Hello,

Thanks for your reply.

Here is the results from my system:

Two VGs.

systemvg on /dev/sda4
datavg on /dev/sdb1

ls -la /dev/mapper

total 124 drwxr-xr-x�� 2 root root�� 4096 Sep 16� 2005 . drwxr-xr-x� 36 root root� 118784 Sep 16 01:49 .. crw-------�� 1 root root� 10, 63 Sep 16� 2005 control brw-------�� 1 root root 253,� 8 Sep 16� 2005 datavg-backup brw-------�� 1 root root 253,� 6 Jul 16 20:32 datavg-rootlv brw-------�� 1 root root 253,� 7 Jul 16 22:40 datavg-snk2lv brw-------�� 1 root root 253,� 0 Jun� 5 03:24 systemvg-optlv brw-------�� 1 root root 253,� 1 May 10 03:08 systemvg-rootlv brw-------�� 1 root root 253,� 4 Jun� 5 03:27 systemvg-temp brw-------�� 1 root root 253,� 2 Jun� 5 03:26 systemvg-tmplv brw-------�� 1 root root 253,� 3 Jun� 5 03:26 systemvg-usrlv brw-------�� 1 root root 253,� 1 Jun� 5 03:25 systemvg-varlv

df -h output is follows:

Filesystem�� Size� Used Avail Use% Mounted on /dev/root/rootlv�� 1008M� 255M� 702M� 27% / tmpfs�� 500M�� 24K� 500M�� 1% /dev/shm /dev/sda2�� 54M� 7.1M�� 44M� 14% /boot /dev/mapper/systemvg-optlv� � 3.0G� 607M� 2.4G� 20% /opt�� <--,�These filesystems and their
/dev/mapper/systemvg-tmplv�� 4.0G� 2.7G� 1.4G� 67% /usr�� <---�mapped devices are scrambled
/dev/mapper/systemvg-usrlv�� 2.0G� 442M� 1.6G� 22% /var�� <---�and I found this combination
/dev/mapper/systemvg-varlv� � 2.0G� 4.7M� 2.0G�� 1% /tmp�� <--'�by try-and-find !!
/dev/mapper/datavg-backup�� 69G�� 33M�� 69G�� 1% /mnt/backup /dev/mapper/datavg-rootlv �� 1020M� 261M� 760M� 26% /mnt/datavg-rootlv /dev/mapper/datavg-snk2lv� �� 4.0G� 2.7G� 1.4G� 68% /mnt/datavg-snk2�� <---- This filesystem is broken /dev/mapper/systemvg-rootlv � 2.0G� 4.7M� 2.0G�� 1% /mnt/systemvg-rootlv /dev/mapper/systemvg-temp�� 91G�� 63G�� 29G� 69% /mnt/systemvg-temp

dmsetup ls output is:

systemvg-temp� (253, 4) systemvg-usrlv (253, 2) systemvg-tmplv (253, 1) systemvg-rootlv�� (253, 5) systemvg-varlv (253, 3) datavg-backup� (253, 8) datavg-snk2lv� (253, 7) datavg-rootlv� (253, 6) systemvg-optlv (253, 0)

dmsetup table output is:

systemvg-temp: 0 190791680 linear 8:4 33554816 systemvg-usrlv: 0 8388608 linear 8:4 20971904 systemvg-tmplv: 0 4194304 linear 8:4 16777600 systemvg-rootlv: 0 2097152 linear 8:4 384 systemvg-varlv: 0 4194304 linear 8:4 29360512 datavg-backup: 0 104857600 linear 8:17 41943424 datavg-backup: 104857600 37830656 linear 8:17 274727296 datavg-snk2lv: 0 39845888 linear 8:17 2097536 datavg-snk2lv: 39845888 127926272 linear 8:17 146801024 datavg-rootlv: 0 2097152 linear 8:17 384 systemvg-optlv: 0 6291456 linear 8:4 10486144

LV Dsplay for /dev/datavg/snk2lv :

� --- Logical volume --- � LV Name�� /dev/datavg/snk2lv � VG Name�� datavg � LV UUID�� MCuj5G-XO1e-z3OE-BT9N-Lr5p-SbCO-3U8D4K � LV Write Access�� read/write � LV Status�� available � # open�� 1 � LV Size�� 80.00 GB � Current LE�� 20480 � Segments�� 2 � Allocation�� inherit � Read ahead sectors�� 0 � Block device�� 253:7

As you can see it is 80 GB but in df -h output, it is only 4 GB, and the contents of the filesystem� is something like the contents of /usr, I think a snapshot of /usr at the time when this error occured.

Also here are the vgdisplay -v output� and dmsetup info output....

Also here is the fdisk -l output, incase needed..

fdisk -l Disk /dev/sda: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes �� Device Boot�� Start�� End�� Blocks�� Id� System /dev/sda1�� *�� 1�� 5222�� 41945683+�� 7� HPFS/NTFS /dev/sda2�� 5223�� 5229�� 56227+� 83� Linux /dev/sda3�� 5230�� 5491�� 2104515�� 82� Linux swap / Solaris /dev/sda4�� 5492�� 19456�� 112173862+� 8e� Linux LVM Disk /dev/sdb: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes �� Device Boot�� Start�� End�� Blocks�� Id� System /dev/sdb1�� 1�� 19456�� 156280288+� 8e� Linux LVM

What I am trying to do is:

- At least get the directory contents of the filesystem /dev/datavg/snk2lv inorder to know what I have lost. Is it possible to get this with jfsutils ?? Any experience ?
- If there is a way to fix-up the device-mapper tables and get my filesystems back, it is ofcourse welcome.

Thanks in advance....

Fabian Herschel wrote:

You have a look which device path is used when mounting your both file
systems (using mount).
Than you can have a look at the major and minor device number of these
devices (using ls -la).
If these devices are using the same major/minor combination the kernel
assumes these devices
the be the same. This would show the effects you mentioned.

ls -la /dev/mapper/*
brw-------  1 root root 253, 3 Jun 21 16:09 /dev/mapper/rootvg-homlv
brw-------  1 root root 253, 2 Jun 21 16:09 /dev/mapper/rootvg-optlv

in this case rootvg-homlv has major 253 and minor 3, while rootvg-optlv
has major 253 and minor 2.

best regards
Fabian Herschel


Suleyman Kutlu schrieb:

Hello all,


I have an AMD-64 machine running SuSE 9.2. I have one SATA disk (for
now, will add another later on) and a VG on it. I have created some LVs.

Sometimes later, I realized that when I mount an LV (say lv_a) I see
the directory structure of another LV (say lv_b). If I issue a df -k,
I see a wrong size for lv_a, it is the size of lv_b. But in lvdisplay
output, the size for lv_a is correct.

The file systems on lv_a and lv_b is JFS.

/mnt is mounted as lv_b
/mnt2 is mounted as lv_a but has contents of lv_b


I thought that, filesystem structure is corrupted and started to work
on some filesystem level utilities, but later I see that,
another filesystem pair also got the same problem.


So I think it is a problem in device-mapper level, not the filesystem
level.

What can be the possible works to get what is wrong and how to fix ?
If the corruption is at filesystem level, do you have any experience
on JFS-utils ? I just want to see what was stored in lv_a, what I lost
in lv_a...


I am new at device-mapper, I don't have enough experience on it and I
do not want to loose everything while there is something that can be
recovered...

Any help is appreciated.

Thanks and regards..

* Suleyman Kutlu
* mailto: suleyman.kutlu@gmail.com

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