Folder Synchronization Utilities

Directory synchronization is the process of keeping two directory trees synchronized, such that changes made to objects in one tree are propagated automatically to the other tree. In case of vast directory trees this is a complex task. Please note that directories can not only be removed, but also can be renamed or relocated to a different part of the tree. The same is true for files.

In the simplest form (no renaming of files of folders and no move of file or folders to different subdirectories) you can use diff against listing of updated files on Folder 1 (left folder) and Folder 2 (right folder) that you want to syncronize. Here is how accomplish this in Cygwin:

find /Folder_a -newer  /Folder_a/centinel -ls > /tmp/folder_a_map
find /Folder_a -newer  /Folder_a/centinel -ls > /tmp/folder_a_map
diff folder_a_map folder_b_map >/tmp/$1\_$2\_diff
egrep "^<" /tmp/ $1\_$2\_diff  > /tmp/$1\_newer
egrep "^>"  /tmp/$1\_$2\_diff  >/tmp/ $2\_newer
cat /tmp/$1\_newer | xargs -1 cp $1\{} $2
cat /tmp/$2\_newer | xargs -1 cp $2\{} $2

Synchronization is different from mirroring options. You might have mirrored a company document directory to your laptop, for example, and then modified a document or two. Other people might have modified other documents in the same directory by the time you get back. With rsync, you'd need to reconcile the differences between the two directories manually or risk overwriting someone's changes.

Directory synchronization tools like OFM managers (for example Total Commander) can sort out what has changed where, propagate the changed files.

Specialized tools like Unison  can even merge different changes to the same file if you tell them how.

There is one Perl-based implementation  Reflect

Microsoft has free tool called SyncToy 2.1 (Windows only, but can sync to any shared folder). SyncToy is a simple tool that synchronizes files between two folders (located on the same PC or on different computers).

Download the SyncToy 2.1 and install it on one PC that will be syncing with another. Start up SyncToy and click "Create New Folder Pair" to define a "Left Folder" and a "Right Folder." Files will initially sync from left to right, so choose the folder with the source files on the left and the destination on the right. If you're syncing to another computer entirely, you will need to share the folder so that your computer can open and save files to it. (Here's more on how to share files from a PC, and how to share a folder on a Mac.)

After you've chosen the Right Folder on the other PC, click the Next button. Select Synchronize as the Folder Pair action, and click Next to name your pair something descriptive, such as "Family room photo sync." Click the Finish button.

From here, you can configure, test, or run your new folder pair action, as shown. Here is quote from Microsoft Download page:

Overview
There are files from all kinds of sources that we want to store and manage. Files are created by our digital cameras, e-mail, cell phones, portable media players, camcorders, PDAs, and laptops. Increasingly, computer users are using different folders, drives, and even different computers (such as a laptop and a desktop) to store, manage, retrieve and view files. Yet managing hundreds or thousands of files is still largely a manual operation. In some cases it is necessary to regularly get copies of files from another location to add to primary location; in other cases there is a need to keep two storage locations exactly in sync. Some users manage files manually, dragging and dropping from one place to another and keeping track of whether the locations are synchronized in their heads. Other users may use two or more applications to provide this functionality.

Now there is an easier way. SyncToy, a free PowerToy for Microsoft Windows, is an easy to use, highly customizable program that helps users to do the heavy lifting involved with the copying, moving, and synchronization of different directories. Most common operations can be performed with just a few clicks of the mouse, and additional customization is available without additional complexity. SyncToy can manage multiple sets of folders at the same time; it can combine files from two folders in one case, and mimic renames and deletes in another case. Unlike other applications, SyncToy actually keeps track of renames to files and will make sure those changes get carried over to the synchronized folder.

SyncToy2.1 is powered by the latest synchronization engine from Microsoft Sync Framework 2.0 and provides better performance and robustness. The new features and improvements included in SyncToy 2.1 release are:

• Better Performance: The speed of file copy operations is significantly increased across the board.
• Improved Robustness: Much more resilient to transient network and file system errors and better error reporting which pin-points which file the sync failed on in case there’s a fatal error that stops the sync.
   
