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After SLES10 SP3 update, san device merge to dm incomplete.

KuehnUl
Advisor

After SLES10 SP3 update, san device merge to dm incomplete.

Hello,

after an update from SLES10 SP1 to SP3 and the installation from HPDMmulitpath-4.4.0 package, no san device was visible with "multipath -ll" command.
After I removed all qla entry from /etc/modprobe.local.conf, the san devices was visible but the automatic upgrade from /dev/sd* to /dev/dm-* did not work completely. Three from four devices merged to the dm device, one not.

Is it possible to move the /dev/sdm device to a dm-device by shell commands?

Thanks for your support.

Best regards,

Uli


--- Physical volumes ---

PV Name /dev/sdm
PV UUID q3KwL5-Bu6f-CVTq-mm51-WJy6-W2CX-K5TkfG
PV Status allocatable
Total PE / Free PE 37119 / 0

PV Name /dev/dm-3
PV UUID fE3i2D-VwoQ-MZvG-PmHH-CGC6-YSnB-0o2V8Y
PV Status allocatable
Total PE / Free PE 37119 / 0

PV Name /dev/dm-2
PV UUID nQjKRH-YfI7-f1mx-iIr1-EGZl-m6Aw-dV8QB1
PV Status allocatable
Total PE / Free PE 37119 / 0

PV Name /dev/dm-1
PV UUID FgPVlq-qoQ2-xAHL-Uced-1ffo-Hlq2-JtSxAY
PV Status allocatable
Total PE / Free PE 37119 / 0
2 REPLIES
Matti_Kurkela
Honored Contributor

Re: After SLES10 SP3 update, san device merge to dm incomplete.

Please show the output of the following commands:

ls -l /dev/dm-* /dev/mapper /dev/mpath

dmsetup ls --tree

There are multiple ways to refer to DM-multipath devices, of which the /dev/dm-* filenames are the least informative.

When "vgscan" is run (for example, every time the system boots), LVM checks all the disk devices for LVM PV headers. If the same PV is seen through multiple paths, by default LVM chooses the first path it sees.

You can use /etc/lvm/lvm.conf to modify this behavior:

- You can use the "preferred_names" configuration keyword to make LVM prefer some types of devices over others. In this case, LVM should prefer the multipath devices over regular /dev/sd* devices.

- You can use the "filter" keyword to prevent LVM from scanning some devices at all.

The /etc/lvm/lvm.conf file has a lot of comments to describe the use of each keyword. There are even commented example configuration lines for some common cases.

After editing lvm.conf, run "vgscan -vv" to make the changes take effect immediately.

Remember that /etc/lvm/lvm.conf may be included in your initrd/initramfs file, so you may have to regenerate your initrd/initramfs to prevent LVM from using an old version when the system reboots.

Older versions of LVM2 (for example, a RHEL 4.0 system that has not been updated since original release) may not have the preferred_names keyword, but I think SLES10 SP3 is new enough to have both keywords available.

MK
MK
KuehnUl
Advisor

Re: After SLES10 SP3 update, san device merge to dm incomplete.

The system is not longer available, because we had to go back to SP1 at the end of the PMW for customer reason.

If I remeber right, there was no fourth /dev/dm-device. A reboot from the blade or the dm-daemon didn't solve the problem.

I think the problem is on the dm layer not on the lvm. But thanks for you new ideas, I will check this on the next update session.