What you will learn from this tip: Uses for snapshots that go far beyond cleaning up after your users; plus, a few things to watch out for when using this technology.
The most common use for snapshots is quick, easy restores of accidentally erased or corrupted data. However, snapshots can be used for a lot more than simply fixing users' mistakes.
Basically, any time you need a copy of the data stored on a logical device, you should consider snapshots. Two places where snapshots can help storage professionals is resource consolidation and data migration. By using snapshots, you can easily move data to new hardware, whether for the purpose of replacing the existing hardware, rearranging the way data is stored, or consolidating several devices onto one.
The use of snapshots extends well beyond storage administration. For example, if users need a copy of a data set for training or an application like data mining, a snapshot can provide it with minimum fuss and bother. Snapshots are ideal for developers who need real data sets. Because it's so easy to get a copy of the actual data, developers can get a better sense of how their creations will perform in production. For storage specialists, the advantage of snapshots in these cases is that they offer a fast way to deal with users' requirements.
Just remember it is possible to have too much of a good thing. While some snapshot-creating software like Windows XP will automatically delete old snapshots, other applications don't. Worse, not all of them fail gracefully when they've filled their allotted disk space. If you have an application that automatically deletes old snapshots, set the parameters appropriately for your enterprise. If you have applications that don't automatically clean house, then you should monitor them and remove old files as appropriate.
For more information:
Tip: Should you use snapshots for end-user file recovery?
Crash Course: Snapshots
Advice: How and where to use snapshot technology
About the author: Rick Cook has been writing about mass storage since the days when the term meant an 80 K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.