• Folder pair configuration backup: Folder pair configuration is automatically backed up under %localappdata%\microsoft\synctoy\2.0. User can replace SyncToyDirPairs.bin with the backup copy to resolve last saved configuration.
   
• Bug Fixes:
   
  • Fixed the data corruption issue when using SyncToy with NAS drives.
     
  • Fixed the issue that prevented uploading files to SharePoint when using SyncToy 2.0.
     
  • Fixed the issue that prevented delete changes from being synchronized when the sync option is set to “Echo”.
     
  • Fixed the UI issue where reported file time were off by the difference between local time and UTC when destination is a FAT volume.
     

The major new features and improvements included in previous SyncToy 2.0 release are:

• Dynamic Drive Letter Assignment: Drive letter reassignment will now be detected and updated in the folder pair definition.
   
• True Folder Sync: Folder creates, renames and deletes are now synchronized for all SyncToy actions.
   
• Exclusion Filtering Based on Name: File exclusion based on name with exact or fuzzy matching.
   
• Filtering Based on File Attributes: The ability to exclude files based on one or more file attributes (Read-Only, System, Hidden).
   
• Unattended Folder Pair Execution: Addressed issues related to running scheduled folder pairs while logged off.
   
• Folder Pairs With Shared Endpoints: Ability for folder pairs associated with the same or different instances of SyncToy to share end-points.
   
• Command line enhancements: Added the ability to manage folder pairs via the command line interface.
   
• Re-Architect Sync Engine: The SyncToy engine has been rearchitected to provide scalability and the ability to add significant enhancements in future releases.
   
• Sync engine is also more robust insomuch that many single, file level errors are skipped without affecting the entire sync operation.
   
• Sync Encrypted Files: Sync of Encrypted files works when local folder and files are encrypted, which addresses the common scenario involving sync between local, encrypted laptop PC folder and remote, unencrypted desktop PC folder.
   
• 64-Bit Support: SyncToy now has a native 64-bit build (x64 only) for 64-bit versions of Windows.
   
• Folder pair rename
   
• Sub-folder Exclusion Enhancements: Descendents created under excluded sub-folders are automatically excluded. Usability improvements for the sub-folder exclusion dialog.
   
• Folder Pair Metadata Moved: Folder pair metadata removed from MyDocuments to resolve any issues with server-based folder pair re-direction setup.
   
• Setup Improvements: Integrated setup with single self-extracting archive file and no extra downloads if you already have .NET Framework 2.0 installed. Enabled silent install for the SyncToy Installer file (see readme.txt file for more information).
   

Please continue to send us feedback about our tool, using the SyncToy - File Synchronization forum (listed below).

Note: We've taken great care to ensure that this tool operates as it should, but it is not part of Windows and is not supported by Microsoft Technical Support. For this reason, Microsoft Technical Support is unable to answer questions about SyncToy. To speak to other users and contribute feedback about your experiences with SyncToy, please use the SyncToy forum at http://social.microsoft.com/Forums/en-US/synctoy/threads.

NEWS CONTENTS

• 20110529 : Super Flexible File Synchronizer freshmeat.net ( Super Flexible File Synchronizer freshmeat.net, May 29, 2011 )
• 20110123 : DirSync Pro 1.4 ( DirSync Pro 1.4, Jan 23, 2011 )
• 20110123 : dircmp - search.cpan.org ( dircmp - search.cpan.org, )
• 20100306 : YADSync freshmeat.net ( YADSync freshmeat.net, Mar 6, 2010 )
• 20080618 : Project details for rdiff-backup ( Project details for rdiff-backup, Jun 18, 2008 )
• 20080513 : Unison - file synchronization tool -- Ubuntu Geek ( Unison - file synchronization tool -- Ubuntu Geek, May 13, 2008 )
• 20080125 : Directory Synchronize 0.92 by F. Gerbig ( Directory Synchronize 0.92, Jan 25, 2008 )
• 20071212 : Folder Synchronizer Programs Review ( Folder Synchronizer Programs Review, Dec 12, 2007 )

Old News ;-)

[May 29, 2011] Super Flexible File Synchronizer freshmeat.net

Super Flexible File Synchronizer lets you back up your data and synchronize PCs, Macs, servers, notebooks, and online storage space. You can set up as many different jobs as you need and run them manually or by using the scheduler. The software works with local hard drives and any other mounted volumes. In addition, it comes with support for FTP, SSH, HTTP, WebDAV, Amazon S3, and Google Docs. You can use Zip compression and data encryption. There are powerful synchronization modes, including Standard Copying, Exact Mirror, and SmartTracking.

