[ovirt-users] fileserver as a guest oVirt

Thu Jul 17 12:53:14 UTC 2014

Thanks for your thorough answer and explaination. I have gone with the direct lun to start with. I bought new Sata disks and added them to the storage chassi for the purpose of file sharing. 

Regards,
Niklas 

> On 17 jul 2014, at 14:33, "Daniel Helgenberger" <daniel.helgenberger at m-box.de> wrote:
> 
> Hello,
> 
> for some reason the message was flagged spam; so there was a deplay.
> 
> oVirt supports direct LUNs. These LUNs are often already partitions of
> some RAID enclosure.
> AFAIK the MSA60 is a JBOD. You can use the p411 controller to create
> your partitions / LUNs.
> 
> The Virtio-SCSI paravirt driver supports a wide range of (=most) SCSI
> commands. This way clients can access them as 'real' SCSI devices.
> 
> If you did partition the LUN with parted, then the client(s) will see
> these partitions also, along with the file system on it. 
> 
> As you might know, you cannot have 'normal' file systems mounted rw on
> several machines at one, you need a cluster file system; see examples in
> [1]; there are several open source FS's around.
> 
> Also, nothing stops you from mounting a file system read only on several
> hosts.
> 
> One note on the subject, though:
> I consider shared disk file systems as 'old' approach. I support them in
> our setup because of historical reasons. 
> Today in a new deployment I would tend to use more 'modern' scale out
> file systems like GlusterFS (support in oVirt is quite well) or
> Ceph/Rados as object store file system. Using the native clients, you
> basically have a shared disk file system with less bottlenecks (MDC's in
> shared disk fs). Also, both examples have APIs - an application using
> this can greatly benefit in performance. Again, I consider using APIs
> for file storage the approach of the future.
> 
> If you need to attach NFS / CIFS clients, you can always reshare these
> file systems and use (p)NFS or CTDB if you want to cluster this.
> 
> Note, with one host and one JBOD this makes little sense to me.
> 
> [1] http://en.wikipedia.org/wiki/Clustered_file_system
> [2] https://ctdb.samba.org/
> 
>> On Mo, 2014-07-14 at 08:10 +0000, Niklas Fondberg wrote:
>> Thanks, after reading it makes sense. I suppose I need to drop my hope of
>> having sharing possibility with the host.
>> I have two questions that you might be able to answer:
>> 1. Does direct LUN support partitions or only whole devices
>> 2. Do you know of any open source way of making them shareable to Ovirt?
>> 
>> My setup is simple:
>> - HP DL380 with dual Xeon and lots of RAM. Boots from seperate disk (USB)
>> - MSA60 with p411 attached to the HP DL380
>> 
>> When we grow oVirt we will grow with DL360¹s and use all shared storage
>> from the guest fileserver on the first host.
>> 
>> 
>> 
>> On 14/07/14 08:57, "Daniel Helgenberger" <daniel.helgenberger at m-box.de>
>> wrote:
>> 
>>> Hello,
>>> 
>>> just add my 2ct: I did a lot of bench marking for our SAN (FC LUN's). I
>>> also need file servers for our SMB Clients.
>>> 
>>> I recommend using Direct Attached LUNs for your purpose and attach them
>>> to the VMs as VirtIO-SCSI disks. You can even added them as shareable to
>>> oVirt if you deploy some kind of SAN file system (we use Quantum's
>>> StorNext).
>>> 
>>> Bottom line, the implementation of VirtIO-SCSI is so well done and
>>> support in oVirt is great. I cound not see any bottlenecks in the
>>> visualization. For the foreseeable future I will not deploy bare metal
>>> file Servers again.
>>> 
>>> HTH,
>>> 
>>>> On So, 2014-07-13 at 15:47 +0000, Niklas Fondberg wrote:
>>>> 
>>>> From: Karli Sjöberg <Karli.Sjoberg at slu.se<mailto:Karli.Sjoberg at slu.se>>
>>>> Date: Sunday 13 July 2014 14:51
