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Re: LSM: Reintroducing a dsk to LSM

 
Carl Schelin
New Member

LSM: Reintroducing a dsk to LSM

OS: Tru64 5.1b

We had a disk generating errors that was under LSM control (disk06 -> dsk6). I had the disk replaced however the backup the DBAs created isn't working. They'd like to bring the disk back to see if they can get some of the data (there were four databases on the disk).

The disk was a single disk in a single volume.
dm disk06 dsk6 sliced 4096 71127888 -

v u02 fsgen ENABLED ACTIVE 35651584 SELECT -
pl pl-02 u02 ENABLED ACTIVE 35651584 CONCAT - RW
sd disk06-01 pl-02 disk06 0 35651584 0 dsk6 ENA

I have the disk back in the system but can't find a command that would let voldisk see dsk6 as a LSM controlled disk.

I'm thinking voldisksetup -i dsk6 would actually work since it's the data in the public area that I'm trying to recover and the metadata in the private area doesn't match the configuration now.

Or, could I just bring the public slice under advfs domain control (would it overwrite something) and just mount it?

I have several things I can try if it didn't blow the information on the public disk away.

Thanks for any help.

Carl Schelin
4 REPLIES 4
Manju R
New Member

Re: LSM: Reintroducing a dsk to LSM

Hi,

I'm not sure of the steps that were followed when the disk was replaced and the volume was recovered from the backup.

I'm trying to provide a solution based on the following assumption,
The replaced disk did not work as expected, thus the disk was removed and the error prone disk was put back.

If this is the case, run the below 2 commands. I'm not sure whether they succeed as there is no mention of the type of errors that were being reported by the disk.
Presuming that the disk had a temporary failure please run,

#voldctl enable
(This command scans all known disks to ensure disk is available)

#volrecover -sb disk_name
(In this case disk_name is dsk6 , performs volume recovery operations by starting disabled volumes and doing the recovery operation in the background)

Sincerely,
Manju
Kapil Jha
Honored Contributor

Re: LSM: Reintroducing a dsk to LSM

Hello ,
How did you remove the disk??/
did you use -k(to keep) option while removing disk.
If yes,then you may use volrecover -sb.

Did you recently run volsave???
Otherwise I think it should work if we add this dsk6 like normal method.
Hope this would help abit.
BR,
Kapil
I am in this small bowl, I wane see the real world......
Carl Schelin
New Member

Re: LSM: Reintroducing a dsk to LSM

Thanks for the replies.

Since it was a single disk being managed by LSM, we didn't see a reason to bring the replacement disk back under LSM control. So we removed the configuration from LSM and then put the new disk in the machine. I recreated the domain and fileset then mounted it for the DBAs to use.

The old disk was generating a lot of timeouts when trying to access data. According to HP support, there were physical errors on the disk too. But it appeared to return the data eventually. So we ran a tar command on the directory over the weekend to try and save the files. When the DBAs restored the tar file, the files were extracted however the data was corrupt.

After some discussion, we decided to try and put the old disk back in and see if we could bring it back under LSM control without losing the data in the public area. A last ditch effort if you will.

I did a lot of research yesterday to locate something that might do the trick but wasn't able to find anything. At the end of the day, the other admin here who has a lot more experience with these systems and I tried to just rebuild the volume.

The binary error log had 20 or so errors in the logs from the time I put the disk back in until the end of the day. At one point, when we were working on the volume, the disk errored out again and we had to delete the volume information and start over.

We eventually got the volume recreated however the data was not accessible.

Thanks for taking a look at the problem and for the replies.

Carl
Carl Schelin
New Member

Re: LSM: Reintroducing a dsk to LSM

Basically we've passed the point that replies would be helpful, at least in this case. Thanks again for taking the time to read and reply.

Carl