It’s new, and it’s good :-)
- VMFS-5 increases limits (without increasing extents) to 64TB.
- It enables 2TB+ RDMs.
- It uses a common allocation size of 1MB.
- It increases the small block allocations available for total use.
- It is a dependency for SCSI UNMAP
- It uses the VAAI HW accelerated locking more extensively.
A couple things that it doesn’t do:
- Increase the maximum LUN counts. Although frankly, with the fact that people should be using larger datastores with VAAI and VMFS-5, that should help with this.
- While it can non-disruptively be upgraded from VMFS-3 to VMFS-5 – this doesn’t net you all the goodness. IMO, if it were my environment – I would tend to create new datastores and svmotion. If I were large, I would still do it that way – but would do it programmatically.
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)?
Thanks,
@JonKohler
Posted by: Jon Kohler | July 12, 2011 at 11:28 PM
Good info, can you expand on the VMFS 3 to VMFS 5 upgrade and not getting all the goodness?
Posted by: Mtellin | July 13, 2011 at 03:27 PM
From what I saw, if you upgrade a VMFS3 vol to a VMFS5 vol, the original block size remains the same.
Posted by: eprich | July 14, 2011 at 11:16 AM
>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.
Posted by: Rickard Nobel | July 15, 2011 at 06:12 AM
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.
Best;
Paul
Posted by: Paul Henry | July 19, 2011 at 09:32 PM
It would have been nice if they'd addressed the block misalignement bug for various Oses. Oh well, maybe in 2020.
Posted by: nipester | December 25, 2011 at 12:51 AM