Changing Disk Cluster Size with VM-Converter

[Paulk99]

Morning all

We are likely going to be replacing our storage environment with one supplied by a new vendor.

Our current Vendor has a recommended Cluster size of 4k. So all our VMDKs are configured with a 4K cluster, size happy days.

The new vendor we are investigating however recommends 8k.

So I've been considering v2v`ing our server estate to the new platform, modifying the block size in the advanced features tab of VM-converter in the process giving us system's formatted with 8K blocks.

There is however an MS Requirement that the System drive remains at 4k (otherwise it wont power on). Its that pesky little 100Mb partition..

Now comes the rub;

The 100mb System partition, forms part of the first Disk ( C:\ ). If I P2V the first disk with a cluster size of 8k I of course get a non-bootable server. 

When in fact I actually want to v2v Disk 1 ( C:\ ). As 8kb but leave the little 100Mb system partition alone with its default of 4kb, However because they form part of the same disk, and converter seems to work at the disk level and not the Partition level, Converter just wants to do them all which is a problem.

Any ideas on how to accomplish the above...

Cheers

P

[Rosen Tomov]

4K and 8K are about *cluster* size, not the sector size or other size.

And cluster size is about volumes, not for disks nor for partitions, and could be mixed for different volumes on same disk.

So go ahead and test if boot process will succeed with system volume on 4K and active volume on 8K.

HTH

[Paulk99]

Sure they may indeed be mixed, this is exactly what I'm trying to achieve.

But changing the cluster size for a disk during the v2v adjusts the cluster size for all associated volumes within that disk.

Not good when a cluster size above 4k for the system partition will render a system un-bootable.

P

[Rosen Tomov]

This seems to be Windows issue, but you can convert with default cluster size and after that change the cluster size with some tool like minitool.

HTH

[Paulk99]

Hi there mate

Sorry for the delay we are in testing at the mo and I haven't been able to dedicate much time to this.

Any ways I got it cracked, I was testing on a 2k3 box where something like minitool would be essential to complete the cluster size change of the C:\ for the reasons given.

But when v2v-ing (with VM converter) a 2k8 or 2012 box the system partition is presented to the converter as an independent drive and therefore can be left @ 4k while the C:\ D:\ etc can be adjusted as required using the advanced settings.

So in the end you have a system with drives using the required cluster size and a bootable system... :smileyhappy:

just for future reference should it prove useful to anyone.

P