Forward vs Reverse incremental performance

[DCW]

Hello,

Are there any guidelines for the expected performance difference between forward incremental and reverse incremental backup jobs?
I'm trialing a reverse incremental job which seems to be running about 6-7 times as slow as my forward incrementals and wondering if this is the standard performance hit.

Thanks

[PetrM]

Hi Chris!

Rollback creation in reverse incremental mode results in higher I/O load on the target storage because Veeam performs 3 I/O operations for each data block: 2 write I/O + 1 read I/O.
Forward incremental requires just one I/O write operation for every block.

At first sight, I would say that the repository on which you perform these tests is much slower (almost 4x) on read.

You may want to have a look at this table to get more information about I/O impact on destination storage depending on backup chain mode.
This tool might be useful in some cases as well to simulate different chain modes and to test repository performance.
By the way, the similar issue is discussed in this thread.

Thanks!

[DCW]

Thanks Petr!