From: "Daniel P. Berrange" <berrange@redhat.com>
To: Keir Fraser <Keir.Fraser@cl.cam.ac.uk>
Cc: xen-devel@lists.xensource.com, "Carb, Brian A" <Brian.Carb@unisys.com>
Subject: Re: VM start time slows with large number of VMs
Date: Wed, 5 Sep 2007 18:37:32 +0100 [thread overview]
Message-ID: <20070905173732.GH5503@redhat.com> (raw)
In-Reply-To: <C304A1BA.D3AD%Keir.Fraser@cl.cam.ac.uk>
On Wed, Sep 05, 2007 at 06:11:06PM +0100, Keir Fraser wrote:
> xenstore slowness seems a reasonable hypothesis. How does performance of
> Œtime xenstore-ls >/dev/null¹ change as you increase the number of guests?
There's another issue with the way hotplug scripts do locking which exhbits
fairly pathelogical behaviour when a large number of guests are started
concurrently. We've got a patch we're evaluating which changes the use of
lock files + looping + sleeps, to instead use the 'flock' shell util.
I suspect the performance issues will be a combination of both the locking stuff
and the xenstore I/O. You might also want to try putting /var/lib/xenstored
onto tmpfs eg in initscripts before xenstored starts ...
mkdir /dev/shm/xenstored
mount --bind /dev/shm/xenstored /var/lib/xenstored
Dan.
--
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next prev parent reply other threads:[~2007-09-05 17:37 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-04 16:51 VM start time slows with large number of VMs Carb, Brian A
2007-09-05 17:11 ` Keir Fraser
2007-09-05 17:37 ` Daniel P. Berrange [this message]
2007-09-11 16:27 ` Carb, Brian A
[not found] ` <089B0D75973E1241B941D0A9854F23FC08F4CE10@USEA-EXCH2.na.uis .unisys.com>
2007-09-11 17:42 ` Mats Petersson
2007-09-24 14:18 ` Carb, Brian A
2007-09-06 16:24 ` Carb, Brian A
[not found] ` <089B0D75973E1241B941D0A9854F23FC08E92D5C@USEA-EXCH2.na.uis .unisys.com>
2007-09-06 17:29 ` Mats Petersson
2007-09-06 17:31 ` Keir Fraser
2007-09-06 17:44 ` Daniel P. Berrange
2007-09-06 19:25 ` Carb, Brian A
2007-09-06 21:25 ` Keir Fraser
[not found] ` <089B0D75973E1241B941D0A9854F23FC08E93337@USEA-EXCH2.na.uis .unisys.com>
2007-09-06 21:32 ` Mats Petersson
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