will be backup copies on an external hard drive.

An external drive can also be used for storage. Not only will you save your valuable documents, photos and videos, but you will also be able to quickly restore the system in the event of a failure.

The disadvantages of storing backups on a flash drive are that its capacity is very limited, the flash drive is easy to lose, and it can often require a lot of space to transfer files. In addition, flash drives are highly susceptible to failures and virus infection.

CD/DVD discs are also unreliable media, as they are susceptible to damage and, even if they just lie in place, become unreadable over time. In addition, it is problematic to regularly update files on disks.

You can store a backup copy of your files on another hard drive on your computer. But if there is a power failure, then everything can fail hard drives. Therefore this is also not recommended.

It is unacceptable to store a backup copy on another partition of the same hard drive, since if the drive fails, the backup copy will also be lost.

In general, don’t skimp and buy an external hard drive, connected via USB (preferably USB 3), via a local network (Ethernet) or store a backup copy on another computer or laptop.

If your files are very valuable and their loss would cause unacceptable damage, then store the backup copy in another location or on a server on the Internet ( cloud storage). This way, in the event of a fire or other natural disaster, your data will remain intact.

It is better to store important confidential data in encrypted form using a password, so that theft or loss of the media does not lead to disclosure or illegal use of confidential information.

The main condition for the safety of files is the constant availability of their copies. As soon as one of the copies is lost, restore it as quickly as possible.

4. Backup folders

The first backup can be created by simply copying file folders to an external drive, network folder, or other selected media. But it is better to immediately use the FreeFileSync program, as it creates its own database to track file changes.

4.1. Selecting folders for backup

Open the program, add folders with your files in the left pane, and in the right pane select the folders in which you want to save backups.

To add another pair of folders, use the plus sign “+”; to search for a folder in Explorer, use the “Browse” button. You can also enter folder paths in whole or in part manually, copy and paste paths and folder names into the required fields. If the folder you want to backup to does not already exist, it will be created the first time you create a backup.

For example, I created a “Backup” folder on the disk of my second home computer “HOME-2” and opened access to it over the network for reading and writing. This is where backup copies of my files are stored.

Choose the most suitable for backup important files. It is possible to make backup copies of folders with movies and music that can always be downloaded from the Internet, but if they take up a large amount of space, this is usually not advisable.

4.2. Selecting a backup mode

Select the backup mode "Mirror" and click "OK".

Make sure the Synchronize button is set to Mirror mode.

In this mode, when backing up, folders on the right will be brought into exact correspondence with folders on the left. Changed files will be replaced, new ones will be added, deleted files will be deleted.

4.3. Comparison of reserved folders

Before starting a backup, you must first compare your folders with the backup folders. To do this, click the “Compare” button.

If this is your first backup and you have not created empty folders for backups, a message will appear indicating the folders that were not found.

Please note that these errors may be caused by an error in the path to the main backup folder (in in this example“Backup”) or lack of access to another computer over the network (in this example, “HOME-2”).

After comparing the folders, you will see a list of files being copied, updated and deleted and their total size.

The first time you perform a backup, you will only have files that are being added; the next time you back up, you will see those that are updated and deleted, depending on the changes you made. Renamed files will be deleted from the backup and files with a new name will be copied in their place.

4.4. Creating a Backup

Make sure that the result of the comparison, the expected actions and the volume of copied files look plausible and click the “Synchronize” button that becomes active.

A message will appear again warning about the actions being performed, in which you need to confirm the start of the backup with the “Start” button.

Depending on the size of the files, the speed of the external drive or the local network, the backup process may take different times. But the program itself does it as quickly as possible.

Hard drive A-Data Ultimate SU650 120GB

The first backup may take a long time if there is a large volume of files. All subsequent backup updates take significantly less time. The backup ends with a success message.

Various errors and warnings may occur during the backup process. Most of them are not essential (for example, some service or temporary file cannot be copied). Make sure that the error is really not significant and click the “Ignore” button.

5. Folder synchronization

Folder synchronization may be necessary if you work with the same files on several computers, for example, at home and at work. In this case, to ensure that the files are the same everywhere, you can use an external drive or flash drive for synchronization.
Transcend JetFlash 790 8Gb

5.1. Selecting folders to sync

Open the program on a computer with the latest version of your files. In the left pane, add folders with your files, and in the right pane, select folders on your external drive or flash drive that will be used for synchronization.

When synchronizing files between multiple computers, it does not matter which folders are on the right and which on the left. But to avoid confusion, I recommend that you always select files that are on your computer on the left, and files that are on an external drive or flash drive on the right.

To add another pair of folders, use the plus sign “+”; to search for a folder in Explorer, use the “Browse” button. You can also enter folder paths in whole or in part manually, copy and paste paths and folder names into the required fields. If the folder you want to use for synchronization does not exist, it will be created during the first synchronization.

