I'm very new to all this so please go easy on me! I'm wondering whether you can run a NAS and virtualization with XenServer on the one box.

Basically, we need virtualization and we've picked XenServer over ESXi because XenServer seems to work on our commodity hardware. The box is a Core 2.66Ghz with 8Gb RAM. I need to virtualize Windows 2003, Windows 2008, Windows 2000 and CentOS.

I also need to accomodate for 2.5Tb worth of disks (500s and 750Gbs) which houses our data (mostly scratch/temporary files). Forgetting performance issues (the business is very small 3-5 people max) do you think XenServer is OK to do this?

Or do you think Xen+CentOS (+LVM XFS) may be better? I just want to make sure that the VMs are always available and that the NAS component is solid, they only have one machine to designate as a server.

4 Answers 4


You'll be fine with Xen on that machine then just add an OpenFiler (or similar) NAS VM to share your disk - it's pretty straightforward but I'm a little worried about your memory, you may need to consider adding more for all the VMs you're planning on.


We found it easier to install the XenServer to the local drive 1st w/o attaching the NAS/SAN, then once everything is up and running attach the NAS/SAN the OS should find it automatically. If it doesn't a quick reboot does the trick. If you are converting P2V make sure you grab the updated version of Xen's convert tool. Also, you will need to download the Linux add-on pack if you wish to run you CentOs box.

It is best to use Xen to format the NAS, as then you won't have to worry about any special file formats like GFS or the alike. We are about to roll XenServer out for our production servers also, we are switching from VMServer on top of RHEL. We are using a fibre san and the speed of the test servers compared to the current ones is wicked awesome.


I am working on something similar, and while I have been able to configure and run the nas (freenas, and openfiler) as a VM with the hw/raid managing the disk-array, and presenting it to the vm.

Biggest drawback, It loses some of the reason I prefer freenas (or any of the zfs native distro's) which is zfs. I have been working on finding something I can get the PV to work on so that I can add more raw disks and allow the zfs array to do its own magic, but that seems to the break point, because even with full PV, you are limited to 16 disks . I believe.. and ideally I would like to have the virtual head, manage everything at a disk level, not assigned to the xenhost. iirc And this is truelly unfortunate, vmware does this so may have to assign one of the servers in the farm as an esx. /me shudders at the thought. stupid non posix environments. Or could break the array's into 6 managable segments, but this limits growth and addition of another md/etc.. bah. back to research.

but as it pertains to your situation, using xenserver will limit you to attaching more then 16 disks to a vm, even with full pv drivers, and tools installed. iirc. It may have gone up with 6.2, I am working on testing that now. Just did an upgrade :D

cheers, slax

EDIT: I stand corrected it is currently 7 via xencenter or 16 via xe-commandline. still limits one to a single tray +system image... or a single tray +1 if you remap the cd to usb image for the appliance os. 16 disks mounted is btw an "unsupported configuration" so may not be an option for a production filer :D


That is the same setup I have on my host OS RHEL 5.3 xenserver with the same guest setup as you are looking to do, Win2k Win2k3 Win2008 and RHEL 5.3 on host server i had 600GB of SCSI that I partitioned in following way

                /root 12GB
                /boot 200MB
                <SWAP> 8GB
                and LVM created for 520GB all the Guest runinng on 
                .XM file at lvm and all config file at /etc/xen 

I used this tool because managing all guests it is very easy after installation of all the guest i have install Xenpv driver for all the windows server becauseof that you'll have good speed of network and as well disk I/O.

Now come main thing which your looking to cut slices of your NAS u can look for fdisk -l you will see your different paritions e.g. /dev/sda /dev/sdb /dev/sdc as early as i said why did use convert tool because all the noe you can add your NAS to require server as xvda looking to screen shotalt text

you attach the NAS volume to your win system and u r reboot you get a new hdd at win you can format in ntfs that how i did all the work.

  • 1
    i was fighting with same pro in my productions for cost cutting we cut 1st is physical server so there we are just going with same what i said above is all working with me with 500user exchange server and file server there many remote user thanks so much Thoreau bcoz i was feeling bit down Thanks ton
    – Rajat
    Commented Aug 28, 2009 at 13:12

You must log in to answer this question.