VMware Cloud Community
FrostyatCBM
Enthusiast
Enthusiast

Advice -- migrating from VMFS3 to VMFS5

I have just started the process of migrating my datastores from VMFS3 to VMFS5 and am generally taking the following approach for each datastore:

* use Storage vMotion to move all VMs to another datastore

* delete the old VMFS3 datastore

* create the new VMFS5 datastore

* use Storage vMotion to move all VMs back again

I know that I could just upgrade them to VMFS5 however I believe that I would not have quite the full range of features of VMFS5 (e.g. sub-block size 64K) and my block sizes would range from 1MB to 8MB and I would prefer that I have them all identical "just because".

I've run into a small roadblock:  I have a VM that I use for backups and it has a couple of 2000GB virtual disks.  Each disk is in its own LUN.  When I browse the relevant datastores I can see that there is just a single VMDK file in the VM's folder.  To achieve my goal I was thinking that I could maybe detach that virtual disk from the VM, move it elsewhere, delete/recreate the datastore as VMFS5, then re-attach it to the VM.

Just wondering if there might be a different way of handling it?  Or should I just drop the idea of recreating all the datastores and just upgrade them to VMFS5 ... its such a quick process ... and moving everything off, recreating, and moving the data back again is rather laborious.

Reply
0 Kudos
3 Replies
memaad
Virtuoso
Virtuoso

Hi,

All the things that you said sounds good , only question will be moving of 2000GB disk from one datastore to another just for upgrading to VMFS 5.0, sinec thhis can take considerable about of time to move vmdk from one datastore to other. I think for this datastore which has 2000GB vmdk , just go ahead and upgrade vmfs version.

Regards

Mohammed

Mohammed | Mark it as helpful or correct if my suggestion is useful.
chriswahl
Virtuoso
Virtuoso

Your reasoning is solid. When at all possible, I advise to go with a plan to re-create the VMFS5 datastores from scratch. I've written on reasons why here:

http://wahlnetwork.com/2012/11/13/increasing-storage-vmotion-performance-with-unified-vmfs-block-siz...

Regarding the large VMs: since they most likely will not be migrating around in the future, and you basically have the "one big VM" design on them, I don't see a problem with doing a straight upgrade. Even the smaller sub-block size won't help you out much, since there's only a single VM worth of non VMDK files on them to fuss with.

VCDX #104 (DCV, NV) ஃ WahlNetwork.com ஃ @ChrisWahl ஃ Author, Networking for VMware Administrators
FrostyatCBM
Enthusiast
Enthusiast

Thank you both for your comments.  They have helped me resolve my approach.

For the smaller datastores I will move the VMs off, recreate datastores, then move the VMs back again.

For the larger datastores where I have the big 2000GB disks I will just convert them.

Thanks again,

Steve.

Reply
0 Kudos