While this is not necessarily XEN dependant, here are a couple of our
observations:
1. Virtualization is memory dependant. On the systems we run, the
processors are idle most of the time, but the memory is almost always
full. As virtualization puts more systems on the physical hardware, the
constraints on the memory increase far more rapidly than the constraints
on other systems.
2. After memory, the bottleneck is I/O speed. In our systems I/O,
especially disk I/O, increases far faster than processor time. For this
reason, I would look to faster disk technologies, smarter RAID boards,
and higher disk caches.
This is not intended to downplay the need for more/better processors,
but simply to help prioritize the spending on the system being purchased
for virtualization.
+-------------------------------------------+
| Michael Surato |
| College of Arts and Letters |
| Michigan State University |
| 320 Linton Hall |
| East Lansing, MI 48824 |
| Voice: (517) 353-0778 Fax: (517) 355-0159 |
+-------------------------------------------+
-----Original Message-----
From: MSU Network Administrators Group [mailto:[log in to unmask]] On
Behalf Of Eric Weston
Sent: Monday, July 30, 2007 2:54 PM
To: [log in to unmask]
Subject: [MSUNAG] Red Hat Xen virtualization
Here's more questions for the virtualization gurus out there, in
particular those experienced with Red Hat Xen:
What is the optimal hardware for a server hosting multiple guest OSes?
are there certain processors that are preferable? Any to avoid? Is there
a rule of thumb regarding how much physical memory per guest OS? Any
other tips, warnings, advice, cautionary tales, caveats, monitions, etc?
Thanks much,
Eric W., Libraries Systems
