From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jun'ichi Nomura Date: Tue, 12 Dec 2006 17:55:47 -0500 Subject: [PATCH LVM2] Use parallel areas constraint for mirror log addition Message-ID: <457F3373.4090600@ce.jp.nec.com> List-Id: To: lvm-devel@redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi, This patch fixes the problem that lvconvert-ing corelog mirror to disklog mirror allocates the mirror log on the same device with the mirror images, which is not good from both performance and redundancy view point. Example of "lvs -a -o lv_name,devices" after lvconvert: LV Devices lv0 lv0_mimage_0(0),lv0_mimage_1(0) [lv0_mimage_0] /dev/mapper/pv0(0) [lv0_mimage_1] /dev/mapper/pv1(0) [lv0_mlog] /dev/mapper/pv1(1) Shell script to reproduce the problem and the sample metadata is attached for reference. You can reproduce the problem with just executing the script without additional parameters. While this patch fixes the most simple case (i.e. the original LV is contiguous), there is another problem not yet fixed: if the original LV was split into multiple segments, the log device allocation only the PVs used for the first segment. Key to fix the another problem is avoiding all PVs in ah->parallel_areas for the log device allocation instead of the subset of it. There were attempts to fix it along with other allocation issues but not yet accpeted for some reasons. [PATCH LVM2 0/2] fix alloc anywhere and addition of disklog https://www.redhat.com/archives/linux-lvm/2006-September/msg00108.html [PATCH LVM2] (0/12) LVM2 allocation rewrites https://www.redhat.com/archives/lvm-devel/2006-October/msg00030.html I'm trying to find less intrusive approach to fix it. Thanks, -- Jun'ichi Nomura, NEC Corporation of America -------------- next part -------------- A non-text attachment was scrubbed... Name: lvconvert-use-build_parallel.patch Type: text/x-patch Size: 1242 bytes Desc: not available URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: lvm2-addlog-2PV.sh Type: application/x-sh Size: 1741 bytes Desc: not available URL: -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: lvm2-addlog-2PV.vg URL: