> -----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. -Ross ______________________________________________________________________ This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and permanently delete the original and any copy or printout thereof.