Change block size for VMFS datastore file system with a different block size

From the ESX/ESXi console:
Note: This procedure should not be performed on a local datastore on an ESX host where the operating system is located, as it may remove the Service Console privileged virtual machine which is located there.

  1. Storage vMotion, move, or delete the virtual machines located on the datastore you would like to recreate with a different block size.
  2. Log into the Local Tech Support Mode console of the ESX/ESXi host. For more information, see:
  3. Use the esxcfg-scsidevs command to obtain the disk identifier (mpx, naa, or eui) for the datastore you want to recreate:

    # esxcfg-scsidevs -m 

  4. Use vmkfstools to create a new VMFS datastore file system with a different block size over the existing one:

    # vmkfstools -C VMFS-type -b Block-Size -S Datastore-Name /vmfs/devices/disks/Disk-Identifier:Partition-Number 

    Example command to create a datastore called NewDatastore with an 8 MB block size:

    # vmkfstools -C vmfs3 -b 8m -S NewDatastore /vmfs/devices/disks/naa.60901234567890123456789012345678:1 

  5. Rescan from all other ESX hosts with the vmkfstools -V command.

Categorised as: Networking, Virtual Infrastructure, VMWare/ESX

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