Congratulations on the new XSIBACKUP-DC, it really is a major update of XSIBackup-Pro which in itself is pretty great!
I'm running some tests before migrating all the backup jobs and I have some questions:
- In XSIBackup-Pro the email contained some filesystem stats like the available diskspace before & after the backup.
Really useful when checking emails in the morning, would it be possible to include those stats again in the DC email template in a future update?
- I ran some tests with a single VM and with XSIBackup-Pro the data folder is 1.8GB in size and with DC & compression enabled it's 2.2GB.
Is there anything that can explain the size difference?
We will add more features rapidly before Christmas as branch 1.0 evolves.
DC version uses LZJB compression for licensing reasons as opposed to LZOP which is used by Pro. There aren't any licensing concerns in the case of Pro version as it calls the LZOP binary from a script on the command line, while in DC we are using the LZJB source code that you will find in the src folder.
Depending on the VM, and the layout of the data in the virtual disk, you may get a worse compression ratio than with LZOP, but that's only in the first round of the backup. As DC uses a smaller block size and the compression achieved by the deduplication is much higher than the regular data compression, as data grows and backups and restore points start to accumulate, the difference in plain data compression ratio will vanish.
So, if you compare plain data compression figures, you will see an average of 10% to 15% better compression ratio when using LZOP. If you compare the overall compression ratio after a number of backups, the difference will dilute so much that you won't notice when using the same block size and when usiing a smaller block size the compression ratio achieved by DC should be better.