Hi folks,
This is half a sob story to warn others who might try this, and half an open question about VM performance templating.
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I recently got burned doing windows V2V on a 2K8R2 VM with Converter 5, as I had been reading about ESXi5 and the 8K clusters on VMFS5 and there might be speed improvements aligning VM filesystems. So I thought why not resize both the boot partition and the main OS partition of a single disk VM to 8K cluster size? The task finishes so things seem good, then I boot to check the VM. Well, that conversion definitely broke the OS...
The short version is that the bootloader partition MUST be 4K cluster sized (less might work they say, bigger definitely does not work).
http://support.microsoft.com/kb/2272294
So for the 7/2008 R2 family (and likely Vista/2008 and XP/2003), it seems the bootloader should reside in the first partition of the first detected disk in a 4K cluster size partition formated to NTFS.
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So the question is, regarding the performance tweaking via block alignment (and potentially some gains via SAN deduplication), what is the consensus for partition formating for a single disk VM, and a multi-disk VM? Main aim is VMFS5 on ESXi 5U1, but comments on VMFS3 and ESXi 4.1U2 are welcome.
My impression for a single disk windows VM would be
DIsk 1
1. 4K cluster NTFS boot partition for boot loader (100MB minimum, maybe up to roughly the size of the OS page file +100MB, max?)
2. NTFS main OS install (8K cluster or 128K cluster?)
3+ DATA (match to workload?)
Does GPT partitioning change the recommendations?
For a multi disk VM, I have read that putting the page file on a FAT32 partition can boost speed, so separate that out?
Disk 1
1. 4K cluster NTFS boot partition for bootloader (100MB minimum, max?)
Disk 2
1. FAT32 partition for OS page file only
(4K? 8K? 128K?)
(Match the recommended OS page file size, which is 1.5xRAM, or go straight to 4K recommended limit of 4GB?)
Disk 3
1. NTFS main OS install (8K? 128K?)
Disk 4+
1. DATA
(8K? 128K? needs to account for workload/average file size)
(what about other filesystems? Say, if you were using Ext2IFS to access Ext2 or Ext3 filesystems on Windows?)
