2TB limit on VMWare

[penfold]

I need to create a disk bigger than 2TB on a VM but when I have tried to allocate it I can't go above 2TB in VMWare. I have read that there was a 2TB limitation on creating vmdk files but I thought I could do it if the datastore was VMFS5 (which it is)? Am I just reading it wrong and will I have to create multiple disks in VMWare and then use the OS to create a larger than 2TB volume?

[howartp]

I need to create a disk bigger than 2TB on a VM but when I have tried to allocate it I can't go above 2TB in VMWare. I have read that there was a 2TB limitation on creating vmdk files but I thought I could do it if the datastore was VMFS5 (which it is)? Am I just reading it wrong and will I have to create multiple disks in VMWare and then use the OS to create a larger than 2TB volume?

What version of vSphere are you on?

 

IF I remember my VMware ICM training (Oct half term) correctly there was a change in VMDK size limits between 5.0, 5.1 and 5.5.

 

That's just from recall though, so might be wrong.

 

Peter

[penfold]

Vsphere is 5.1. Just to clarify that I am trying to allocate a disk onto a VM which is where I am hitting the 2 TB limit. As I need more in Windows I'm just wondering if this limit has been removed (or increased) in VMWare to more then 2TB or if this is the limit, what is the best way to get a 10TB (for example) disk in a Windows VM.

[jamesb]

This might help: VMware KB: Support for virtual machine disks larger than 2 TB in VMware ESXi 5.5

[tmcd35]

What version of Windows? I've got a couple of ideas...

 

• Create 5x 2Tb VMDKs and then use Software RAID-0 in Windows to combine them into one drive?
  
• Don't use VMDK's, pass thru a physical 10Tb Lun directly to the VM in question?
  

[howartp]

IF I remember my VMware ICM training (Oct half term) correctly there was a change in VMDK size limits between 5.0, 5.1 and 5.5.

This might help: VMware KB: Support for virtual machine disks larger than 2 TB in VMware ESXi 5.5

Ooh, I must have been paying attention at some point then!

[teejay]

You have two options, either upgrade to VMWare 5.5 which supports volumes up to 62TB or create a bunch of 2Tb drives and use software raid.

Edit: I'd avoid pass through to a physical disk, you lose a load of features that you get with virtual disks.

Edited November 20, 2014 by teejay

[penfold]

@jamesb - I had skim read that article but I just realised I never tried the webclient - if I do I get an error that the file size is larger than what is currently support on the datastore which suggests to me that I can't create a larger than 2 TB disk with our existing setup.

@tmcd35 - Windows 2012 I wanted to keep the disks on Windows so I could manage them within the server rather than having to into Vmware to manage the size of the disk. The reason being is that we currently allocate as little as possible to our VM's currently and then increase disk size as it becomes necessary. The reason we do this is because we had over allocated space for some servers and it was a pain to try and claim it back.

[penfold]

Am I right in thinking although our datastores are of the correct format - VMFS-5 we need to upgrade our Hosts in order to be able to take advantage of the benefits?

[jamesb]

Seems only ESXi 5.5 can support it, so you may need to upgrade depending on your current setup.

[penfold]

Jamesb - seems that way. We will be looking to upgrade when we can but for the meantime we are going to put a workaround in place. Namely keeping data to less than 2TB until we can set everything up properly.

[DMcCoy]

Are you using the free or commercial version? If you are using the commercial version you will not be able to manage the latest hardware version for the VMs with the vSphere client, you can only do it via the web interface or vCenter. Both of which need a commercial license.

[Ergo_Computing_IS_Support]

Hello,

I can confirm that for virtual disks > 2TB, both VMFS5 and ESXi 5.5 or later are required.

It also worth mentioning that upgrading VMFS3 datastores to VMFS5, doesn't alter the block size so if possible I'd recommend creating VMFS5 datastores from scratch to get the full benefits and features.

Additionally, it might be worth considering the benefits of Windows Server 2012 and the inbuilt deduplication. By enabling deduplication on the volume you can achieve some quite impressive storage reductions (depending on the type of data) and as a result you may not need to exceed the 2 TB limit.

 

That being said, VMware ESXi upgrades can be straight forward and non-disruptive if you have a clustered HA environment.

[penfold]

Hello,

I can confirm that for virtual disks > 2TB, both VMFS5 and ESXi 5.5 or later are required.

It also worth mentioning that upgrading VMFS3 datastores to VMFS5, doesn't alter the block size so if possible I'd recommend creating VMFS5 datastores from scratch to get the full benefits and features.

Additionally, it might be worth considering the benefits of Windows Server 2012 and the inbuilt deduplication. By enabling deduplication on the volume you can achieve some quite impressive storage reductions (depending on the type of data) and as a result you may not need to exceed the 2 TB limit.

 

That being said, VMware ESXi upgrades can be straight forward and non-disruptive if you have a clustered HA environment.

 

We were trying to move our data onto a single volume to apply dedup as we have seen some impressive results on our existing data which is spread across multiple disks at present. We were hoping to combine that into one area to get maximum results. We are going to schedule in an upgrade for our ESXI hosts.

@DMcCoy - commercial and that was the reason we held off upgrading in the past as we preferred the client over the web client. We'll just have to get used to the web client.