How to Determine Individual VMs Size Impact on Synthetic Fulls

[Lincoln44]

I'm trying to track down some concrete numbers for individual VMs space usage as part of a synthetic full. As far as I can tell, only the size of VMs in the incrementals are reported and for fulls I only ever see the whole backup size without any individual breakdown. Any idea if I am overlooking a report somewhere to find this info, or is it as simple as adding up the incrementals for that backup set?

[PTide]

Hi,

If you go into backup properties, you can see how much data has been stored into a backup file in total (Data size) and how much space the backup file actually occupies after compression. For incremental backup "Data size" value determines how much of new datablocks is contained in the backup.

Regarding 'adding up' incrementals - consider the following:

A full backup contains blocks A,B,C,D

Block B has changed to B1 on the VM

Incremental will contain block B1.

Block B1 has changed to B2 on the VM

The next incremental will contain B2

Block A has changed to A1 on the VM.

The 3rd incremental will contain block A1.

On the original VM: blocks A1 and B2 have changed to A2 and B3 respectively, and block E has been added

Synthetic full time: the resulting synthetic backup will contain A2,B3,C,D,E

That is, synthetic full data size is not a sum of all increments.

Currently it is not possible to see perVM size in a backup file in the UI, however you can check this report that gives a good estimate (see 'Backup Tasks' section).

P.S. I guess that you're not using per-VM backup chains, right?

Thanks!

[Lincoln44]

Thanks for the info. You are correct in that I am not using per-VM backup chains. I looked in to this option, but unfortunately enabling it would be at the sacrifice of data deduplication and space is already tight.

I'll take a look at that report some more and see what it can do, but the Backup Tasks section you mentioned looks like it's just a breakdown of a single incremental job if I'm not mistaken? I have the default reports emailed upon job completion and they seem to have a similar breakdown as that specific section. Not seeing how to get an estimate when it comes to the synthetic full with that info though, unless I am misunderstanding the report?

[PTide]

The report that I referenced contains "Successful Backup Jobs" section for a backup job that is called "Main Backup Job (Reverse Incremental)". The subsequent "Successful Backup Tasks" section is basically a breakdown for the job:

VM Name Job Name Start Time Stop Time Duration (HH:MM:SS) Avg Speed (MB/s) Total (GB) Processed (GB) Data Read (GB) Transferred (GB) Status

WIN8 Main Backup Job (Reverse Incremental) 11/27/2017 4:30:43 AM 11/27/2017 4:40:24 AM 0:09:40 16.35 160 119.59 5.17 1.96 Success
myDC Main Backup Job (Reverse Incremental) 11/27/2017 4:40:27 AM 11/27/2017 4:42:40 AM 0:02:12 27.95 260 69.1 0.94 0.28 Success
vCenter Main Backup Job (Reverse Incremental) 11/27/2017 4:42:41 AM 11/27/2017 4:47:49 AM 0:05:07 18.36 125 28.15 2.95 0.57 Success
MainServer Main Backup Job (Reverse Incremental) 11/27/2017 4:47:53 AM 11/27/2017 5:04:05 AM 0:16:11 38 120 39.46 29.5 0.61 Success

Thanks