[Jan 23, 2011] DirSync Pro 1.4

Java-based, GPL licensed.

DirSync Pro is a powerful, easy-to-configure tool to synchronize the contents of one directory with another. It can compare files by various attributes, such as size or modified-date. It can synchronize... an unlimited number of directories, and has a detailed logging function.

dircmp - search.cpan.org

dircmp - directory comparison

use File::Dircmp;

@r = dircmp($dir1, $dir2, $diff, $suppress);

DESCRIPTION

The dircmp command examines dir1 and dir2 and generates various tabulated information about the contents of the directories. Listings of files that are unique to each directory are generated for all the options. If no option is entered, a list is output indicating whether the file names common to both directories have the same contents.

The algorithm I use orders the report differently than the unix commands. There is no option to control the length of the output.

OPERANDS

$dir1 A path name of a directory to be compared.

$dir2 A path name of a directory to be compared.

$diff Compare the contents of files with the same name in both directories and output a list telling what must be changed in the two files to bring them into agreement. The list format is described in diff(1).

$suppress Suppress messages about identical files.

TODO

Implement the $diff argument.

AUTHOR

Josh Schulte <[email protected]>

[Mar 6, 2010] YADSync freshmeat.net

Written in Python Uses PyGTK Glade

YADSync (yet another directory sync) is a simple tool to easily synchronize a set of directories. This allow you to save your important documents in different locations.

[Jun 18, 2008] Project details for rdiff-backup

freshmeat.net

About:
rdiff-backup backs up one directory to another. The target directory ends up a copy of the source directory, but extra reverse diffs are stored in a special directory so you can still recover files lost some time ago. The idea is to combine the best features of a mirror and an incremental backup. rdiff-backup can also operate in a bandwidth- efficient manner over a pipe, like rsync. Thus you can use rdiff-backup and ssh to securely back up to a remote location, and only the differences will be transmitted. It can also handle symlinks, device files, permissions, ownership, etc., so it can be used on the entire file system.

Release focus: Major bugfixes

[May 13, 2008] Unison - file synchronization tool -- Ubuntu Geek

Unison runs on both Windows and many flavors of Unix (Solaris, Linux, OS X, etc.) systems. Moreover, Unison works across platforms,allowing you to synchronize a Windows laptop with a Unix server, for example.

Unlike simple mirroring or backup utilities, Unison can deal with updates to both replicas of a distributed directory structure.

Updates that do not conflict are propagated automatically. Conflicting updates are detected and displayed.

Unlike a distributed filesystem, Unison is a user-level program: there is no need to modify the kernel or to have superuser privileges on either host.

Unison works between any pair of machines connected to the internet, communicating over either a direct socket link or tunneling over an encrypted ssh connection. It is careful with network bandwidth, and runs well over slow links such as PPP connections. Transfers of small updates to large files are optimized using a compression protocol similar to rsync.

Unison is resilient to failure. It is careful to leave the replicas and its own private structures in a sensible state at all times,
even in case of abnormal termination or communication failures.

Unison has a clear and precise specification.

Unison is free; full source code is available under the GNU Public License.

[Jan 25, 2008] Directory Synchronize 0.92 by F. Gerbig

The tool written in Java

About: Directory Synchronize is a powerful, easy-to-configure tool to synchronize the contents of one directory with another. It can compare files by various attributes, such as size or modified-date. It can synchronize an unlimited number of directories, and has a detailed logging function.

Changes: It is now possible to keep multiple backups of changed or deleted files. Wildcards for the global log and wildcards regarding user information (name and home directory) have been implemented. Bugs regarding NullPointerExceptions in console mode and the bug that wildcards would be written back to the directory definition have been fixed.

