Question about ESXi and NFS

[CosmoJoe]

Greetings! I am hoping to get feedback about the following possible scenerio.

Computer 1:

Computer running Windows Server 2008. Large amount of available storage, either via dedicated hardware raid or 'software'/ICH10 raid.

Computer 2:

Computer running ESXi v4 (installed on local hard drive). Core2Quad w/ 8GB RAM. Load of approximately 4-5 VMs. Each VM will be light IO load (lab environment domain controllers, MySQL server, web server).

I have three questions:

1. Is there any issue with using the space on Computer 1 via Windows 2008 NFS to host the VMs which will run on Computer 2.

2. Since I am not using hardware RAID on Computer 2, I will not have RAID1 for redundancy. If the local hard drive fails, but the VMs are on a redundant protected NFS share on Computer 1, is there any data loss aside from the need to reinstall ESXi on a new hard drive?

3. Can anyone advise of the performance of a "software" RAID (most likely RAID5) NFS share (ICH10, etc) from the standpoint of hosting VMs?

Thanks in advance!

[DSTAVERT · Accepted solution]

1. Is there any issue with using the space on Computer 1 via Windows 2008 NFS to host the VMs which will run on Computer 2.

While the Windows NFS service is not the most ideal it will work just fine. You will want to make sure that there is no automated update etc. and confine the machine to storage duties only.

2. Since I am not using hardware RAID on Computer 2, I will not have RAID1 for redundancy. If the local hard drive fails, but the VMs are on a redundant protected NFS share on Computer 1, is there any data loss aside from the need to reinstall ESXi on a new hard drive?

It wouldn't be any different than a hard crash on any machine. You do have the risk of corrupted data whether it is physical or virtual.

3. Can anyone advise of the performance of a "software" RAID (most likely RAID5) NFS share (ICH10, etc) from the standpoint of hosting VMs?

Without a hardware raid controller with caching enabled you will not get the best disk performance. Caching controllers have on board RAM and will require a battery to protect the cache in the event of a power outage.

[CosmoJoe]

Thank you very much for the info. I am trying to avoid the need for a hardware RAID controller, as it seems even the most affordable supported by ESXi are $300 and up, but I certainly want protection for the VMWare installation itself.

[dburgess]

1. No that should work fine. Note that we only support TCP based NFS not UDP but as far as I remember the NFS server on W2K8 will support that.

2. No all your VM data will be fine, you may loose some configuration information which you can recover pretty easily. You could use host profiles in VC if you have access to that technology or a backup or better a post install script that configures your ESX server to your requirements. In the next release of vSphere you will be able to PxE the ESXi install image (this is technically a future but it has been widely trailed on blogs so is effectively public info nowadays) and invoke a post install script which should for the most part make the install almost stateless.

3. So far my experience of software NFS has been variable - I have not tried the W2K8 one so I would do some testing around that. If you have a light i/o load you should be fine though.

[DSTAVERT]

The hardware raid controller isn't for ESXi it is for your Windows server. You can choose what you like if it is supported by Windows.

Once loaded ESXi runs from RAM so disk failure is less critical than you might think. There is very little writing to disk. I use USB sticks for my ESXi installs. It is in fact possible to pull the USB stick once ESXi loads (TOTALLY a BAD IDEA).

[CosmoJoe]

dburgess ~

Thanks so much! That is precisely what I was looking for.

[CosmoJoe]

DSTAVERT~

Correct, I will probably go with a hardware RAID controller for the Windows box, but I absolutely want to avoid having to spend the money for a second RAID card for the ESXi box. (so much $$$ !!)

My main concern was trying to plan for the unforeseen. For example, my home computers are joined to a domain and the two DCs are both VMs. If the hard drive melted down in the ESXi box, I wanted to know how much risk that would pose to the integrity of the remotely hosted VMs, although I will probably be backing them up as well somehow.

It sounds like for all practical intents and purposes, it is a risk I can live with

[DSTAVERT]

As I said I don't even use physical disks for ESXi. Since I have no disks I don't require a disk controller either.

[DSTAVERT]

Have a look at http://communities.vmware.com/docs/DOC-8760 for a great solution to backup.