zHihaO
2006-Apr-20 02:11 UTC
[Xen-users] putting virtual domains into NFS mounts into turn mounted on DRBD devices.
Hi all, Has anyone ever put their domU into an NFS mount (which sits on top of a DRBD device) before? Will their be any performance issues if I were to do that? What I am trying to do now is I have got 2 machines that are xen enabled now. Currently I''m mounting them onto of LVM volumes. I intend to use NFS as mountpoints for my domU so that the 2 machines can use the same NFS mount to store the virtual machines. This is so that I can do a "xm migrate --live" across xen enabled machines in case anyone of them fails. I can''t do this on the fly with them currently mounted on LVM volumes. Thats the reason why I am looking at mounting them on an NFS. For the NFS mount, I intend to have 2 machines mirroring one another using DRBD as well as heartbeat to create a H.A solution to prevent the NFS from being a single point of failure. Welcoming any feedbacks regarding this..! thank you! -Zhihao _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thorolf Godawa
2006-Apr-20 10:28 UTC
Re: [Xen-users] putting virtual domains into NFS mounts into turn mounted on DRBD devices.
Hi,> Has anyone ever put their domU into an NFS mount (which sits on top > of a DRBD device) before? Will their be any performance issues if I > were to do that?NFS yes, but without DRBD. In a gigabit-net the performance was not a problem at all, I only had problems with some very new PRO/1000-nics. I replaced them with older PRO/1000-nics and everything ran fine from this point! -- Chau y hasta luego, Thorolf _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thorolf Godawa
2006-Apr-20 10:28 UTC
Re: [Xen-users] putting virtual domains into NFS mounts into turn mounted on DRBD devices.
Hi,> Has anyone ever put their domU into an NFS mount (which sits on top > of a DRBD device) before? Will their be any performance issues if I > were to do that?NFS yes, but without DRBD. In a gigabit-net the performance was not a problem at all, I only had problems with some very new PRO/1000-nics. I replaced them with older PRO/1000-nics and everything ran fine from this point! -- Chau y hasta luego, Thorolf _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
zHihaO
2006-Apr-20 10:48 UTC
Re: [Xen-users] putting virtual domains into NFS mounts into turn mounted on DRBD devices.
Hi all, I''m worried about this because we are going to be using these virtual servers for webhosting. Email and web traffic will be quite high and I''m afraid its gonna thrash the harddisk with the high disk i/o expected. And if the disk for storing the domUs are NFS exports..I''m not so sure if performance will be hit badly. comments anyone? or has anyone got a better suggestion?? -zhihao Thorolf Godawa wrote:> Hi, > >> Has anyone ever put their domU into an NFS mount (which sits on top >> of a DRBD device) before? Will their be any performance issues if I >> were to do that? > > NFS yes, but without DRBD. > > In a gigabit-net the performance was not a problem at all, I only had > problems with some very new PRO/1000-nics. I replaced them with older > PRO/1000-nics and everything ran fine from this point! >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Javier Guerra
2006-Apr-20 12:16 UTC
Re: [Xen-users] putting virtual domains into NFS mounts into turn mounted on DRBD devices.
On Thursday 20 April 2006 5:48 am, zHihaO wrote:> Hi all, > > I''m worried about this because we are going to be using these virtual > servers for webhosting. Email and web traffic will be quite high and I''m > afraid its gonna thrash the harddisk with the high disk i/o expected. > And if the disk for storing the domUs are NFS exports..I''m not so sure > if performance will be hit badly. comments anyone? or has anyone got a > better suggestion??if you''re using DRBD, you''ll get a shared block device. then you''re planning to add tree layers over that shared block device: 1) a filesystem. 2) NFS. 3) image files. instead of that, you could put LVM (or clvm) over that shared block device. it would be far less overhead and, if i understand correctly, you have two boxes, each one with a big local disk, currently using LVM. that doesn''t let you do live migration, but get''s the best performance, right? if you''re not planning to add a real SAN (iSCSI or otherwise), or more boxes in the near future, i think your best configuration would be something like that: use DRBD to replicate the PV between the two boxes, and then use LVM to create several LVs over that PV. the disk access would be mainly local, only the DRBD replication would happen transparently and asynchronously, without impacting disk access time. -- Javier _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Yura Pismerov
2006-Apr-20 13:29 UTC
Re: [Xen-users] putting virtual domains into NFS mounts into turn mounted on DRBD devices.
IMHO, there is not much I/O required for the domU to work and for
the applications to load from the binaries, so there is nothing wrong
with having the guest OS and application binaries on NFS (either using
NFS root or storing them in loopback containers).
As for the rest of your question, I hope you are not going to store
your application data (web content, email accounts, etc.) within the
loopback containers. If not, this question is not really related to Xen,
because
it is simply a choice between using or not using NFS for the user data
and web content. And it does not really matter whether or not you run
your applications on Xen at this point.
zHihaO wrote:
> Hi all,
>
> I''m worried about this because we are going to be using these
virtual
> servers for webhosting. Email and web traffic will be quite high and
> I''m afraid its gonna thrash the harddisk with the high disk i/o
> expected. And if the disk for storing the domUs are NFS
exports..I''m
> not so sure if performance will be hit badly. comments anyone? or has
> anyone got a better suggestion??
>
> -zhihao
>
> Thorolf Godawa wrote:
>
>> Hi,
>>
>>> Has anyone ever put their domU into an NFS mount (which sits on top
>>> of a DRBD device) before? Will their be any performance issues if I
>>> were to do that?
>>
>>
>> NFS yes, but without DRBD.
>>
>> In a gigabit-net the performance was not a problem at all, I only had
>> problems with some very new PRO/1000-nics. I replaced them with older
>> PRO/1000-nics and everything ran fine from this point!
>>
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
--
Yuri Pismerov, System Administrator
Armor Technologies (Canada) Inc.
P: 905 305 1946 (x.3519)
http://www.armorware.net
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