File synchronization

<h2 id="common-features">Common features</h2>
<p>Common features of file synchronization systems include:
</p>
<ul><li><a href="/facts/Encryption/16q29Fdv">Encryption</a> for <a href="/facts/Internet_security/LeTm8Wx4">security</a>, especially when synchronizing across the <a href="/facts/Internet/Xw1rVvJU">Internet</a>.</li>
<li><a href="/facts/Data_compression/gMFuY4FT">Compressing</a> any data sent across a network.</li>
<li><i>Conflict detection</i> where a file has been modified on both sources, as opposed to where it has only been modified on one. Undetected conflicts can lead to overwriting copies of the file with the most recent version, causing data loss. For conflict detection, the synchronization software needs to keep a database of the synchronized files. Distributed conflict detection can be achieved by <a href="/facts/Version_vector/U96FfE1p">version vectors</a>.</li>
<li><i>Open Files Support</i> ensures data integrity when copying data or application files that are in-use or database files that are exclusively <a href="/facts/File_locking/QektVCQs">locked</a>.</li>
<li>Specific support for using an intermediate storage device, such as a removable flash disc, to synchronize two machines. Most synchronizing programs can be used in this way, but providing specific support for this can reduce the amount of data stored on a device.</li>
<li>The ability to preview any changes before they are made.</li>
<li>The ability to view differences in individual files.</li>
<li>Backup between operating systems and transfer between network computers.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a></li>
<li>Ability to edit or use files on multiple computers or operating systems.</li></ul>
<h2 id="comparison-to-shared-file-access">Comparison to shared file access</h2>
<p class="note">This section is an excerpt from <a href="/facts/Shared_resource/tmLvfkwR">Shared resource § Comparison to file synchronization</a>.[<a href="https://en.wikipedia.org/w/index.php?title=Shared_resource&action=edit">edit</a>]</p>
Shared file access involves but should not be confused with file synchronization and other information synchronization. Internet-based information synchronization may, for example, use the <a href="/facts/SyncML/mGTNutju">SyncML</a> language. Shared file access is based on server-side pushing of folder information, and is normally used over an "always on" <a href="/facts/Internet_socket/r1ldfkb5">Internet socket</a>. File synchronization allows the user to be offline from time to time and is normally based on an agent software that polls synchronized machines at reconnect, and sometimes repeatedly with a certain time interval, to discover differences. Modern operating systems often include a local <a href="/facts/Web_cache/DqIBcWem">cache</a> of remote files, allowing offline access and synchronization when reconnected.
<h2 id="possible-security-concerns">Possible security concerns</h2>
<p>Consumer-grade file synchronization solutions are popular, however for business use, they create a concern of allowing corporate information to sprawl to unmanaged devices and cloud services which are uncontrolled by the organization.
</p><p>When using cloud services, data privacy risks can be mitigated by using a file synchronization solution that features <a href="/facts/End-to-end_encryption/e1MwRzEU">end-to-end encryption</a> instead of simple transport (<a href="/facts/HTTPS/MSWYz4zo">HTTPS</a>) or at-rest encryption.
</p>
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Backup_software/PeJBHS6L">Backup software</a></li>
<li><a href="/facts/Comparison_of_file_synchronization_software/ChgSQflv">Comparison of file synchronization software</a></li>
<li><a href="/facts/Comparison_of_online_backup_services/jtHfHd31">Comparison of online backup services</a></li>
<li><a href="/facts/Data_comparison/rCRIKwFM">Data comparison</a></li>
<li><a href="/facts/Data_synchronization/rjQV9RkX">Data synchronization</a></li>
<li><a href="/facts/Web_mirror/n9mBsW8j">Mirror (computing)</a></li>
<li><a href="/facts/Remote_backup_service/nT88cekN">Remote backup service</a></li>
<li><a href="/facts/Shared_file_access/tmLvfkwR">Shared file access</a></li>
<li><a href="/facts/List_of_backup_software/kr0AFm1y">List of backup software</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>A. Tridgell (February 1999). "Efficient algorithms for sorting and synchronization" (PDF). PhD thesis. The Australian National University. <a href="/wiki/Andrew_Tridgell" target="_blank">/wiki/Andrew_Tridgell</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Pierce, Benjamin (2009). "Unison File Synchronizer. User Manual and Reference Guide". Retrieved 27 January 2014. <a href="/wiki/Benjamin_C._Pierce" target="_blank">/wiki/Benjamin_C._Pierce</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>"Why Should You Backup Your Mac to a Windows (OS based) Computer?". Wei-Soft. Archived from the original on 2 December 2014. Retrieved 23 November 2014. <a href="https://web.archive.org/web/20141202010312/http://www.backupitnow.com/why-should-you-back-up-your-mac-to-a-windows-os-based-computer/" target="_blank">https://web.archive.org/web/20141202010312/http://www.backupitnow.com/why-should-you-back-up-your-mac-to-a-windows-os-based-computer/</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
</ol>

File synchronization open-in-new

File synchronization