From: Ron Edison <ron@idthq.com>
To: kvm@vger.kernel.org
Subject: writeback cache + h700 controller w/1gb nvcache, corruption on power loss
Date: Sat, 14 Apr 2012 21:16:16 -0700 (PDT) [thread overview]
Message-ID: <17899694.655.1334463376853.JavaMail.root@sys1.internetdefensetechnologies.com> (raw)
In-Reply-To: <22130654.645.1334462335379.JavaMail.root@sys1.internetdefensetechnologies.com>
dear list,
I recently had a machine lose power that was unfortunately running between 15-20 kvm guests.
The server is a Dell R710 with an H700 controller with 1gb of nvcache. Writeback cache is enabled on the controller. There is a mix of linux and windows guests, some with qcow2 format vdisks and others with raw format vdisks. Some of these guests have wb cache enabled on the vdisks and some do not.
About a third of the guests experienced disk corruption after coming back up after the host lost power. Based on what I have read, this should not have happened using the above configuration. The operating system is Centos 6.2, this is all direct attached storage configured as raid 1 mirrors.
I'm hoping someone has a comment or suggestion on this so that I can take action to prevent corruption in the future.
The motivation to enable write caching is primarily performance.
Thanks,
Ron
next parent reply other threads:[~2012-04-15 4:16 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <22130654.645.1334462335379.JavaMail.root@sys1.internetdefensetechnologies.com>
2012-04-15 4:16 ` Ron Edison [this message]
2012-04-16 8:34 ` writeback cache + h700 controller w/1gb nvcache, corruption on power loss Stefan Hajnoczi
2012-04-16 8:51 ` Ron Edison
2012-04-17 8:41 ` Stefan Hajnoczi
2012-04-24 13:43 ` Avi Kivity
2012-04-25 3:57 ` Christoph Hellwig
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