[CentOS-devel] Back-port md raid1/10 BIO_RW_SYNC patch for DRBD

Thu Mar 1 05:17:04 UTC 2007
Ross S. W. Walker <rwalker at medallion.com>

> -----Original Message-----
> From: centos-devel-bounces at centos.org 
> [mailto:centos-devel-bounces at centos.org] On Behalf Of Ross S. 
> W. Walker
> Sent: Thursday, March 01, 2007 12:03 AM
> To: The CentOS developers mailing list.
> Subject: RE: [CentOS-devel] Back-port md raid1/10 BIO_RW_SYNC 
> patch for DRBD
> 
> > -----Original Message-----
> > From: centos-devel-bounces at centos.org 
> > [mailto:centos-devel-bounces at centos.org] On Behalf Of Ross S. 
> > W. Walker
> > Sent: Wednesday, February 28, 2007 11:32 AM
> > To: The CentOS developers mailing list.
> > Subject: RE: [CentOS-devel] Back-port md raid1/10 BIO_RW_SYNC 
> > patch for DRBD
> > 
> > > -----Original Message-----
> > > From: centos-devel-bounces at centos.org
> > > [mailto:centos-devel-bounces at 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 at centos.org
> > > > > > [mailto:centos-devel-bounces at centos.org] On Behalf 
> Of Ross S.
> > > > > > W. Walker
> > > > > > Sent: Sunday, February 25, 2007 12:24 PM
> > > > > > To: centos-devel at 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.
> > 
> 
> Ok, I just updated to that kernel, 
> kernel-2.6.9-42.0.10.plus.c4, and I do not see the patch in there?
> 
> Did it miss the final cut?

My bad I spoke too soon, it is in there as linux-2.6.9-raid-bio-rw-sync.patch.

Sorry,

Ross

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