a virtual NAS

[tmclaugh-VThn6mlTRQFChFL4AGkBsw at public.gmane.org (Tom McLaughlin)]

Tom Metro wrote, On 05/17/2009 06:03 PM:
> Tom McLaughlin wrote:
>> I'm the process of rebuilding my home network and moving things from 
>> physical machines to virtual machines right now and a NAS VM is on my 
>> list.
> 
> What do you see as an advantage to implementing a NAS as a VM?
> 

It just happens that most of my systems here at home which need my 
current "NAS box" (really just an openbsd box with a big disk holding a 
bunch of NFS and SMB shares, FTP mirrors, and CVS mirrors) happen to 
live on my current VM box.

> If the disks themselves are held in an external subsystem (like one of 
> the 4-bay SATA subsystems with multi-lane eSATA cabling that are 
> becoming economical), and you have two VM hosts, such that if one fails, 
> you can connect the subsystem to the other machine and restart the NAS 
> service there, then it makes sense. (Even better if you could make the 
> switch over automatic, but then you'd have to go with a more expensive 
> interface, like iSCSI or AoE.)

The NAS is for the VMs, not the VM host.  I haven't bothered worrying 
about VM host failure for the simple reason that the only physical 
things I have left don't rely on anything living on the VM host.  My 
limited funds just happen to be better spent elsewhere at the moment. 
:-/  Building a box or two for backups (including VM backups) I think 
are a better way to spend what I have.

> 
> 
>> I may end up playing with FreeNAS though OpenFiler looks to be nice too.
> 
> Assuming your VM host is running Linux, then a VM also makes sense as a 
> way to run FreeNAS. The case seems less compelling for OpenFiler. Unless 
> you really like the OpenFiler GUI, just install Samba on the host.
> 

The VM host is running VMware ESXi.  I don't see any less compelling 
case for running OpenFiler in a VM than FreeNAS though in my case. 
However after looking at both of them I'll probably just end up 
installing some OS and setting up everything I need myself.

> I wonder what kind of performance hit you'd take by running FreeNAS in a 
> VM, given that you'd probably be running it on a much faster CPU than 
> what's typically found in low-power NAS appliances.

The only thing I've noticed is NFS performance in general seems to just 
suck.  Just been using simple `dd` and see no difference in write speed 
from VM to VM, physical to VM, VM to physical, and physical to physical. 
  This has become an issue with two of my VMs which unfortunately have a 
lot of disk activity on an NFS mount.
<snip>

tom

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