[CentOS] "near native" performance with xen?

[Ross S. W. Walker]

> -----Original Message-----
> From: centos-bounces at centos.org 
> [mailto:centos-bounces at centos.org] On Behalf Of Johnn Tan
> Sent: Monday, August 06, 2007 3:52 PM
> To: CentOS mailing list
> Subject: Re: [CentOS] "near native" performance with xen?
> 
> Ross S. W. Walker wrote:
> > Of course you need physical volumes but look for a storage
> > solution that will also run as direct to disk as possible,
> > maybe something based on the newer SATA/SAS where the RAID
> > logic is built into the enclosure and a plain SATA/SAS
> > card is in the server which can be actively shared between
> > multiple domUs.
> > 
> > If that is out of your budget then use some type of hardware
> > RAID for your volumes to get rid of any use of software RAID
> > in dom0 for guest storage.
> 
> I'm not sure what the distinction is between your first 
> paragraph and the second. When I read the first paragraph, I 
> thought: "hardware RAID" but it seems like you're referring 
> to something else.

The distinction is small, but the costs are great.

1st one, the RAID technology is in the enclosure where you can
have multiple initiators (even from the same host) directly
access the logical disks in the arrays, you can also have
multiple paths to those logical disks. PV'ing these drivers
would be a lot simpler then if the RAID technology were in the
controller card itself. This isn't iSCSI, but the newer SAS/SATA
technology. The controller card is simpler and can be abstracted
much in the same way a network adapter can be.

The 2nd is what you are familiar with RAID controller hooked
into JBOD enclosure.

> > Same goes for the network side of things. Install the latest
> > PV drivers in the domUs to get the latest advances.
> 
> I didn't realize these existed. I just used whatever was 
> pulled down when I install xen/kernel-xen via yum. Where can 
> I get these PV drivers?

My mistake I was thinking HVM guests.

If you want the latest for HVM I think Novell sells them, or
you can try the 5.1 versions in testing.

-Ross


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