[Dec 12, 2007] Folder Synchronizer Programs Review

programs reviewed

1. unison

   1. The developers state no new features will be added to the program.

   2. The gui is quite basic, and you will need to edit configuration files as well.

   3. uses the obscure OCaml language, so may be more difficult to customise if needed.

   4. Uses efficient rsync protocol to sync over a network.

2. xfiles

3. jfilesync

   1. needs Java 5.0, which will mean another download for most users.

   2. GUI has a few quirks - e.g. you have to click 'compare' to get it to show conflicts

   3. you can't launch a 'diff' program from within the GUI

   4. easy to use

   download here There is another program by the same name at http://home.arcor.de/mschierlm/sm-soft/jfilesyn-en.htm. The one reviewed is at the link above

4. directorysync

5. FileSync

6. foldermatch

7. HAS (Heatsoft Automatic Synchronizer)

8. Allway Sync

   1. No mailing lists, public bug database, or other user community.

   2. the only reviewed proprietary program with update detection

   3. allways sync is also known (or was previously known) as GoodSync

   4. note mispelling in name

9. MS synctoy

   1. Windows XP only

   2. detects rename

   3. uses the update detection algorithm for deletions only, not updates. Overwrites edits in the older file when there are conflicts

   4. requires .net to be installed

   5. 512Mb ram & a P4 is recommended

   6. requires you to download an additional program to 'validate' you have registered your installation of XP

   7. only allows a single pair of folders per profile

summary

There are some features that you would expect to see in these programs that are in none - for example being able to use a non re-writable media like a cd-rw (not in packet writing mode) to synchronize two machines. Other basic features (namely client server / update detection) are only in a few programs.

I think this is because it is easy to write a simple directory differencer, so many would-be shareware developers use it as 'My first Program'.

Unfortunately the simple, obvious way of doing this is the wrong way.

In both these respects it is similar to duplicate file finders.

As usual, the open-source programs might not have the pretty GUIs of the proprietary ones, but get more of the basic features right.

If more than about a dozen files are changed with each sync, then any sync program is effectively unusable without update detection. Currently the only 3 programs that support this are unison, jfilesync & AllwaySync.

Of these 3, AllwaySync does not have a client/server mode, does not have the user community of the other 2 programs (so is more likely to have unfound bugs) and is closed source.

The unison developers state no new features will be added to the program. The unison gui is quite basic, and you will need to edit configuration files as well. Unison uses the OCaml language, so may be more difficult to customise if needed.

jfilesync needs Java 5.0, which will mean another download for most users.

JFileSync has a few UI quirks but overall it works well.

So for most purposes I recommend jfilesync.

If you need to sync a large amount of data over the internet, use unison instead because of its more efficient compressed protocol.

[Dec 11, 2007] Using Unison to synchronize files between windows and solaris

This document describes how to setup Unison to perform synchronization between a windows laptop and a solaris system.

What I am trying to achieve is to use the Windows version of Unison, as compiled by Max Bowsher. This version unfortunately has a problem asking for password for the ssh account but following this document should provide an acceptable alternative.

What I do is run Unison on the laptop and make it ssh to the solaris system where the remote files are stored (and backed up).

For this to work, you will need to install a few Cygwin packages (for ssh) and manually install Unison for windows and at last, set it up so we can avoid the bug mentioned above.

[Dec 11, 2007] FileSyncingHowTo - MineZone Wiki

I've been a big fan of all the life hacks sites and tutorials that have sprung up recently. In Danny O'Brien's original Life Hacks presentation, he mentioned file synchronization as one of the tools common to the most productive users. Prior to hearing that, I had tried several times to set up file synchronization between my home and work PCs and always ran into snags.

Thanks to inspiration from the Life Hacks presentation, I finally persevered. The result is a combination of four open source tools: copSSH, putty, Unison, and WinMerge that allow me to quickly synchronize my files on a daily basis. I encountered quite a few road blocks in the process, which I will do my best to document here.

I've been using this setup successfully for months. I synchronize files once when I get to work and once before I leave and I'm able to work on all the same files, in the same directories, regardless of which PC I'm on. I can confirm that it has indeed been a productivity boon.

