Please disregard. I need to read the whole email first..... > -----Original Message----- > From: Little, Chris [mailto:Chris.Little@okdhs.org] > Sent: Thursday, April 15, 2004 10:40 AM > To: 'LVM general discussion and development' > Subject: RE: Bug when creating snapshots on lvm on s390 > > > This is a known issue. I have a bug open with IBM who in > turn has opened > one with SUSE : > > --------------- > > This is a short update from SuSE LVL3 folks. > > his is a short status about the work that has been done to > fix this bug. > > Since the bug has been posted, different SuSE developers have > been working > on that. > > They have found a way to track the problem: > "by simply deleting and rewriting 200 MB to the first > original volume after > creating the backups caused corruption on the second original volume." > > <citat> of one developer > > I have finally been able to reproduce it, on s390l2. > > I have set up LVM similar to the setup described in the bug > report (three > volume groups, several striped volumes on vg01), created two ext3 > filesystems > (/dev/vg01/lvol[12]), filled them up with several copies of > /opt/kde3, then > made backups (/dev/vg01/backup[12]) with the filesystems mounted as > described > above, then mounted those backups read-only. > > No corruption on any volume so far. > > After deleting some kde3 copies on /dev/vg01/lvol1 and > copying them back > again > with different names, seemingly random corruption reared its > ugly head on > _all_ volumes. Try "for i in /mnt/*/? /mnt/*/?? /mnt/*/??? ; > do diff -r > /opt/ > kde3 $i ; done" (ignore the dangling symlinks). > /var/log/messages may be > worth > a look as well. > > </citat> > > Afterwards we have contacted IBM Boeblingen, and they have > been also able to > reproduce the issue in the vanilla LVM-code. Even in version 1.0.7. > > We tried to reproduce it on x86, but it was not possible, on > PPC we do not > know yet. > > Summary: > > The corruption we see on S/390 can be caused anywhere in the kernel, > starting > from the memory subsystem to the iobuf on S/390 (suspection of Andrea > Arcangeli) to the buffer header code within LVM(suspection of Martin > Schwidefsky) to the remapping of blocks within LVM-snapshot > specific code > paths(and there are many) inside LVM including LV locking issues and > list-handling for the exception table which seems to be the > instance where > the > LVM code works out the snapshot-specific block mapping. > > By next week, you will hear from me; our developers are > intensively working > on that issue. > > With kind regards, > > Thomas Fenton > Staff Software Engineer > IBM Integrated Technical Services > Linux and NUMA-Q support > > -----Original Message----- > > From: Ihno Krumreich [mailto:ihno@suse.de] > > Sent: Thursday, April 15, 2004 5:42 AM > > To: linux-lvm@redhat.com; Mauelshagen@redhat.com > > Cc: Bernhard Kaindl; Uwe Drechsel; Ulrich Hecht > > Subject: Bug when creating snapshots on lvm on s390 > > > > > > Hi, > > > > we have a filecorruption on a LVM-Volume when a > > snapshot is created. This Problem seem to occur only > > on s390 (31-Bit mode). > > > > are there any known issues when using snapshots on lvm on s390? > > > > regards > > > > Ihno Krumreich > > > > How to create the bug: > > > > - Create three volume groups, which are striped over multiple > > physical disks (9 x 2GByte). > > - use the second volume group to create a logical volume > > - create a file system on this LV (problem occurs with ext2, > > ext3, reiserfs) > > and put data in the filesystem > > - create a snapshot of this LVOL > > - the data on the original LVOL are corruptet > > > > - It is important that the filesystem is mounted read/write > > If it is only mounted readonly and the snapshot is > > created the corruption does not occur. > > > > > > Machine setup: > > > > S390 31-Bit with SUSE linux Enterprise Server 8 Service Pack 3 > > Machine has 2 Gbyte RAM and 9 Model-3 DASD for the LVM. > > > > SLES8 has LVM Version 1.0.5 with IBM patches for multipath support. > > > > To exclude that Kernel modification from SUSE/IBM cause the > > problem IBM has testet it with the vanilla kernel 2.4.21 and > > LVM Version 1.0.7 and the problem is the same. > > > > At SUSE we tried to reproduce the problem on x86, but without > > success (kernel 2.4.21 with lvm 1.0.5). > > > > In the attached tar-ball is a file which showes the corruption > > starting at byte 0xc000 with a length of 0x1000 Bytes. > > > > > > -- > > Best regards/Mit freundlichen Grüßen > > > > Ihno Krumreich > > > > "Never trust a computer you can lift." > > -- > > Ihno Krumreich ihno@suse.de > > SuSE Linux AG Projectmanager S390 & zSeries > > Maxfeldstr. 5 +49-911-74053-439 > > D-90409 Nürnberg http://www.suse.de > > > > _______________________________________________ > > linux-lvm mailing list > > linux-lvm@redhat.com > > https://www.redhat.com/mailman/listinfo/linux-lvm > > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ > > > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ > _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
