DATTOBD: Block-Level Snapshots/Backups For Linux

[phoronix]

Phoronix: DATTOBD: Block-Level Snapshots/Backups For Linux

The Dattobd driver was open-sourced earlier this month by Datto Inc. The Datto Block Driver is for taking block-level snapshots and incremental backups...

http://www.phoronix.com/scan.php?page=news_item&px=Datto-Block-Linux-Driver

[rdnetto]

This is pretty interesting. It looks like they're storing the COW data to track the changes *within* the file system that is being snapshotted, which has the interesting side-effect of preventing it from being used with btrfs/ZFS.

I'm not entirely certain why it's necessary to explicitly jump between incremental and snapshot modes though - it seems as though that's the sort of thing the tool should do automatically. (Unless there's a use case I'm missing?)

It's also somewhat ironic that they recommend btrfs to be used to keep multiple versions of the image, rather than supporting that natively. My gut feeling is that it should be possible to support it natively if img-merge was able to generate (and then run) a diff, rather than doing both simultaneously. (This would be similar to how btrfs send/receive works.) But I haven't looked at the source, so maybe that's not viable.

[shamil.si]

Looks very similar to Linux Hot Copy. http://www.r1soft.com/free-tool-linux-hot-copy.