[PDF] File Synchronization with UNISON Introduction

[Sep 04, 2007] Keep your laptop and PC in Unison by Federico Kereki

September 04, 2007 | Linux.com

I usually carry my laptop everywhere and do work on it, but I do also need to work at my desktop PC, so I need to synchronize the files on the two machines. I have used several sync tools in the past, ranging from simple commands like scp and rsync to utilities like Krusader, which includes a way to synchronize directories on different machines. Recently I started using Unison.

Unison can synchronize files between Unix, Linux, and Windows machines; for example, you could synchronize a Windows laptop with a Unix server with the same ease as you would synchronize two Linux machines. You can use it with any two machines connected over the Internet, and it can use an encrypted SSH connection for extra security.

Unison is freely available under the GNU GPL. Its development seems to be at a halt right now, with no one specifically on charge of maintenance or bug fixes. However, the site explains that the original developers are still using the program, and continue to maintain and support it, and (on occasion) release new bug fixes or small changes. The current stable version at the site is 2.13.16, but there's a beta version 2.27.29 (quite a jump!) and the current development, unstable, version is 2.28.15.

Since it has been around for some time, most distributions' repositories include it. I use openSUSE (both 10.1 and 10.2), and installing Unison was a breeze. A curious point: on openSUSE 10.1 I got the 2.13.16 version, but on 10.2, I got a newer 2.17.1 one. That posed a problem, because you must have the same version of the program in both machines, so I went to rpmseek.com and got the 2.17.1 version for my openSUSE 10.1 box.

WinSCP -- Directory Synchronization

WinSCP can synchronize content of local directory with remote one or vice versa or even mutually. Find the function in Commands > Synchronize. Synchronize dialog will appear, where you can select synchronization mode and configure options.

Once you confirm your options, WinSCP will collect list of differences in between the directories. If option Preview changes is enabled, you will be presented with the synchronization checklist, where you can select those synchronization actions you want to actually apply.

Files and directories excluded from transfer are excluded from synchronization too.

Before using the function make sure that WinSCP knows correct timestamps of remote files, to avoid losing data.

If you use WinSCP to synchronize your files only, you can use command-line parameter /synchronize to quickly open Synchronize dialog.

freshmeat.net Project details for DirSync

DirSync is a directory synchronizer that takes a source and destination directory as arguments and recursively ensures that the two directories are identical. It can be used to create incremental copies of large chunks of data. For example, if your file server's contents are in the directory /data, you can make a copy in a directory called /backup with the command "dirsync /data /backup." The first time you run it, all data will be copied. On subsequent runs, only the changed files are copied.

Author:
Mario Viara [contact developer]

Homepage:
http://www.viara.cn/en/dirsync.htm
Tar/GZ:
http://www.viara.cn/download/dirsync-1_11.tar.gz
Zip:
http://www.viara.cn/download/dirsync-1_11.zip

[Nov 9, 2005] Folder Syncronization PowerToy

Rather weak, but might be OK for stall directory trees/still very buggy for large trees (say over 40K files). It simply does not work with large trees. Does not permit regular expressions in specifing what folder you need to exclude (important for Frontpage)

Microsoft has released another Power Toy that will syncronize data between either local or network folders. SyncToy v1 is a free download and it should be noted that it is in beta.

This entry was posted on Thursday, August 11th, 2005 at 10:49 am and is tagged with the terms cool utilities. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

[Nov 9, 2005] AASync Beta version 0.9.1 is here! Easy-to-use FTP - SFTP Folder Synchronization

Chokes on large trees...

AASync is a File Backup, Folder Syncronization utility. It is simple to use, and it allows local as well as remote backups over an FTP or SFTP connection. Makes it very easy to back up your files to a remote server or another local disk or maintain your website! The sync engine will detect the changes, and copy only the changed files for efficiency. Here are the main features:

Folder Synchronization: Local-to-Local, Local-to-Remote (any protocol) and Remote-to-Local (SFTP/SSH only). If folder sync's target is a local or remote Mac with ssh access, fork/type/creator data is preserved!

Retains fork data, type/creator and attributes on Mac-to-Mac transfers (local AND remote).

Scheduled Sync.

Ability to ignore certain files or file types.

