VMFS 5 Partition Alignment

[firestartah]

Hi

Am I right in thinking that now with VMFS 5 using the unified 1MB block size and as long as you create the datastore via the viclient there is no need to align the partitions like you used to have to in ESX3,4?

Thanks

Gregg

[harrygunter]

I thought from esx4 onwards if you formatted through the viclient they were automatically aligned, only in 3 they were not.

Just checked the http://www.vmware.com/pdf/Perf_Best_Practices_vSphere4.0.pdf

The alignment of your file system partitions can impact performance. VMware makes the following

recommendations for VMFS partitions:

 

Like other disk-based file systems, VMFS suffers a penalty when the partition is unaligned. Using the

vSphere Client to create VMFS partitions avoids this problem since it automatically aligns the

partitions along the 64KB boundary.

[aravinds3107]

Alignment are taken  when VMFS5 are created

New Starting Sector

VMFS-5 partitions will now have a starting sector of 2048. This is different from VMFS-3 which had a starting sector of 128. Moving to a starting sector of 2048 helps avoid alignment issues

[cmcminn]

VMFS 5 is based on GPT and not MBR, no alignment issues by default...  The O/S can potentially still have issues if they are using MBR.  2008 and Win7 do not have alignment issues for example...  Most storage vendors have a solution around alignment and taking care of it fo you.  Some native, some boltons.

[firestartah]

:smileyhappy: Thanks, just what i thought.

[Duncan Epping]

Cormac Hogan wrote an article about this:

http://blogs.vmware.com/vsphere/2011/08/vsphere-50-storage-features-part-7-gpt.html