Store often mutable files in separate folders (for example, Documents) so that they do not get mixed up with large immutable files (for example, movies). Then synchronization will require significantly less time and space on an external drive or flash drive.

5.2. Selecting the synchronization mode

Now go to the synchronization settings using the gear icon next to the “Sync” button.

Select the synchronization mode “Both directions” and click “OK”.

Make sure the Synchronize button is set to Both Ways.

In this mode, when synchronizing, folders located on the left and right will be brought into exact correspondence. In this case, all changes on both sides will be taken into account. Changed files will be replaced, new ones will be added, deleted files will be deleted. To do this, a database is used, consisting of special service files that the program creates in each synchronized folder.

Thanks to the database, you can make changes on several computers independently of each other, and even on the external disk or flash drive itself, using some other computer that is not involved in synchronization. During the next synchronization, the program itself will determine which changes are the latest and gracefully bring folders with files to the final version, even if you missed the previous synchronization and have already forgotten on which computer and which files you changed. The program will accurately determine this itself using the database.

5.3. Comparison of synchronized folders

Before you start synchronizing, you must first compare the folders on your computer drive with the folders on your external drive or flash drive. To do this, click the “Compare” button.

If this is your first synchronization and you have not created empty synchronization folders on an external drive or flash drive, a message will appear indicating the folders that were not found.

Click the "Ignore" button.

Please note that these errors can be caused by an incorrect drive letter ("F" in this example), as letters can sometimes change, or problems with connecting the external drive or flash drive (such as a bad cable or lack of power).

After comparing the folders, you will see a list of files being copied, updated and deleted on both sides and their total size.

At the first synchronization you will only have files that are being added; at subsequent synchronizations, you will see updated and deleted ones, depending on the changes you made. Renamed files will be deleted and files with a new name will be copied in their place.

5.4. Start synchronization

Make sure that the result of the comparison, the expected actions and the volume of synchronized files look plausible and click the “Synchronize” button that becomes active.

A message will appear again warning about the actions being performed, in which you need to confirm the start of synchronization with the “Start” button.

Depending on the size of the files, the speed of the external drive or flash drive, the synchronization process may take different times. But the program itself does it as quickly as possible.

The first synchronization with a large volume of files may take a long time. All subsequent synchronizations take significantly less time. Synchronization ends with a success message.

Various errors and warnings may occur during the synchronization process. Most of them are not essential (for example, some service or temporary file cannot be copied). Make sure that the error is really not significant and click the “Ignore” button.

5.5. Sync on another computer

To synchronize folders on another computer with an external drive or flash drive, you need to install the FreeFileSync program on it, configure and perform synchronization on it in the same way (section 5.1-5.4).

Also, when installing the program, you can select the “Portable” version and install the program on an external drive or flash drive, which will be used for synchronization. It is recommended to use this method if it is not possible to install the program on another computer (for example, at work).

6. FreeFileSync program settings

The program has a few settings and they are all quite clear and useful.

The program remembers the latest folders for synchronization. But it’s still better to save the synchronization settings to a file using the “File/Save” menu.

Using the "File" menu you can create new configuration or open an existing one. This way, you can create several different configurations, for example, separately for backing up files on a second home computer and separately for synchronizing documents using a flash drive with a work computer.

If you select “Save as a batch job,” this file can be used to manually run a backup, synchronize folders, or specify it in the scheduler for automatic scheduled backups.

If you plan to run a batch job automatically according to a schedule, then when saving you can set error handling to “Ignore”, the “Run minimized” checkbox, and the completion action “Close the process window” or “Turn off the computer” (for backup at the end day).

The settings file and batch job have corresponding icons and can be launched without opening the main program.

6.2. Compare, filter and synchronization settings

From the “Actions” menu you can go to “Comparison Settings”, “Filter Settings” and “Synchronization Settings”.

In the comparison settings, you can set “File content” instead of the “Date and file size” mode, but this is not recommended, as it will greatly slow down the speed of the program.

In the left panel, you can select folders and set comparison settings for each of them individually. It is also possible to enable copying of symbolic links if you know why this is needed.

In the filter settings you can exclude separate files and folders from backup.

For example, if your D:\Documents folder contains a Videos folder with large files, which you have already copied somewhere, then to exclude it from synchronization you need to add the line “D:\Documents\Video\” to the “Exclude” section. If you want to exclude from the backup copy all installers of programs that can be downloaded from the Internet, then add the line “*.exe” to the “Exclude” section.

In the left panel, you can select folders and set filter settings for each of them individually.

Using the fields on the right, you can filter files unnecessary for synchronization based on the time period from their last change and size. This way you can weed out, for example, files that are too old and too large.

Synchronization settings

Synchronization settings are the most important, the most useful, and allow you to have flexible control over the process of creating backups or synchronizing folders.

The following synchronization options are available.

