Forum Discussion

Pierre_J's avatar
Level 4
6 years ago

How to determine daily change rate

Hello All,

It seems odd but I have difficulties determining the daily change rate of the data I am backing up.

We write to a dedup device (Data Domain) so from that side it is hard to get some figures.
We use Accelerator in many policies and that makes a full backup of VM's even when an incremental is scheduled.
With Oracle, Exchange and Windows backups I can see a difference in Kb written between full and incremental backups but not for VM's.

So, is there a way to figure this out for VM backups?

Any help appreciated,
Kind regards, Pierre.

  • PIerre

    Read the section in the VMware admin guide chapter 9 - "About Reporting the amount of Accelerator backup data that was transferred over the network".
    There are three commands you can use bpdbjobs, bpimagelist and bpclimagelist.

    With any of these you can cobble together a script to create the output you need.


  • Hi Pierre

    The numbers reported are the accelerated numbers - so will be showing the change blocks from the VM itself. This is the data transferred from the VM backup host to the media server (which may be the same machine). 

    There may be additional information in the job details that indicate the amount of deduplicated data sent to the Data Domain (although I'm not 100% sure this is reported for DD, like it is for an MSDP storage unit).

    So for eaxmple you have a 100GB VM. For an accelerated backup (with say 10% change rate), 10GB would be rquired to be read by the media server. Of this 10GB, DDBoost may not require some of this as the data already exists in the DD (this is the deduplication performance). 

    The bpimagelist command (and others mentioned) will show the 10GB value of the acceleratoed backup, NOT the amount of data sent to the DD.


8 Replies

  • Hi Pierre

    You should be able to examine the job details in the GUI and look for a line near the end of the job showing a summary of the accelerator performance. It will look something like this:

    7/27/2012 4:43:07 AM - Info bpbkar32(pid=4636) accelerator sent 74764288 bytes out of 5953504256 bytes to server, optimization 98.7%

    There may be additional information on this line regarding the deduplication performance as well (I don't recall if this is shown with Data Domain backups). 

    From the above - the amount of data backed up was 75Mb or 1.3% of the total size of the VM, so the change rate for the VM for that backup was 1.3%.


    • Pierre_J's avatar
      Level 4

      Hey David,

      I've seen that line in Job Details and figured that this was probably usefull but didn't know for sure.

      However this line is 'hidden' in the Job Details, is there a way to extract this from all (several thousands) jobs in a day?

      • Krutons's avatar

        You could create a custom report that pulls 'Job Size' and 'Accelerator Data Sent' along with client name/policy/schedule and any other info you want.