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  • 1.  Estimate completion time for P2V

    Posted Oct 05, 2014 12:57 PM

    Hi experts,

    I'll be doing P2V migrations using the VMware standalone converter 5.5 tool for a couple of physical servers. Plan to install the converter tool on the source machine itself and convert to target vCenter server with ESXi hosts (all running 5.0) connected to EMC SAN using RAID10 datastores.

    what I want to know is - one of the physical servers has 500GB of total disk capacity (C,D and some SAN volumes) however the space utilized is at 140GB. If I convert using thin provisioning for destination disk type, I know the tool uses block based copying (uses file based copying if disk size is reduced) but will the tool copy only the real data (140GB) and is the time required for cloning based on 140GB or the 500GB total disk size of the source server. Cause if I estimate the transfer speed avg as 10MB/s it should take around 3-4 hours to copy only data (140GB) however if it does block based cloning of source server disks totaling 500GB (including empty space) then the time required (approx) could take a whopping 14 hours.....

    Question, does block based cloning using thin provisioning as destination disk type copy the entire source disk (including empty space) or does it only copy the used space / actual data??



  • 2.  RE: Estimate completion time for P2V

    Broadcom Employee
    Posted Oct 05, 2014 02:08 PM

    In any case - the empty space of disk is not copied.

    HTH



  • 3.  RE: Estimate completion time for P2V

    Posted Oct 06, 2014 05:41 AM

    Appreciate the reply but it's still not clear to me whether the estimated time for completion should be based off the total disk capacity or total size of data on source server. That's the most important thing here.

    Page 22 of the user guide says that choosing thick as destination type copies the entire source disk size to the destination, regardless of its used and free space and that for destinations that support thin provisioning through GUI, creates an expanding disk on the destination. For example, if the source disk size is 10GB, but only 3GB is used, the created  destination disk is 3GB but can expand to 10GB.

    So should my estimate for P2V completion be based on the total disk capacity (500GB) or the total used space (140GB) on the source server when using thin provisioning as destination disk type??



  • 4.  RE: Estimate completion time for P2V

    Broadcom Employee
    Posted Oct 06, 2014 06:42 AM

    The destination disk type is about how an ESX will handle disk, the thick disk will reserve all disk capacity while the thin disk will grow if necessary.

    You can predict your transfer based on used space on disk, however the speed of transfer depends on many different factors and can not be calculated precisely.

    From the other hand there is an incremental synchronization which will be useful in your case - the down time is minimized because initial sync will transfer 'base' data and incremental sync(s) will transffer only differences.

    HTH



  • 5.  RE: Estimate completion time for P2V

    Posted Oct 06, 2014 09:07 AM

    Hi,

    There are few factors you need to consider here.

    1) Total size of data on disk.

    2) Network usage.

    3) ESXi host performance.

    4) Storage performance.



  • 6.  RE: Estimate completion time for P2V

    Posted Oct 07, 2014 12:58 AM

    Thank you champs! Im aware of the other factors, just wanted to be clear about the disk cloning part which is one of the main factors impacting P2V completion time.