Allocating 2TB to a VM - 2 Questions

[samuk]

Hi,

We are using ESX 4.1 - with SAN Storage.

I need to create a VM, that has a (D) data drive of 2TB -

Is this the correct way of doing this?

• Create the VM - OS Disk on an existing data store (40GB)
• Create a Datastore 2TB in size -
• Create a disk 2TB on the new Datastore

Will i run into any limitations when backing up using Veeam or snapshots?

Second Question:

If i have a 2TB LUN allocated to a VM, and i need to make this Lun bigger - would i

• Create a second DataStore
• Convert the cuurent vm disk to Dynamic
• Add new Disk to VM, and extend Dynamic disk

Thanks

[a_p_]

For the first question the steps are ok. However, the LUN size must not exceed 2TB minus 512 Bytes and the maximum virtual disk size - in order to be able to use snapshots - is 2,032GB.

Regarding the second question. I'm no friend of dynamic disks (although this should work), but would rather consider to split the user data and present different shares to two separate virtual disks.

Btw. with vSphere 5 both limitations are gone. Starting with vSphere 5.0 the maximum LUN/datastore size is 64TB and starting with ESXi 5.5 the max. virtual disk size is ~62TB.

André

[samuk]

So if i were to go to Vsphere 5.5, i can create a say 64TB Datastore, can i create a vdisk larger then 2TB? is this a limit of Windows?

[a_p_]

There are actually two things to consider. With vSphere 5.5 (vCenter Server is required!) it is possible to create virtual disks larger than 2TB (i.e. up to 62TB). You also have to make sure the guest OS as well as e.g. your backup application support disk sizes larger than 2TB.

André

[samuk]

we have vcenter server - backup software is Veeam backup.

also going back to Question 1

If i create a datastore of 2TB and a vdisk 2TB - 512bytes..

what happens if i create a snapshot - and it starts to grow? would i not kill the space \ server - can i force the the snapshot file to go on another datastore?

[vMariaL]

a.p. wrote:

There are actually two things to consider. With vSphere 5.5 (vCenter Server is required!) it is possible to create virtual disks larger than 2TB (i.e. up to 62TB). You also have to make sure the guest OS as well as e.g. your backup application support disk sizes larger than 2TB.

André

Just a quick note - Veeam Backup & Replication supports VMware vSphere 5.1 and older versions. We are working with VMware to deliver support for vSphere 5.5. While support was not available at release of vSphere 5.5, Veeam has a history of supporting the latest platforms in a timely manner and we will communicate support timeline to customers as soon as it is available.

----

Veeam Community Manager

[vMariaL]

samuk wrote:

we have vcenter server - backup software is Veeam backup.

also going back to Question 1

If i create a datastore of 2TB and a vdisk 2TB - 512bytes..

what happens if i create a snapshot - and it starts to grow? would i not kill the space \ server - can i force the the snapshot file to go on another datastore?

Hi samuk, thank you for chosing Veeam! Answering your question, this discusssion on Veeam Community Forums might be helpful - Snapshot Size 2TB.

----

Veeam Community Manager

[TomHowarth · Accepted solution]

As Andre correctly states,  you cannot actually have a 2TB disk, it is 2032GB.   dynamic disks or LVM's in Linux, could be used, but a much better and sensible way would be to look at how your data is organised and consider splitting it into smaller blocks of data.

That said, considering that vSphere 4.1 is end of life you really should be looking at updating to vSphere 5.5.  this upgrade would give you the ability to grow your disks above 2TB.

but you will also need to consider the limitations outlined in this KB article