Why AASync? What is the point, you may ask.. well here it is: Most File backup utilities can only deal with source and target folders that are mounted on the local system, like an external disk. Well, that is better than nothing, for sure, but it will not offer a lot of data protection. What does? An offsite backup meaning a daily syncronization of certain folders on your desktop to a remote host! Remote meaning a host in a different location, with which we communicate using some protocol like SFTP-SSH or FTP. AAsync will do the local sync like everybody else, but it also does Local-to-Remote and Remote-to_local sync. Remote-to_local sync is very rare, very few apps can do it, and none like AASync. AASync does NOT require any custom software to run on the remote host, all that is required is that you have a regular FTP or SFTP account, and that is it (Remote to Local sync requires SFTP or an SSH shell account)!

File Synchronization with Unison by Erik Inge Bolso

2005-03-01 | Linux Journal

Keeping directories in sync on multiple machines can be difficult. Running Unison is one way to make the task easier.

Unison is a file-synchronization tool that runs on Linux, UNIX and Microsoft Windows. Those of you who've used IBM Lotus Notes or Intellisync Mobile Suite probably have an idea of what synchronization is good for, as compared to one-way mirroring options such as rsync. You might have mirrored a company document directory to your laptop, for example, and then modified a document or two. Other people might have modified other documents in the same directory by the time you get back. With rsync, you'd need to reconcile the differences between the two directories manually or risk overwriting someone's changes. Unison can sort out what has changed where, propagate the changed files and even merge different changes to the same file if you tell it how.

Think of Unison as two-way rsync with a bit of revision control mixed in. The most common use is keeping your local and remote home directory, or some data directory you often use in different contexts, in sync. It uses the rsync algorithm to keep network traffic down and should be tunneled through SSH over untrusted networks. No extra work is needed-simply specify ssh:// when adding a directory location. Quite a bit of extra disk space often is needed for Unison, though, because the synchronizer needs to keep track of what the files looked like on the last run.

Getting, Compiling and Installing Unison

Unison's home page is maintained at the University of Pennsylvania; the project leader, Benjamin C. Pierce, is a professor in the Department of Computer and Information Science. See the on-line Resources for the URL.

Unison isn't as widely deployed as rsync, so you might not be able to find a precompiled package for your distribution. But the binaries downloadable from the Unison home page should work for most people.

If you'd like to compile from source, you can. A few extra hoops must be jumped through, however, because Unison is programmed in OCaml, not the most common language. See Resources if there is no handy package for your distribution.

Compiling and installing Unison is simple; type make UISTYLE=xxx. The GTK user interface needs additional OCaml bindings for GTK, so I use the text interface in this article. Typing make UISTYLE=text or make UISTYLE=gtk should give you a Unison executable. Simply copy the executable to somewhere in the path on both machines you want to synchronize.

In this article, I'm using the current stable version of Unison, 2.9.1, unless otherwise noted. You need to use the latest betas if you're going to synchronize files larger than 2GB.

The developer versions tend to work well. They are what the developers run themselves on their own precious data. Sign up for the unison-hackers mailing list if you feel a bit adventurous. Jerome Vouillon, Benjamin C. Pierce and Trevor Jim tend to hang out there discussing improvements. Commit logs also float by, so you can track what is going on.

Configuring and Using Unison

Unison keeps its config and working files in a .unison directory in your home directory or wherever you want to put it. Set the UNISON environment variable to specify an alternate location.

The default configuration is stored in .unison/default.prf. Listing 1 shows a plain config file suitable for testing. Synchronizing two directories is now as simple as:

$ unison /nfsmount/dir1 /home/me/dir1 

Listing 1. .unison/default.prf

# Unison preferences file merge = diff3 -m CURRENT1 OLD CURRENT2 > NEW backup = Name * maxbackups = 10 log = true logfile = /home/knan/.unison/unison.log rshargs = -C 

Unison then asks the user about any differences between the directories and offers reasonable defaults. It does take a bit of time to get used to Unison's way of thinking, however. And, Unison is no substitute for backups. Unison happily propagates back the deletion of all the files in one replica, for example, which can be a rude awakening for programmers used to CVS. For example:

rm dir1/* ; unison ssh://server/dir1 dir1 

doesn't do what you expect from a:

rm dir1/*; cvs update dir1 

Deleting a file is an action that is replicated on the other side upon synchronization. So, this example command removes all files in dir1 on both sides.

