Jump to content
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble

MSFN is made available via donations, subscriptions and advertising revenue. The use of ad-blocking software hurts the site. Please disable ad-blocking software or set an exception for MSFN. Alternatively, register and become a site sponsor/subscriber and ads will be disabled automatically. 

todarsey

Hyper-V VM's via NAS

Recommended Posts

I appologize if this is the wrong forum, but I figured either here on the Network section. I figured it could go either way.

I just purchased a QNAP TS-639 which has iSCSI. It is loaded with 6 2TB drives in a RAID 6.

Currently, I have 1 Win Server 08 running 6 VM's all on internal drives. I'm trying to plan for the future and I am wondering the best way to migrate the VM's over to the NAS. I am planning on sometime in the future to switch over to a Hyper-V cluster. With that being said, on the NAS, do I create an iSCSI target and mount that on the current server? Or, should I setup a file share on the NAS and run the VM from the share? It is my understanding that an iSCSI target should only be connected to one machine at a time. So, I am guessing that I shouldn't go the iSCSI target route if I am going to have a cluster.

Share this post


Link to post
Share on other sites

I am not sure about Hyper-V but in ESX multiple VM Hosts can attach to a single iSCSI target which enables the ability to use HA and DRS.

I believe iSCSI should be your aim as the packet size is optimised for large data transfer even before you include Jumbo Frames.

Share this post


Link to post
Share on other sites

If you're using 2008 R2 Hyper-V, you can use Cluster Shared Volumes (CSV) in your cluster. This can be done over iSCSI (in fact, I set these up all the time). Just be aware of the speed you will get on your NAS and iSCSI before moving over, to make sure performance is acceptable. Some NAS devices are faster than others, and some iSCSI implementations are faster than others (using a fast NIC on a fast network isn't always going to bring you 100% success, so having a dedicated iSCSI HBA is always recommended).

With all that said, you must be aware that the external storage device must support SCSI-3 persisitent reservations, and I don't believe the device you purchased does this. That would mean it would fail cluster tests, and as such would not be supported in a cluster configuration. You could probably still use the device as a mounted drive, but it would not be clusterable as shared storage (failover would... fail ;)). Note that FreeNAS does support this, so if you wanted to set up your own NAS solution for this, it could be done with free software.

Share this post


Link to post
Share on other sites

Thanks cluberti!

Can you recommend a good entry level NAS that will do this, or is there such a thing?

Share this post


Link to post
Share on other sites

There's no such thing - you again could use a spare PC with FreeNAS, but to get a clusterable pre-built device you're going to spend a few thousand dollars for an iSCSI enclosure.

Share this post


Link to post
Share on other sites

Ok, thanks once again.

I have been playing around with FreeNAS for the last couple of days and it seems to be missing the one freature I am looking for. That is the ability to upgrade/replace drives in the RAID configuration on the fly without having to create a new RAID set. Guess I'll have to keep looking or save up the funds to purchase what I need.

Share this post


Link to post
Share on other sites

If you have some more money, you might find a used raid controler (3ware, areca, adaptec) at a low price (i saw often 3ware ones for 50$ on ebay and of course they are only sata I). This way you won't get any problem replacing a faulty drive (with a fault tolerant array) or expanding the raid array.

Share this post


Link to post
Share on other sites

Well good new. Come to find out my qnap does support SCSI-3 persisitent reservations. I totally missed this when I was looking the first time. Scroll down to the iSCSI section.

QNAP TS-639 Pro Turbo NAS

Edited by todarsey

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...