From: Romain LE DISEZ <romain@ledisez.net>
To: kvm@vger.kernel.org
Subject: Host processes priority over guests
Date: Tue, 17 Jan 2012 07:45:44 +0100 [thread overview]
Message-ID: <4F151918.7040407@ledisez.net> (raw)
Hello all,
we are currently evaluating a migration from Xen to KVM.
We host our VMs on a SAN, access to LUNs is done by the iSCSI protocol,
all multipathed.
With Xen, we faced a problem when VMs were consuming a lot of CPU and a
lot of I/O. In this situation, the Dom0 did not get enough CPU time to
process the I/O requests through the iSCSI processes and to run the
iscsid daemon. So, the Dom0 was always loosing the iSCSI connection to
the SAN because of timeout (node.conn[0].timeo.noop_out_timeout).
We solved it by dedicating a core to the Dom0, as recommended in the Xen
FAQ.
Can this happen with KVM ? Why can(not) it happen ? If it could happen,
what is the recommended solution (renice, cgroups, ...) ?
Thanks for your help.
--
Romain LE DISEZ
reply other threads:[~2012-01-17 6:52 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4F151918.7040407@ledisez.net \
--to=romain@ledisez.net \
--cc=kvm@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.