Xen and the art of Database performance

[Jose R R]

--- "McDougall, Marshall (FSH)"
<Marshall.McDougall at gov.mb.ca> wrote:

> >-----Original Message-----
> >From: redhat-list-bounces at redhat.com 
> >[mailto:redhat-list-bounces at redhat.com] On Behalf
> Of J. 
> >Refugio Rodriguez
> >Sent: Wednesday, October 24, 2007 2:59 PM
> >To: General Red Hat Linux discussion list
> >Subject: Re: Xen and the art of Database
> performance
> >
> >
> >--- "McDougall, Marshall (FSH)"
> ><Marshall.McDougall at gov.mb.ca> wrote:
> >
> >> A while back we took delivery of several Dell
> 2950
> >> servers to update our
> >> hardware environment which supports our Ingres,
> >> Sybase and DB2 systems.
> >> Ingres 2.6 and DB2 were running on RHEL 2.1,
> Sybase
> >> was running on
> >> RHEL3.  We were hoping to be able to maintain the
> >> same levels software,
> >> but the new hardware is not supported by RHEL2.1.
> 
> >> This is where the fun
> >> starts.  I built up several RHEL4 servers and
> >> installed the Database
> >> systems on them and gave them to the DBA's to
> test. 
> >> They promptly came
> >> back and said that they were up to 7 times slower
> >> than the previous
> >> hardware platforms, with the exception of DB2.  I
> >> ran some OS benchmarks
> >> and they came back up to 7 times faster than the
> >> previous hardware.  We
> >> worked on various tweaks and tunes to the OS and
> >> DBMS to no avail.
> >> At that point we started to engage the
> >> vendors/support orgs for the
> >> various products.  Sybase could do nothing to
> >> improve performance on the
> >> RHEL4 server, so we tried RHEL5(or advanced
> platform
> >> or whatever they
> >> are calling it this week). The performance was
> just
> >> as dismal.  We ended
> >> up going back to RHEL3U9 to get the Sybase
> >> environment to an acceptable
> >> performance level. 
> >> Ingres is another story.  First they said try
> Ingres
> >> 2006.  It worked,
> >> but it has significant implications to our
> OpenRoad
> >> development
> >> environment, and as such is not really an option.
>  I
> >> went the same route
> >> as before with the various flavours of RHEL and
> it
> >> made no difference.
> >> Finally, I built a RHEL5 server, installed VMWare
> >> Server, and created a
> >> RHEL2.1 guest on that.  We now have performance
> >> where we want it.  The
> >> downside is that on my server with 8GB of ram I
> can
> >> only use 3.6GB for
> >> the VM. 
> >> My options as I see them now are; Install VMWare
> ESX
> >> and see if that
> >> buys me anything, or spend the time and effort to
> >> see if Xen will be of
> >> benefit.  The problem with the latter is that
> >> according to the doc RHEL
> >> 2.1 is not a supported OS on RH5.
> >
> >Indeed, XenSource does not include the appropriate
> >modified kernel for RHEL 2.1 and, accordingly, is
> not
> >officially supported on XenEnterprise 3.2 or
> higher.
> >
> >Notwithstanding, you can create an proper Linux
> kernel
> >for your RHEL 2.1 by installing the same into a
> >machine that has the CPU virtualization extensions
> >(i.e., hardware assisted virtualization).
> >
> >Once you successfully install/modify your RHEL 2.1
> >under XenEnterprise in the above hardware assisted
> >virtualization environment, you can use the image
> on
> >older non-hardware assisted virtualization CPUs.
> >
> >Before going to ESX, you may want to evaluate
> >XenEnterprise in price and performance.  Back in
> >version 3.2 of XenSource XenEnterprise, you could
> >allocate to an virtual machine up to 15GB of
> memory.
> >
> >Disclaimer: Metztli Information Technology is an
> >Xensource Certified Partner.  
> >> 
> >> So, after all this,  the gist of my post is; Has
> >> anybody successfully
> >> sparked up a RHEL 2.1 guest, using more than 4 GB
> of
> >> RAM, on a RH5
> >> virtual platform, or, has anyone installed Ingres
> >> 2.6 on a Linux 2.6
> >> kernel and made it perform at an expected level? 
> >> Thanks for reading
> >> this far.
> >> 
> >> Regards, Marshall
> >> --
> >> redhat-list mailing list
> >> unsubscribe
> >>
>
>mailto:redhat-list-request at redhat.com?subject=unsubscribe
> >>
> https://www.redhat.com/mailman/listinfo/redhat-list
> >> 
> >Jose R Rodriguez
> >http://www.metztli-it.com
> >
> >
> Thanks for the input Jose.  It sounds like it's
> doable with Xen, but it
> also sounds like it's painful.  Yesterday I
> downloaded a time bomb trial
> of ESX and had it and a RHEL2.1 VM running in about
> 1.5 hours.  I've
> taken a lot longer than that just trying to
> understand the Xen docs that
> I can find.
> 
> Regards, Marshall
>
Marshall,
 
It takes approximately 10 minutes to install the Linux
based XenServer into your physical server on the bare
metal.  You then need to install the administration
console into another machine from where you will be
able to install, configure, and/or migrate live VMs as
your storage needs change.

Whereas XenSource XenServer 3.2 products were for
32-bit architecture, XenServer 4.0 has been updated to
64-bit.

The installation of your RHEL 2.1 is done as you did
under ESX, and the hardware requirements are similar,
i.e., both need hardware virtualization support.  The
latter is found in hardware with Intel processors
shipped since the end of 2005 and hardware with AMD
equivalents that shipped since August 2006.

For a trial download of XenEnterprise (and/or a no
cost XenExpress download with VM guest support memory
allocation of up to 4GB): <
http://www.citrixxenserver.com/Pages/Download.aspx >

Documentation: <
http://docs.xensource.com/XenServer/4.0.1/ >

Knowledge base: < http://kb.xensource.com/kbindex.jspa
 >

Support forums: <
http://forums.xensource.com/index.jspa >

You may also be interested in a feature similar to
Fedora 7, CentOS 5, and RHEL 5 VM manager:

"Red Hat Enterprise Linux 5 and SUSE Enterprise Linux
10 may be installed directly from vendor network
repositories using the vendor-provided Xen kernels,
and thus no longer require hardware-assisted
virtualization during the installation process."

(Please see the release notes <
http://docs.xensource.com/XenServer/4.0.1/releasenotes/releasenotes.html
 >)

Best regards.

Jose R Rodriguez
http://www.metztli-it.com