vSAN1

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  • 1.  Add vSAN capacity

    Posted 25 days ago

    Hello,

    We have 2 disk group on vSAN "Cluster with 2 ESXi":

    The first disk group : 6 disks with a capacity of 894.25 GB (Dell PMT4X 960GB SATA 6GBPS 2.5" SSD MZ7LH960HAJR0D3) and 1 cache disk of 745.21GB.

    the second disk group : 2 disks with a capacity of 1.75TB (DELL 33R2T, 1.92TB, 2.5", 6Gbit/s) and 1 cache disk of 745.21GB.

    Current vSAN storage utilization is 74%.

    We'd like to increase the vsan's storage capacity, and to do so we'll have to replace some disks as we don't have any slots available for new disks.

    We've ordered 4 x 1.92TB disks to add (Dell Enterprise 086DD / Samsung PM1633a MZILS1T9HEJH0D3 2.5in SFF 1.92TB SSD 12Gb/S SAS SSD), 2 disks per ESXi.

    We have come up with two scenarios:

    The first: remove 2 x 894.25 GB disks from the first disk group and add the 2 new disks to the same disk group.

    The second: remove 2 x 894.25 GB disks from the first disk group and add the 2 new disks to the second disk group.

    We want to do scenario 2, in this case can we put disks with different capacities and speeds "12GB/6GB" in the same disk group?

    BR



  • 2.  RE: Add vSAN capacity

    Posted 25 days ago

    Hello,

    I think you will have a problem with the disk space. When I upgraded the disks I put the esxi in maintenance mode with full data migration. This will not be possible with the amount of disk space available. Also, based on the documentation it is not recommended to mix disks with different speeds and capacity. You will encounter problems.




  • 3.  RE: Add vSAN capacity
    Best Answer

    Posted 25 days ago

    We support both combinations, so it is up to you what you want to do. Do note, as mentioned the performance of these devices is different, it will not lead to problems, but could lead to a difference in performance. Chances are slim. anyone will ever notice, but it is always a possibility.

    Personally I would probably remove 2x 960GB and add the two devices to the second diskgroup, as from a capacity perspective that diskgroup makes mores sense to me as it aligns better.




  • 4.  RE: Add vSAN capacity

    Posted 25 days ago

    Hello,

    Thank you very much for your reply.

    As we are already at 75% vSAN capacity utilization, what is the best way to replace the disks :

    1- Remove the 960 GB disk with the "ensure accessibility" option and put the new disk directly ( 1 disk at a time per ESXi).

    2- Remove the 960 GB disk with the "full data migration" function, wait for the migration to finish and insert the new disk (1 disk at a time per ESXi).

    BR




  • 5.  RE: Add vSAN capacity

    Posted 23 days ago

    That is indeed a good option, also, I would force a repair when you add the first disk back and wait for it to complete syncing.