-----Original Message----- From: centos-devel-bounces@centos.org [mailto:centos-devel-bounces@centos.org] On Behalf Of Johnny Hughes Sent: Wednesday, February 28, 2007 10:08 AM To: CentOS-Devel Subject: RE: [CentOS-devel] Back-port md raid1/10 BIO_RW_SYNC patch for DRBD
On Wed, 2007-02-28 at 02:08 -0600, Johnny Hughes wrote:
On Tue, 2007-02-27 at 21:10 -0500, Ross S. W. Walker wrote:
-----Original Message----- From: centos-devel-bounces@centos.org [mailto:centos-devel-bounces@centos.org] On Behalf Of Ross S. W. Walker Sent: Sunday, February 25, 2007 12:24 PM To: centos-devel@centos.org Subject: [CentOS-devel] Back-port md raid1/10 BIO_RW_SYNC patch for DRBD
Attention CentOS Developers,
Here is a back-port of Lars Ellenberg's md raid1/10
patch from 2.6.19+
to 2.6.9. It seems the md raid1 and raid10 drivers were
stripping the
BIO_RW_SYNC flags on requests which caused a severe performance penalty for DRBD when writing it's meta-data to these volumes.
The patch is attached as well as inlined:
No comments?
I just put it in the new CentOSPlus kernel (that I am currently testing).
Should be out later today (if it works).
OK ... the released CentOS-Plus kernel (2.6.9-42.0.10.plus.c4) has that patch installed on x86_64 and i386 ... and I did install it and test with DRBD. The systems it is on are running OK.
Excellect, I am currently running the patch on my x86_64 plus kernel here with no problems, and I have the OS booting off of RAID1, I have the meta-data as a LVM on the OS vg and no problems and a significant improvement with my large DRBD volumes.
Lars did review the fixes too and gave them the ok, so it wasn't completely without review.
-Ross
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