topic Problem restoring a replaced disk in Operating System - HP-UX

Problem restoring a replaced disk

Michael D. Zorn — Fri, 21 Jul 2006 13:21:14 GMT

I only do this once every 4 or 5 years, so I have to start over every time.

We just replaced a failed disk. I'm using the "When Good Disks Go Bad" doc from HP.

So far, I have
#vgcfgrestore -n /dev/vgfam /dev/rdsk/c9t5d0
- - OK
#vgchange -a y /dev/vfam
- - OK
but
#mount /data05
- - not a hfs file system
OK - that probably means the disk wasn't initialized. So I tried
#newfs -F hfs /dev/rdsk/c9t5d0
- - /dev/rdsk/c9t5d0 is a logical volume device

then
#pvcreate /dev/rdsk/c9t5d0
- - already belongs to a VG

#vgreduce /dev/vgfam /dev/dsk/c9t5d0
- - could not be removed ... some of its physical extents are still in use

I'm in single-user mode, the FS are not mounted on c9t5d0.

pvdisplay shows extents are there for all the FS that should be.

#vgdisplay shows the lvols in that VG as "available/syncd", and size not zero.

I'm probably overlooking some small but essential step, but I don't know what it is.

Re: Problem restoring a replaced disk

Patrick Wallek — Fri, 21 Jul 2006 13:23:36 GMT

Is it an HFS or a VxFS filesystem?

What if you do:

mount -F vxfs /data05

Re: Problem restoring a replaced disk

Michael D. Zorn — Fri, 21 Jul 2006 13:58:16 GMT

It is a hfs sytem.
It's also HP-UX 10.02, so 'pvchange' doesn't have '-a'

Re: Problem restoring a replaced disk

Albert_31 — Fri, 21 Jul 2006 23:41:05 GMT

hello Micheal,

Can you post the following

# vgdisplay -v
# strings /etc/lvmtab
# vgcfgbackup -f /tmp/vgfam.conf /dev/vgfam
# vgcfgrestore -l -f /tmp/vgfam.conf
# vgcfgrestore -l -f /etc/lvmconf/vgfam.conf
# cat /etc/fstab

so that we get a good idea of the current scenario and help you with the disk replacement.

regards

albert

Re: Problem restoring a replaced disk

Torsten. — Sat, 22 Jul 2006 06:59:00 GMT

I assume the disk was not mirrored.

If you replaced the disk and the config was restored to it (vgcfgrestore), don't do a pvcreate!

After the vgchange command, just create a new file system and mount it. Now you should restore the data from the backup.

Re: Problem restoring a replaced disk

Michael Duthie — Mon, 24 Jul 2006 03:17:29 GMT

"#mount /data05
- - not a hfs file system
OK - that probably means the disk wasn't initialized. So I tried
#newfs -F hfs /dev/rdsk/c9t5d0
- - /dev/rdsk/c9t5d0 is a logical volume device"

You have "newfs'ed" the physical volume no the logicel volume.

the process is

pvcreate -f /dev/rdsk/cXtXd0

Restore the volume group information.
vgcfgrestore -n /dev/vgXX /dev/rdsk/cXtXd0

Activate the volume group with the new disk.
vgchange -a y /dev/vgXX

Make a new file system on the associated lvols on the volume group.
newfs -F vxfs /dev/vgXX/rlovlX (JFS file system)

Mount the file system or systems.
mount -a

Do a pvdisplay /dev/dsk/c9t5d0 to see what is on the disk. You will see the locical volumes that you restored using vgrestore. Your newfs of the disk "/dev/rdsk/c9t5d0" has probably trashed it.

Re: Problem restoring a replaced disk

Michael D. Zorn — Mon, 24 Jul 2006 22:02:09 GMT

Torsten says don't do a pvcreate if I ran vgcfgrestore - I did... Michael Duthie says do - I assume he means if I didn't.

I think what may be getting me in trouble is that /etc/fstab has entries for the FS that were on the disk. /etc/mnttab does not.

Albert asks for output from volume mgmnt commands - I'll attach it.

Re: Problem restoring a replaced disk

rayche — Mon, 24 Jul 2006 22:27:58 GMT

You do not need to be in troule about fstab and mnttab, fstab is used to mount file system automatically when boot system,and mnttab will display which file system is being mounted currently, so pls do according to Tosten's advice, and make sure the lv name and mount point is same as /etc/lvmtab, then run mount all

Re: Problem restoring a replaced disk

Albert_31 — Mon, 24 Jul 2006 22:43:54 GMT

Hello Michael,

Checked the data collected and agree with Torsten.. the volume group vgfam is not mirrored and all logical volumes which have their LE/PE's on the disk c9t5d0, have they data lost and you need to restore them.

You can check this using the

# lvdisplay -v /dev/vgfam/ | more

You will notice that all LVOL's which have LE/PE on the c9t5d0 will not be mountable or accessible.

So basically we have to follow the data restoratin steps

# vgcfgrestore -n /dev/vgfam /dev/rdsk/c9t5d0
This will put the LVM headers and LV configs onto the disk. Next you have to do the newfs followed by mounting the LV on the mount points and then restoring data.

# newfs -F -o /dev/vgfam/r

# restore the data from backup.

Regards

Albert

Re: Problem restoring a replaced disk

Michael Duthie — Tue, 25 Jul 2006 02:34:21 GMT

"Torsten says don't do a pvcreate if I ran vgcfgrestore - I did... Michael Duthie says do - I assume he means if I didn't."

Torsten mean dont pvcreate after a vgrestore, you will blow away what you have just restored.

can you attached a pvdisplay of the disk, all looks in order. a "newfs /dev/vgfam/rlvol3", 4, 5, & 16 may be enough to fix.

Re: Problem restoring a replaced disk

Torsten. — Tue, 25 Jul 2006 02:45:59 GMT

Exactly. If you run the pvcreate after the vgfgrestore you will overwrite the config.

I don't know if your wrong command wrote anything
#newfs -F hfs /dev/rdsk/c9t5d0

but i would try to start over beginning with the vgcfgrestore command. Make sure this time you create the filesystem on the LVOL, e.g.

newfs -F hfs /dev/vgfam/rlvolx

Re: Problem restoring a replaced disk

Albert_31 — Tue, 25 Jul 2006 02:53:25 GMT

Hello Michael,

There is nothing to there on the disk to be lost when you did a newfs on the disk, nothing to worry (I guess )

get started with.. (as a precaution..take a data backup of all data in vgfam as well, before you proceed.

vgcfgrestore ->newfs -> mount -> restore from backup..

regards

Albert

Re: Problem restoring a replaced disk

Michael D. Zorn — Tue, 25 Jul 2006 13:05:54 GMT

Thanks to all - it's finally working.

It looks like one of my problems was that the man page for 'newfs' shows in the examples

newfs /dev/rdsk/c1d0s2

when I really needed to do

newfs /dev/vgfam/rlvolN

(That, and doing a few other things out of sequence.)

The disk failed suddenly, over a weekend. I didn't see anything in the syslog files.

As usual, every time one of these things happens, I have to revise my backup plan.

One of the benefits of having an old system (K200 PA-RISC, HP-UX 10.01) is that we have 8 small disks (2GB each), so that when one goes down, there's still a lot left.