Date: Thu, 21 Sep 2006 18:18:45 -0400 From: James Lauser <james@jlauser.net> To: freebsd-fs@freebsd.org Subject: Re: Snapshot corruption on 6.1/amd64 Message-ID: <8ED0D713-1023-4246-BCFE-FE318A287866@jlauser.net> In-Reply-To: <4512F957.2090205@centtech.com> References: <854C78DB-2099-4DA5-9E3B-F30D6947C532@jlauser.net> <4512F957.2090205@centtech.com>
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fsck -y shows no issues with /raid.
Quotas are not enabled. The file system is 325 GB.
-- James L. Lauser
james@jlauser.net
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On Sep 21, 2006, at 16:43 , Eric Anderson wrote:
> On 09/21/06 14:59, James Lauser wrote:
>> Hello.
>> I've been having some trouble with snapshots on my FreeBSD 6.1/
>> amd64 system. Basically, I have this system set up with a 3ware
>> RAID card and several disks, and use it to collect backups from
>> my other FreeBSD server (sparc64) and three Macs via rsync..
>> Every night, I have a script generate a snapshot of the RAID's
>> file system, and those snapshots are kept on the system for one
>> week before being removed (i.e. there are always 7 snapshots
>> present on the system), so I can recover files that were
>> accidentally removed or changed.
>> The problem is that when a large number of files are removed or
>> changed on the file system, the corresponding files in the
>> snapshot get corrupted. This, obviously, makes the snapshots
>> quite useless.
>> After some searching, I've found a bug report filed last year
>> that describes this problem exactly, though the log of that
>> report does not suggest that anything has been done with it.
>> That report is at http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/
>> 90512
>> Any help would be greatly appreciated. A test I ran showing the
>> problem, plus the output of uname -a and dmesg.boot is attached.
>> Thanks in advance.
>
>
>> Sledge# cd /raid
>> Sledge# touch foo
>> Sledge# ls -l foo
>> -rw-r--r-- 1 root wheel 0 Sep 18 14:07 foo
>> Sledge# mksnap_ffs /raid /raid/.snap/snap
>> Sledge# rm foo
>> Sledge# mdconfig -a -t vnode -f /raid/.snap/snap -u 4
>> WARNING: opening backing store: /raid/.snap/snap readonly
>> Sledge# mount -r /dev/md4 /mnt
>> Sledge# cd /mnt
>> Sledge# ls -l foo
>> ls: foo: Bad file descriptor
>> Sledge# Sledge# Sledge# Sledge# uname -a
>> FreeBSD Sledge.jlauser.net 6.1-RELEASE-p6 FreeBSD 6.1-RELEASE-p6
>> #4: Wed Sep 6 23:30:56 EDT 2006 root@Sledge.jlauser.net:/usr/
>> obj/usr/src/sys/GENERIC amd64
>
> Hmm.. Interesting, it seems to work fine for me:
>
> [root@neutrino /tmp]# dd if=/dev/zero of=TESTDISK bs=1m count=100
> 100+0 records in
> 100+0 records out
> 104857600 bytes transferred in 3.390829 secs (30923882 bytes/sec)
> [root@neutrino /tmp]# mdconfig -a -t vnode -f ./TESTDISK
> md0
> [root@neutrino /tmp]# newfs -U /dev/md0
> /dev/md0: 100.0MB (204800 sectors) block size 16384, fragment size
> 2048
> using 4 cylinder groups of 25.02MB, 1601 blks, 3264 inodes.
> with soft updates
> super-block backups (for fsck -b #) at:
> 160, 51392, 102624, 153856
> [root@neutrino /tmp]# mount /dev/md0 /mnt
> [root@neutrino /tmp]# touch /mnt/foo
> [root@neutrino /tmp]# mksnap_ffs /mnt/ /mnt/.snap/snap
> [root@neutrino /tmp]# mdconfig -a -t vnode -f /mnt/.snap/snap
> WARNING: opening backing store: /mnt/.snap/snap readonly
> md1
> [root@neutrino /tmp]# mount -r /dev/md1 /mnt2
> [root@neutrino /tmp]# cd /mnt2
> [root@neutrino /mnt2]# ls -l foo
> -rw-r--r-- 1 root wheel 0 Sep 21 15:37 foo
> [root@neutrino /mnt2]#
>
>
> Can you unmount /raid, and do an fsck -y /raid and make sure it's
> clean? Also - are you using quotas? How big is the filesystem?
>
> Eric
>
>
>
>
> --
> ----------------------------------------------------------------------
> --
> Eric Anderson Sr. Systems Administrator Centaur
> Technology
> Anything that works is better than anything that doesn't.
> ----------------------------------------------------------------------
> --
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