Both ways	Used to synchronize folders between multiple computers. The folders on the left and right are brought into full compliance using the change database. Files are copied and deleted in both directions.
Mirror	Used for backup. The folders on the right are fully consistent with the folders on the left. Files are copied only from left to right; files deleted on the left are also deleted on the right.
Update	New and changed files in the folders on the left are copied to the folders on the right, but files deleted in the folders on the left are not deleted from the folders on the right. This may be necessary when you need to save old files in a backup copy.
Selectively	Allows you to configure your own synchronization rules when detecting new, changed and deleted files on both the left and right. Can be used to solve some specific problems.

In all modes, except for “Both-Way” synchronization, you can set your own rules for new, updated and deleted files.

There is also a “Detect moved files” option, which is useful if you often clean out folders. In this case, the files will not be copied again, but will simply be moved to the copies.

Just below you can configure the settings for deleting files - “Delete permanently”, “Add to Trash” or “Archive”.

By default, files located on hard drives, are removed to the trash. If you make a mistake with the synchronization settings and some necessary files, then they can be restored.

Files on flash drives and network folders are not deleted to the trash. They can only be recovered using special file recovery programs. If you make a mistake, then do not do anything with the flash drive or disk until you recover the necessary files from them.

When you select the “Archive” option, the files will not be deleted, but will be moved to the user-specified folder.

If you need to synchronize a large amount of data and there is no way to control the process, then it is recommended to set the “Error Handling” option to “Ignore”. You can also select the desired action to complete synchronization, for example, turn off the computer.

Synchronization settings can also be set for each individual folder by selecting it in the left panel.

6.3. Other settings and tools

From the “Tools” menu, you can go to “Settings” of the program itself, change the “Language” of the interface, “Find” files and folders in the comparison results, “Reset the location” of all folders and “Export a list of files” to a text document.

By default, “Fault-tolerant file copying” is enabled in the program settings, which makes backup or synchronization more reliable.

You can enable “Copy blocked files” if such problems occur. The “Copy DACL, SACL, Owner, Group” option allows you to copy file permissions if you have set such restrictions and want to save them in a backup copy to restrict access to them or later restore files along with security settings.

I do not recommend experimenting with security settings, especially file encryption, for inexperienced users. This may result in permanent loss of access to files in the event of a system failure or user error.

“Automatic retry on errors” allows you to set the number of attempts to copy files and the interval between attempts in case of temporary problems with the network or media.

Below are the rules for customizing the context menu for experienced users with reference to examples of their use.

Show button hidden windows again” restores displays that you previously disabled using the “Ignore subsequent errors” checkbox.

The “Default” button returns all program settings to initial state. Use it when you are not sure that you have configured everything correctly.

Well, don’t forget to confirm all changes made with the “OK” button.

7. Real-time backup

Here we will look at the additional utility RealTimeSync, which is installed along with the main program and is used for automatic synchronization.

Open the utility using the RealTimeSync shortcut on your desktop or START menu, go to the File menu and select Open.

Leave in the “Folders for monitoring” section only folders with files on the computer disk, and delete folders with a backup copy on an external drive, flash drive or local network.

Set the time in seconds after which you would like to check folders for modified files. For example, by setting 3600 seconds, folders will be scanned every hour from the start of monitoring. All that remains is to click the “Start” button, the program will minimize to the system tray (in the icon next to the clock) and begin monitoring the folders.

If changes to files in the specified folders occur during the next scan, the program will start the synchronization process, which will end with the display of the corresponding window.

If the “Run minimized” checkbox is checked in the batch job settings, this message will not be displayed and synchronization will be performed in silent mode.

If, at the time of detecting changes in folders, the utility will not be able to access an external drive, flash drive or network folder with backup copies, a corresponding message will appear.

If in the batch job settings the “Error Handling” option is set to “Ignore”, then this message will not be displayed and synchronization will occur when access to the device with backup copies is resumed.

Among the advantages of the RealTimeSync utility, one can note the ease of its setup and use, but it also has several disadvantages. Firstly, you need to launch it manually or set up startup yourself along with Windows (for example, by copying the shortcut to the “Startup” folder in the “START” menu). Secondly, it does not allow you to set a flexible schedule for synchronization. And thirdly, sometimes synchronization does not work.

8. Scheduled backups

As an alternative to the RealTimeSync utility, you can use the Windows Task Scheduler, which does not have all of the listed disadvantages and has more flexible capabilities.

Go to “Control Panel\System and Security\Administrative Tools” and select “Task Scheduler” or “Task Schedule”.

Select "Create a simple task."

Enter a meaningful name for the task and click on the “Next” button.

Select how often you would like to back up.

Then, be more specific about the day and time that your computer is likely to be turned on to sync. For example, every Friday at 17:00.

Select an action for the Run a program task.

Click the Browse button.

Select the batch job file created in FreeFileSync.

Click the "Done" button.

Now files will be backed up exactly on the appointed day and time. If the computer is turned off at this time, the task will be completed the next time it is turned on. Just make sure that the backup media is available at the right time.

You can delete or change backup settings at any time in the Task Scheduler Library.