I can tell you a little about Windows VSS snapshots compared to ZFS ones, since one of the main reasons I'm so interested in ZFS is because windows snapshots are so useless.
For windows VSS: * You have OS overhead for taking the snapshot, as opposed to it being instantaneous for ZFS. Microsoft actually recommend the snapshots are stored on a separate disk. * You have to reserve space in advance for them, so if you guess wrong you're out of luck. * Microsoft's snapshots can have one schedule. They support hourly, daily or weekly snapshots, but you can only pick one period. * You are limited to 64 snapshots. So if you want hourly snapshots of your data, you're not even going to have 3 days worth of backups. If you can live with daily backups you can manage 2 months worth. When you compare that to Tim's excellent auto backup service it makes VSS look like a joke. While ZFS doesn't actually limit how many snapshots you keep, with just 90 you can run: 8x 15 minute snapshots 48x hourly snapshots 14x daily snapshots 8x weekly snapshots 12x monthly snapshots So you have snapshots being taken *far* more regularly than VSS can manage, and they go back a full year with considerable overlap between the different periods. -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
