From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?Jan_Kundr=E1t?= Subject: Re: poor I/O performance on domU Date: Mon, 17 Jan 2005 17:23:02 +0100 Message-ID: <41EBE666.60604@fzu.cz> References: <41E69C98.7090804@fzu.cz> <1105635651.25281.2.camel@localhost> <41E6AB02.6020801@fzu.cz> <1105637082.25283.12.camel@localhost> <41E92A7D.9070405@fzu.cz> <1105977610.29654.3.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1105977610.29654.3.camel@localhost> Sender: xen-devel-admin@lists.sourceforge.net Errors-To: xen-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Anthony Liguori Cc: xen-devel List-Id: xen-devel@lists.xenproject.org Anthony Liguori wrote: > On Sat, 2005-01-15 at 08:36, Jan Kundr=E1t wrote: >=20 >>Anthony Liguori wrote: >>yes, dom0 filesystems are on partitions located on hda. >=20 >=20 > My theory is that since hda is a single disk if you've got dom0 reading > and writing to it and another partition reading and writing to the same > disk at the same time both are going to be slower than if you were just > writing to hda on dom0. OK, I'll try to add another device and play with it. BTW, both dom0 and=20 the domain (running ttylinux) was idle, almost without disk activity.=20 I just run `hdparm` inside dom0, waited for results, dtto in domainU,=20 and repeated several times. > That's why I suggest trying it with a neutral device. >=20 >=20 >>I've tried exporting /dev/hda7 (not used neither mounted from dom0) as=20 >>sdb7 and I can get about 12.3 MB/s. From dom0 I get about 14.8 MB/s. >=20 >=20 > That seems pretty reasonable. Doesn't seem like there's a problem.=20 > Sharing partitions between dom0 and domU seems like a bad idea. Look > through the threads in the list about filesystem corruption. 30% performance loss seems like a problem for me ;-), comparing to <3%=20 (iirc) in xen's benchmarks. I just want to find out if the problem is in=20 Xen. Of course I'm *not* sharing the same partition between domains, I'm only=20 performing read benchmarks on the same disk location. -jkt --=20 cd /local/pub && more beer > /dev/mouth ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt