4:44 p.m.
On 10/07/2013 02:35 PM, Itamar Heim wrote:
On 10/07/2013 06:13 PM, Jason Keltz wrote:
> I've been experimenting with oVirt 3.2 on some old hardware, and am now
> preparing to buy new hardware for using oVirt 3.3 in production. I'm
> interested in any feedback about what I plan to purchase. I want to
> keep the setup as simple as possible. Our current environment consists
> of mostly CentOS 6.4 systems.
>
> The combined oVirt engine and file server will be a Dell R720 with dual
> Xeon E5-2660 and 64 GB of memory. The server would have an LSI 9207-8i
> HBA connected to the SAS backplane. The R720 enclosure has 16 x 2.5"
> disk slots. I would get 2 x 500 GB NLSAS drives for mirrored md rood
> (raid1), use 12 slots for RAID10 SAS 10K rpm drives (either 600 GB or
> 900 GB), and have an additional 2 spares. Data storage would be
> virtual machines, and some associated data. The O/S would be CentOS
> 6.4.
>
> The nodes would be 3 x Dell R620, dual Xeon E5-2690, 128 GB memory, each
> with just a single, small NL SAS root drive. There would be no other
> local storage. All VMs would use the file server as the datastore. The
> nodes would run oVirt node.
>
> In terms of networking, each machine would have 4 ports - 2 x 1 Gb
> (bonded) giving machines access to "public" network (that we do not
> control). The 2 x 10 Gb copper would be connected to a locally
> installed copper 10G switch that we fully control - 1 port used for
> storage, and 1 for management/consoles/VM migration.
>
> A few additional notes ...
>
> I chose to stick with software raid MD on the file server, mostly for
> cost, and simplicity. I have a lot of experience good with MD, and
> performance seems reasonable.
>
> I would have gone SSD for the file server root disk, but the cost from
> Dell for their SSD is prohibitive, and I want the whole system to be
> included in the warranty. NLSAS is the cheapest disk that will have
> support for the duration of the warranty period (with Dell servers, SATA
> drives are only warranted for 1 year).
>
> The nodes with 1 NLSAS drive... I've thought about replacing that with
> simply an SD card. It's not clear if this the best solution, or how
> much space I would need on that card. At least when I configure via the
> Dell web site, the biggest SD card it seems I can purchase with a server
> is 2 GB which doesn't seem like very much! I guess people guy bigger
> cards separately. I know a disk will work, and give me more than
> enough space and no hassle.
>
> I've chosen to keep the setup simple by using NFS on the file server,
> but I see a whole lot of people here experimenting with the new Gluster
> capabilities in oVirt 3.3. It's not clear if that's being used in
> production, or how reliable that would be. I really can't find
> information on performance tests, etc with Gluster and oVirt, in
> particular, with comparison of NFS and Gluster. Would there be a
gluster is still not available for centos 6.4, and there are some
issues with snapshots around it still for libgfapi.
for posixfs, its supported since 3.2.
Ok. I guess it's probably best that I stick with NFS for this time around.
> performance advantage to using Gluster here? How would it work?
by
> adding disk to the nodes, and getting rid of the file server (or at
> least turning the file server into a smaller engine only server)? How
> would this impact the nodes in terms of their ability to handle VMs?
> (performance?) I presently have no experience with Gluster whatsoever,
> though I'm certainly never against learning something new, especially
> should it benefit my project. Unfortunately, as I'm positive everyone
> can attest for is that it's just trouble finding the number of hours in
> the day :) There's one thing for sure - Gluster itself, while maybe not
> TOO complicated is still more complicated than an NFS only setup.
I don't have details on this, and hope others have.
but you are correct its an entirely different deployment architecture
between a central nfs server, and distributed storage on the nodes.
It would be helpful if the documentation for oVirt had more information
on this.
>
> As I've mentioned before, we don't use LDAP for authentication, so I'll
> be restricted to one admin user at the moment unless I setup a separate
> infrastructure for oVirt authentication. That will be fine for a little
> while. I understand that work may be underway for pluggable
> authentication with oVirt. I'm not sure if that ties into any of the
> items on Itamar's list though. Itamar? :) I was hoping to see that
> pluggable authentication model sooner rather than later so that I could
> write something to work with our custom auth system.
well, you could also launch an openldap/ipa/ad/etc. in a VM. of course
if it has issues you'd need admin@internal to fix it.
I was thinking of doing this if I had to, but it's still a lot of
headache for a few logins.
Is the pluggable authentication coming in a new version of oVirt?
>
> In terms of power management - my existing machines are using a Raritan
> KVM with Raritan power management dongles and power bars. I haven't had
> an opportunity to see if oVirt can manage the devices, but I guess if
> oVirt can't do it, I can continue to manage power through the KVM
> interface.
are they supported by fence-agents in centos?
I've never tried. I don't often need to power off hosts the hard way..
a reboot it usually fine. When I do need to power manage hosts, I go
into the Raritan KVM, click on the host, and turn it off, and back on,
and everything is fine. I haven't done any connection to Linux.
>
> Any feedback would be much appreciated.
>
With your experience with oVirt, any feedback on the hardware/NFS server
combination?
Jason.