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July 12, 2011


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Jon Kohler

What is left out during the upgrade from VMFS3 to VMFS5?

Also, what happens if you have over 1MB blocks on VMFS3 now?

As I am not familiar with the SCSI UNMAP command, are there any arrays that will not support this (on the EMC side)?



Good info, can you expand on the VMFS 3 to VMFS 5 upgrade and not getting all the goodness?


From what I saw, if you upgrade a VMFS3 vol to a VMFS5 vol, the original block size remains the same.

Rickard Nobel

>Also, what happens if you have over 1MB blocks on VMFS3 now?

From my understanding, the old blocksize will be left if doing an upgrade.

Paul Henry

What is left out when you upgrade?

VMFS-5 upgraded from VMFS-3 continues to use the previous file block size which may be larger than the unified 1MB file block size.
VMFS-5 upgraded from VMFS-3 continues to use 64KB sub-blocks and not new 8K sub-blocks.
VMFS-5 upgraded from VMFS-3 continues to have a file limit of 30720 rather than new file limit of > 100000 for newly created VMFS-5.
VMFS-5 upgraded from VMFS-3 continues to use MBR (Master Boot Record) partition type; when the VMFS-5 volume is grown above 2TB, it automatically & seamlessly switches from MBR to GPT (GUID Partition Table) with no impact to the running VMs.
VMFS-5 upgraded from VMFS-3 continue to have its partition starting on sector 128; newly created VMFS5 partitions will have their partition starting at sector 2048.




It would have been nice if they'd addressed the block misalignement bug for various Oses. Oh well, maybe in 2020.

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