Best Practice for LUN & OS Disc

[Superwin]

We are now running short of space on our OS LUN (800gb) and i am not sure if it will be best to either

a:) extend the lun or

b:) Create a new seperate LUN and call this OS disc 2.

I have got some thoughts but wanted to see if anyone else has the same ideas.

Cheers

[AndreTheGiant]

Welcome to the community.

If you can extend the LUN from storage side, then you can simple use the grow feature of vSphere to increase also the VMFS datastore.

But also another LUN and another datastore could be a valid solution.

Andre

[a_p_]

Basically I would tend to option 2. However, this depends on your storage. If you have a storage with multiple controllers or a mirrored storage system, you could configure the LUNs in a way to distribute the load on the controllers/storage systems.

André

[Superwin]

Thanks Andre

If i have another LUN with another OS disc i presume i will have to be carefull which virtual machines use which

OS lun. So if i need to migrate virtual servers from one host to another will this cause issues?

Thanks

Paul

[a_p_]

With shared storage, you will present all LUNs to all ESXi hosts using the same LUN-ID. This way you can migrate the workload (vMotion) without issues.

André

[Superwin]

Yer we have an EVA 4400 with Dual FC controllers and i have got all this on a mirror in another building. (our DR site)

My gut feeling is to create a new LUN with a new OS disc. This is for a new project so it might be beneficial at a later stage.....i think

[Superwin]

ah i see, therefore if i move a server to another host, because the other host has already got a presentation of OS disk 1 and OS disk 2 vsphere will allow it to migrate. is that right?

Thanks Andre

[a_p_]

Just to make sure we are talking about the same thing. When you say "OS disk" do you actually refer to the "VMFS datastore"?

Regarding your question. Yes, you are right. If all the hosts can see the same LUNs with the same LUN-ID you can move the VM's without issues.

Assuming you run the production on one EVA and use the other one only as the mirror, configure the managing controller for the first LUN as "Controller A with Failback" and for the second LUN as "Controller B with Failback" to distribute the load between both controllers. When it comes to the presentation of the LUNs, use the "Assign LUN" buttotn to be able to select the same LUN-ID for each hosts!

André