Typical Exchange snapshot schedules are something like full snapshots hourly, transaction logs on the half hour, rolling snapshots of the log luns (every minute or so), a daily backup that gets an integrity check (and often rolled off to tape). Most people are keeping 5-7 days, though larger implementations often keep 14-30 days worth of snapshots on disk. Provided they don’t go over 255 total snapshots per volume. Many of them also use Snapmirror for DR, and just pull to tape or run the integrity checks from the DR copy. Some pretty cool stuff.

Yes, one of the great benefits of Snap technology is being able to keep a system/database backup “in-ready” just in case it’s needed. I think, while we are only planning on putting the data to tape once a day, that we’ll probably go on a two-hour cycle between two different sets of virtual devices for added protection.