Hi William,
Thanks for your reply.
Basically I would like to utilise x86_64 especially since
the hardware supports it.
I will be working with hardware that will have 8GB ram.
The idea is a VPS will be allocated x amount of ram that should be a hard limit
similar to how a normal dedicated server would behave when you hit your
physical ram limit.
Disk IO will be fairly moderate, and won’t be beyond
fairly standard levels.
-Alan
-----Original Message-----
From: William Pitcock [mailto:nenolod@xxxxxxxxxxxxxxxxxx]
Sent: Thursday, 7 August 2008 12:15 PM
To: Alan Lam
Cc: venefax; xen-users
Subject: RE: [Xen-users] Xen Setup
Hi,
On Wed, 2008-08-06 at 18:03 -0700, Alan wrote:
> We don’t do anything fancy really, just the straight
out VPS like no
> other. We don’t map PCI devices to VPSes etc. It
really is just an OS
> on a disk with a memory allocation.
>
>
>
> Considering you have both, would you be able to give
a brief
> advantages/disadvantages between using OpenVZ and
Xen? I have been
> considering OpenVZ as well as Xen and Xen was
looking a little better
> on the IO performance side.
>
Xen has no real advantages over Virtuozzo with I/O,
although it is very easy to integrate SAN solutions like ATA-over-Ethernet and
iSCSI. I have a fairly large cluster mostly fed by an ATA-over-Ethernet meshed
SAN, and the performance is quite acceptable.
>
>
> Thing is, we would like to be able to take advantage
of the fact the
> CPU can handle 64bit and would like to run a 64bit
Xen host along with
> 64bit VPSes. I am not sure if Xen can do this or
not, nor whether
> OpenVZ can either.
>
Roughly 98% of my customers are on x86-64 instances.
Approximately 20 are still on x86-32 instances. All of our dom0's except for
one node is
x86-64 capable (dual Opteron 2216 hardware from Rackable
Systems).
Personally, I have found that Xen's behaviour is a lot
more reliable on
x86-64 than it is on x86-32. But maybe that's just my
setup.
>
>
> If you look at my original post to the mailing list,
we are
> considering the switchover because of new
hardware/newer OS.
>
What hardware do you have? Virtuozzo's memory
overcommitting would probably be useful to you if you are working with lowspec
hardware (<= 8GB). I know that with Xen, we have reached capacity limits a
few times because the customer growth was increasing more rapidly than we could
order and rack more hardware for the clusters.
Furthermore, anything I have said about Virtuozzo can be
applied to OpenVZ without much difficulty.
William
