| |
|
 |
|
 |
|
|
|
| |
|
|
xen-users
Re: [Xen-users] XEN and clustering?
Steven Wilcoxon wrote:
I would think running LVM in Dom0 instead of DomU gains you performance
by using Dom0's CPU & disk cache instead of taking it out of the DomU
resources.
First off, the overhead of LVM in i/o and such is likely a small
percentage of the i/o of Xen itself, which we all know to be very small.
In other words, its overhead is negligible no matter where it's run.
Second, I don't know what you're referring to here with cpu and disk
cache, especially with regard to disk cache, as LVM does little or none
as far as I know. I run my dom0's with a hard-coded 512MB so I don't
have any cache there anyway, but I'm running LVM on top of LVM (phy:
mappings of lv's) so cache is irrelevant). Unless you're using tap:aio,
if you're going to use cache, it's in the domU.
Third, if there is some resource utilization going on specific to a
domU, I'd rather have that happen in the domU where it has minimal
impact on other domU's rather than in dom0 where it affects them all.
There are exceptions: you don't want things that have to cross the
hypervisor twice to exist in domU like RAID and multipathing.
John
--
John Madden
Sr UNIX Systems Engineer
Ivy Tech Community College of Indiana
jmadden@xxxxxxxxxxx
_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users
|
|
|
| |
|
Home