Once you feel comfortable, consider adding auto = true to the Unison profile. This skips questions about any non-conflicting changes but gives you a chance to back out at the end.

The Unison manual is recommended reading. It is clear and well written and explains what happens at most corner cases.

Keeping Home Directories in Sync

Once users become familiar with Unison, a common thought is to use it for keeping one's home directory in sync between machines, say, your laptop and desktop. This can be realized pretty easily. Listing 2 has a simple profile that does the job, but you probably want to extend it. Listing 2, for example, ignores MP3 files and Unison's own files and demonstrates the use of include for having common settings applied to all profiles.

Listing 2. .unison/home.prf

# Unison preferences file root = /home/erik root = ssh://remotehost/home/erik # exactly two or none "root" lines ignore = Name *.mp3 # ignore all .mp3 files anywhere ignore = Path .unison # ignore all files with .unison somewhere in their full path include default # imports settings from default.prf 

Test our new profile like this:

$ unison home -testserver 

And invoke it like this:

$ unison home -batch $ unison home 
 

The -batch run takes care of the easy cases without asking, backing up and logging as needed, and the second run asks you about any tricky business-like merging.

The root = lines can be omitted if you want to specify the files to be synchronized on the command line instead. The lines are equivalent to this invocation:

$ unison home /home/erik ssh://remotehost/home/erik 

Merging Conflicting Changes

In order to do a three-way merge, backups must be enabled. By default, with backups disabled, Unison keeps only a checksum and metadata, such as permissions, so it has no unmodified file to reference.

In version 2.9.1 of Unison, if you choose merge for a conflict and the merge is successful without manual intervention, the changes are propagated immediately, which doesn't give you a chance to back out. So, if you have the space, I suggest leaving maxbackups at 5 or so, instead of the default 2, to leave yourself the chance of recovering from automatic mismerges. Contents of the backup directory after a merge look like this:

$ ls -1 .unison/backup/ shared.txt merged version ("NEW") shared.txt.1.unibck changed remotely ("CURRENT2") shared.txt.2.unibck changed locally ("CURRENT1") shared.txt.3.unibck old version ("OLD")

As of the newest beta, 2.10.3 at the time of this writing, Unison can invoke different merge programs for different files. You might want to use 3DM to merge XML files, for example, or a database merge tool for your Berkeley databases. This functionality still is new and subject to change. It has been noted by the project leader that the merge functionality was in need of a rewrite and didn't really work too well in 2.9.1 and 2.9.20. Thus, if you intend to do much merging, you will be better off tracking the bleeding edge.

Resources for this article: www.linuxjournal.com/article/8059.

Erik Inge Bolsø is a UNIX consultant and épée fencer who lives in Molde, Norway, and has been running Linux since 1996. Another of his hobbies can be found by doing a Google search for "balrog genealogy", and he can be reached at [email protected].

Absolutely free software .folder sync utility v.10

Folder Synchronization - The easiest way to synchronize two folders -- for Windows NT and 9x; $15.

Folder Synchronization is designed to work with Windows95, Windows98 and WindowsNT.

Feature List:

• Easy to use interface.
• Control what gets copied on single-file or summary basis.
• Control the default operations to minimize your work.
• Keep a copy of deleted files on the server.
• Optionally get a detailed log of all operations.
• Take part in a server backup concept.

What's new for Version 1.1

• Comparison of Filenames is not any more case sensitive.
• The settings are now stored independent of how you exit.

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Folder Synchronizer Programs Review

Unison (file synchronizer) - Wikipedia, the free encyclopedia

unison-manual

Philip Guo - Unison File Synchronizer Liberation through Data Replication by Philip Guo

Reconcile Users' Guide Date: September 1999 Author: John H. Howard

Reconcile combines different versions of file directories, propagating all updates between them and making them identical but never losing updates at one site because of updates performed at another. Among its applications are: - Road warriors: synchronize files between laptop and home base This report describes the program in detail, including motivation, basic concepts, applications, and the program's interface.