>>>> To: Niklas Fondberg <niklas at vireone.com<mailto:niklas at vireone.com>>
>>>> Cc: "users at ovirt.org<mailto:users at ovirt.org>"
>>>> <users at ovirt.org<mailto:users at ovirt.org>>, Karli Sjöberg
>>>> <Karli.Sjoberg at slu.se<mailto:Karli.Sjoberg at slu.se>>
>>>> Subject: Re: [ovirt-users] fileserver as a guest oVirt
>>>> 
>>>> 
>>>> Den 12 jul 2014 22:49 skrev Niklas Fondberg
>>>> <niklas at vireone.com<mailto:niklas at vireone.com>>:
>>>>> 
>>>>> 
>>>>> 
>>>>>> On 12 jul 2014, at 16:57, "Karli Sjöberg"
>>>>> <Karli.Sjoberg at slu.se<mailto:Karli.Sjoberg at slu.se>> wrote:
>>>>> 
>>>>>> 
>>>>>> Den 12 jul 2014 15:45 skrev Niklas Fondberg
>>>> <niklas at vireone.com<mailto:niklas at vireone.com>>:
>>>>>>> 
>>>>>>> Hi,
>>>>>>> 
>>>>>>> I'm new to oVirt but I must say I am impressed!
>>>>>>> I am running it on a HP DL380 with an external SAS chassi.
>>>>>>> Linux dist is Centos 6.5 and oVirt is 3.4 running all-in-one (for
>>>> now until we need to have a second host).
>>>>>>> 
>>>>>>> Our company (www.vireone.com) deals with system architecture for
>>>> many telco and media operators and is now setting up a small own
>>>> datacenter for our internal tests as well as our IT infrastructure.
>>>>>>> We are in the process of installing Zentyal for the SMB purposes
>>>> on a guest and it would be great to have that guest also serving a fs
>>>> path directory with NFS + SMB (which is semi crippled on the host after
>>>> oVirt installation with version 3 et.c.).
>>>>>>> 
>>>>>>> Does anyone have an idea of how I can through oVirt (seen several
>>>> solutions using virsh and kvm) letting my Zentyal Ubuntu guest have
>>>> access to a host mount point or if necessary (second best) a seperate
>>>> partition?
>>>>>>> 
>>>>>>> Best regards
>>>>>>> Niklas
>>>>>> 
>>>>>> Why not just give the guest a thin provision virtual hard drive and
>>>> expand it on a demand basis?
>>>>>> 
>>>>>> /K
>>>>> 
>>>>> Thanks for the advise but this would not suite us I'm afraid. It
>>>> would be difficult wrt incremental backups as well as host machine
>>>> file-routines.
>>>> 
>>>> Well, going by Occam's raizor; the simplest answer is usually correct.
>>>> Can't really tell what you mean by file-routines but backups would be
>>>> well served by snapshots (can't get more incremental than that) and
>>>> disaster recovery could be as easy as a rsync from inside the guest to a
>>>> remote machine.
>>>> 
>>>> The biggest pros here is the ease of being able to setup an export
>>>> domain, attach, export the VM, detach domain, and then attach and import
>>>> to a "real" setup when the AIO starts feeling crowded later on. Thinking
>>>> ahead is never a bad thing, no?
>>>> 
>>>> /K
>>>> 
>>>> Thanks for your suggestions!
>>>> The thing also is that the performance will be very bad if we have the
>>>> 25TB SAS array shared for our purposes (lots of media streaming) using a
>>>> virtual disk.
>>>> What I am after (after more reading) is support for virtio-9p-pci
>>>> (http://www.linux-kvm.org/page/9p_virtio) using oVirt. Alternative is
>>>> the Direct LUN hook (http://www.ovirt.org/VDSM-Hooks/directlun, if I can
>>>> figure out how to work with hooks...)
>>>> Any chance anybody has an answer for these questions?
>>>> 
>>>> _______________________________________________
>>>> Users mailing list
>>>> Users at ovirt.org
>>>> http://lists.ovirt.org/mailman/listinfo/users
>>> 
>>> -- 
>>> 
>>> Daniel Helgenberger
>>> m box bewegtbild GmbH
>>> 
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> 
> -- 
> 
> Daniel Helgenberger 
> m box bewegtbild GmbH 
> 
> P: +49/30/2408781-22
> F: +49/30/2408781-10
> 
> ACKERSTR. 19 
> D-10115 BERLIN 
> 
> 
> www.m-box.de  www.monkeymen.tv 
> 
> Geschäftsführer: Martin Retschitzegger / Michaela Göllner
> Handeslregister: Amtsgericht Charlottenburg / HRB 112767 