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Re: [Xen-users] backing up DomU with Netbackup is 3 times slower

To: Andrew Lyon <andrew.lyon@xxxxxxxxx>
Subject: Re: [Xen-users] backing up DomU with Netbackup is 3 times slower
From: abhi datt <abhi.datt@xxxxxxxxx>
Date: Sun, 23 Aug 2009 21:34:09 +0530
Cc: xen-users@xxxxxxxxxxxxxxxxxxx
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Thanks Andy. I''ll try that too. Do you suggest some thing else too, to be tuned besides using PV because when I ran this performance test
inside guest (windows 2003) with and without PV drivers I didn't find much difference in read and write speed.


On Sun, Aug 23, 2009 at 6:34 PM, Andrew Lyon <andrew.lyon@xxxxxxxxx> wrote:
On Sun, Aug 23, 2009 at 10:23 AM, abhi datt<abhi.datt@xxxxxxxxx> wrote:
> Hi all,
> We have recently migrated our critical servers like MS Exchange, MS SQL etc.
> to Xen 3.0.3 on RHEL 5.3 server. Although servers are in production and
> performance is acceptable, but when we attempt to take backups of DomUs
> (same way as we used to take in physical servers scenario) using Netbackup v
> 6.5 application from Symantec, it takes 3x more time to finish the backup.
> What used to take earlier 18 minutes (exchange mailbox level backup) is now
> taking 90 minutes.
> Our host servers are brand new Dell 2950 with 32 GB RAM and 8 Cores, out of
> which we have committed 2 cores (read 2 vCPUs)  and 4 B RAM to exchange,
> which is equivalent of its earlier physical server configuration.
> Is there anyway that this can be taken care of as backup is an integral part
> for any organization
> thanks
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-users

Are you using pv drivers? Perhaps redhat provide pv drivers of their own?

You can get James Harper's gpl pv drivers from
http://www.meadowcourt.org/downloads but they work a lot better with
Xen 3.4 than 3.0.3, the drivers will give a huge increase in i/o
performance on the hd and network, but I would upgrade Xen if you want
to try them.


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