Disk alignment with ESXi

[Timothy1]

Hi,

A colleague of mine was talking about boosting some storage performance by aligning the vmfs with the underlying storage and the upper vm disks. However the document he sent me described some fdisking in the service console. This already seems like a harsh thing to do but my question is, how can align the disk with ESXi. There is no real service console and using Tech mode is not really supported. Does anyone have experience with aligning disk in ESXi? Is it really necessary and/or will it help?

TIA

Timothy

[Troy_Clavell]

This white paper may be helpful if you haven't see it.

http://www.vmware.com/pdf/esx3_partition_align.pdf

[SuryaVMware · Accepted solution]

Starting from ESX 3.0 the disks are already alligened. So the ESX 3i

disks (VMFS volumes) are already aligned. Make sure your VM's disk are

alligned and you should be fine.

Doc listed by Troy should help you to determin on how to align the Guest OS disk. My advice would be just align the data disk not the OS disk.

-Surya

[Timothy1]

Ok thanks for the tips. Are they even aligned if they are not managed by vCenter (I imagine that having vCenter should not have any impact on disk alginment).

[SuryaVMware]

vCenter has nothing to do with VMFS disk alignment. If you add a datastore using a VI Client connected directly to the ESX server or through vCenter your disk will be aligned.

The only case you may endup with unalighed VMFS volumes would be if you partition the disk manual from the command line and set the partition type to 'fb' and format it as vmfs volume.

Hope this answers your question.

-Surya

[Timothy1]

thanks this really helped