Read the full technical report (PDF: 72.2 kB)

File Synchronization with Unison

Linux.com Keep your laptop and PC in Unison

SUSE LINUX 9.1 Administration Guide 16.4. Introduction to Unison

Perl

Reflect

reflect - A hard drive mirroring perl script.

Version: 1.0 Entered-date: July 20, 1995 Description: reflect is a perl script which will assure two directory structures are identical. It's intended purpose is for backing up directories to another hard drive. It can gzip the destination files and update files that have changed. Keywords: backup, reflect, mirror, hard drive Author: [email protected] (Rick Niles) Maintained-by: [email protected]

Win32

Software Download File Folder Synchronization Synchronizer Backup

When you work, even just occasionally, on multiple computers, you probably have to copy files from one device to the other. Although you could keep file modifications in your mind, there is a better way to apply your skills. Let Allway Sync take care of recent changes to your files. It looks for the latest version of a file, in specified folders, and copies it to the other folder, i.e. it synchronizes them. Unlike other file synchronization software which just copies file with the most recent file modification time, Allway Sync implements a sophisticated algorithm which does not depend on system clock accuracy. Allway Sync is fast, safe, stable and easy-to-use. All you need to do is to specify the local or network folders (directories) to be synchronized and the program does the rest. If your computers are not connected, use a removable drive to synchronize them. Free download from Shareware Connection - Allway Sync synchronizes local, network or removable files and folders. Fast, safe, stable, easy-to-use and FREE!

Dir Compare - Version 1.0 Published by Jeff Williams Platform Win 95/98/NT Dir Compare (17 KBytes)

Ever wanted to delete, copy, move, or make a list of duplicate files? Ever wanted to know which files were different sizes? Now you can with Dir Compare. And you can compare against as many directories as you wish!

Beyond Compare - Version 1.7c Published by Tim Thousand Platform Win 95/98/NT Beyond Compare (835 KBytes) A directory compare utility and a file compare utility wrapped in one. Synchronize files between laptop & PC, home & office, etc. Compare directory trees side-by-side with mismatches highlighted. Display text files side-by-side with changes highlighted. Great for merging changes tosource code. Supports minor editing, Delphi form files, and handles Unix format text files. Save favorite "sessions" for quick access.

Copyto - Version 2.14 Published by Kish Designs Platform Win 95/98/NT Copyto (346 KBytes)

A 32-bit file synchronization and backup utility for Windows. Use it to safely synchronize files between a desktop PC and a notebook PC, move files between the home and office with removable media, like ZIP or JAZ, or update multiple computers on a network, with the multiple folder settings. As you synchronize files, you can filter certain file types and exclude specified folders. You can display a preview window and check for disk space before you start the copying process. Launch CopyTo from an

IomegaDirect.com

Everyone wants to keep their files safe, but who wants to go through the hassle of creating a backup? Now, with Iomega Quik Sync 2 software, you can back up your files without any hassle. Every time you save a file to your hard drive or to a network drive, Quik Sync 2 software automatically makes a copy of that file on an Iomega Zip® or Jaz® drive and disk (software does not support ZipCD™ with MAC®). All you have to do is select folders for Quik Sync 2 software to monitor. The files within those folders are copied to the Iomega disk of your choice whenever they're saved. (IMPORTANT! This version of Quik Sync 2 only works with English versions of Microsoft® Windows® 95 / 98 / 2000 / NT® 4.x and Mac® OS 8.1 to 9.x)

Want to find out more about Iomega Quik Sync 2? Click here.

Click here to download your free 30 day evaluation copy of Iomega Quik Sync 2 software.Registration is $19.95

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Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 :  Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method  : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law

History:

Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds  : Larry Wall  : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOS :  Programming Languages History : PL/1 : Simula 67 : C : History of GCC development :  Scripting Languages : Perl history   : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history

Classic books:

The Peter Principle : Parkinson Law : 1984 : The Mythical Man-Month :  How to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Hater’s Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite

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The Last but not Least Technology is dominated by two types of people: those who understand what they do not manage and those who manage what they do not understand ~Archibald Putt. Ph.D

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Last modified: March 12, 2019