From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Andreas Dilger Message-Id: <200104181815.f3IIF9JW030481@webber.adilger.int> Subject: Re: [linux-lvm] Strangenesses with snapshots, 0.9.1-beta6. In-Reply-To: <20010417234127.B3388@sistina.com> "from AJ Lewis at Apr 17, 2001 11:41:27 pm" Date: Wed, 18 Apr 2001 12:15:09 -0600 (MDT) MIME-Version: 1.0 Sender: linux-lvm-admin@sistina.com Errors-To: linux-lvm-admin@sistina.com Reply-To: linux-lvm@sistina.com List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-lvm@sistina.com AJ writes: > Are you sure those files were in a consistant state when you took the > snapshot? You really need to get your file system into a consistant state, > otherwise the metadata could be partially written out when the snapshot is > made. There are hooks put into the 2.4x series kernels for ReiserFS to > allow it to prepare for snapshots...but i don't think ext2 uses any > mechanisms like this. I don't know a whole lot about it, but that's what it > looks like to me. Well, before the LVM snapshot is created, it does a full sync of the device, so the amount of metadata that could be out-of-date would be very small (if any). Granted, there is a possibility that the original data is corrupt, but Vegard reports everything OK on the original filesystem. I assume that e2fsck -f on the unmounted /dev/vg/nhome works OK? > > cp: cannot stat `/mnt/backup/vegard/Mail/unix/openldap-general/314': Input/output error > > cp: cannot stat `/mnt/backup/vegard/Mail/unix/openldap-general/315': Input/output error > > cp: cannot stat `/mnt/backup/vegard/Mail/unix/openldap-general/316': Input/output error > > cp: cannot stat `/mnt/backup/vegard/Mail/unix/openldap-general/317': Input/output error > > > > [ *** This is another strangeness *** ] > > middagspynten:/mnt/backup/vegard/Mail/unix/openldap-general# ls -l > > ..... > > -rw------- 1 vegard vegard 3454 Dec 11 1999 309 > > -rw------- 1 vegard vegard 4530 Sep 9 1999 31 > > -rw------- 1 vegard vegard 4147 Dec 11 1999 310 > > -rw------- 1 vegard vegard 3294 Dec 11 1999 311 > > -rw------- 1 vegard vegard 3452 Dec 11 1999 312 > > -rw------- 1 vegard vegard 5775 Dec 13 1999 313 > > -rw------- 1 vegard vegard 3292 Dec 22 1999 318 > > -rw------- 1 vegard vegard 4318 Dec 22 1999 319 > > -rw------- 1 vegard vegard 4384 Sep 11 1999 32 The same files with IO errors are those missing from the directory listing. Based on the file timestamps, I would assume that these files have not been changed in a long time, so it is not a metadata consistency issue. Cheers, Andreas -- Andreas Dilger \ "If a man ate a pound of pasta and a pound of antipasto, \ would they cancel out, leaving him still hungry?" http://www-mddsp.enel.ucalgary.ca/People/adilger/ -- Dogbert