LUN larger than 2TB question.

[lgardian]

Presently I've a NetApp FAS2040A connected thru HBA. I created the 8TB LUN on the appliance and presented it to ESXi, but the ESXi has a limit on the VMFS of 2TB. I need to present a 8TB LUN to VM running a Win 2008 R2. What is the best way to do it without loosing too much performance and risking data loss. Some of the ideas of mine are as follows:

1) Create 4x 2TB VMFS LUNs and use dynamic disk in Windows to create a 8TB partition

2) Create 2TB LUN and use ESXi extents to bring that volume to 8TB

3) Get a license for CIFS and create the 8TB on the appliance

I'm fearly new to the ESXi so please bare with me. I'm looking for any better suggestions or ups and downs on the above scenarios.

Thank you for your help.

[vmroyale]

Hello.

4) Use the Microsoft iSCSI Initiator in the Win 2008 R2 server and access the LUN that way.

Good Luck!

[Dave_Mishchenko · Accepted solution]

Even if you create a datastore larger than 2 TB your virtual disks are still limited to 2 TB.  If you need to present 8 TB to the VM then your best option would be to configure the VM to connect directly to the 8 TB LUN using the MS software iSCSI initiator.

[Troy_Clavell]

as others suggested an iSCSI initiator is the way to go... However, that big of a volume in Windows, with possibly millions of files, performance may indeed be your bottleneck.

I would be inclined to use multiple smaller volumes within the OS instead of one big huge one.

[lgardian]

What happens when Windows fails, get corrupted etc. Does the LUN stays intact, is there a possibility of loosing the data, can I remount that LUN to a new Windows installation?

[lgardian]

And just to clarify the HBA is Fibre Channel.

[Troy_Clavell]

corrupted data is corruped data... Assuming the data doesn't get corrupted, yes, you can mount it to another guest.

[DSTAVERT]

Anything wrong with using the Netapp to share files directly with CIFS?

[lgardian]

Since I was not specific in my first post (my apologies) can I assume that Microsoft iSCSI Initiator won't work in my setup because the appliance is connected thru FC?

And no there is nothing wrong with using CIFS except that at the moment I do not have a licence for it. So before we invest bunch of $$$ I was checking if there is a cheaper solution to this problem.

Any suggestions are greatly appreciated.

[DSTAVERT]

Cheap isn't cheap if it adds  management overhead.

[lgardian]

I agree cheap is not the way to go, so let me rephrase that. We just spend 100k on new equipment so if I can save us 10k by implementing a solution that has been proven, I'm all for it.

[DSTAVERT]

Is there a reason you need to treat the 8TB as a single entity? Hard to believe that all 8TB of that data are equal and should be treated as equal. If it is equal and important then I would treat it as important and spend whatever is necessary to implement that level of importance.

[lgardian]

Yes, the data is very important. We will be storing medical images on this partition. It has to be available at all times for up to 7 years. The partition of that size is needed for the medical software that we are implementing. So with that said I can assume that going with the CIFS licence will be my best option?

[vmroyale]

Since I was not specific in my first post (my apologies) can I assume  that Microsoft iSCSI Initiator won't work in my setup because the  appliance is connected thru FC?

I'm fairly certain that you get iSCSI "for free" with the NetApp boxes.  You would have to add connectivity to it, preferably via dedicated NICs on your ESXi hosts.  This does add additional complexity (and possibly cost), but the 8 TB requirement sort of forces additional complexity somewhere in the design.  I will also add that the CIFS option is very nice on the NetApp.