Converting from Thin to Thick provisioned disk

[meolav]

I currently have 3 windows servers (Windows 2008 R2) operating on a single ESXI 4 host. The ESX host currently has 2 x 300GB configured as in RAID 1 and 3 x 500GB configured in RAID 5. Both are local datastore to the ESXi host. hypervisor is installed on the RAID 1 drives.

The 3 vm guests have system partitons set at 70GB however vmware sees them as thin provisioned. All system drives are on the RAID 1 drives.I want to convert them to thick provisioned. (there one AD server, one application server and one files server configured)

Current ESXi host and VM guests are in a test environment.

Is it best to turn off the guests, vmotion the datastore from the RAID1 datastore to the RAID 5 datastore and converting to thick provisioned in the same process. Then vmotioning them back.. There is over 500GB available on the RAID 5 drives.

or

Should I just shut down the vm guest and explore the datastore, find the VMDK files and inflate.

Are both methods OK, or should one method be used over the other.

Thanks for any advice that you can provide.

[meolav]

Forgot to ask, whichever method used, will there be any problems afterwoods wil disk defragmentations. How can they be rectified?

[a_p_]

1. Since there is an easy way now with the "Inflate" I would prefer this over conversion or migration. Conversion as well as migration will take longer and conversion will most likely generate a new UUID and MAC address for the VM.

2. There is no way to defragment a VMFS file system. Since the blocks are usually large, disk fragmentation should not be a real issue on VMFS.

I guess you are aware that a 3 disk RAID5 is one of the slowest RAID configurations that can be set up. Due to the checksum of each stripe, each write operation on a RAID5 has to be done to 2 disks (data + checksum). This means no other write operation can be done to the remaining disk. With e.g. 4 disks, the RAID controller could write to the remaining two disks at the same time.

André