Processing speed varies for VMs on the same LUN

[bc07]

I did some checking and calculation from last weekends full backups. The speed varies a lot ranging from 16MB/s to 40MB/s sometimes even when backing up from the same LUN. This speed is the real speed not the processing rate. With real speed I mean, actual used disk space in the VM (not the vmdk size) divided by the processing time minus 1minute.
Why is that? Differences at dedupe or compression? Unfortunately I can't say because they were all backed up in one job and I see the Dedpue/compression ratio only for the whole job.

[Gostev]

I am splitting this into the new topic, not to hi-jack the original thread. The difference is caused by whitespace (zeroed blocks) and duplicate blocks (already backed up by the same job). Both increase the VMDK processing rate because there is no need to read and write certain blocks. Thanks.