On Tue, 13 Oct 2009, Pasi Kärkkäinen wrote:
Hmm.. what kind of problems do you have with snapshots?
Let's see
They take up 16MB of space regardless of the amount of data that changes. A single bit changes and 16MB is taken up. This is not tunable.
Mounting a snapshot requires the generation of a new UUID for the file system in order to be able to use it. Perhaps this is a XFS limitation, but unlike ZFS they aren't immediately available. We need to perform this action extensively to backup file systems and allow for quick data recovery.
There is no GNU/Linux interface to automating the snapshot process. Sure there is a telnet interface but it changes from version to version. I know because I've spoken with engineers to discuss this issue. I wrote software to talk to the EQL using the interface. There are talks of an SDK for developers but nothing has materialized.
Don't get me wrong, it's a great device for cheap storage compared to competitors but there are obvious limitations that you need to address in your requirements if you intend to deploy it.