topic Re: Replace disk/RAID in vg00 in Operating System - HP-UX

Replace disk/RAID in vg00

Nagaraja Dyava Setty — Sat, 14 Jul 2001 03:06:09 GMT

I inherited a problem regarding a K210 with HP-UX 11.0 unmirrored.

Basically, the machine has 2 internal disks (1x2GB, 1x18GB) and one old external disk array (w/ 3x2GB hot-swap disks) configured as RAID 5.

The vg00 consists of the the 2GB internal disk and the RAID configured as 1 4GB disk. Examining further, I found out that the 2GB internal disk contains lvol1 to lvol3 and the RAID contains the lvol4 to lvol9.

Now, the two of the disks in the RAID failed almost simultaneously.

What I have right now is a new 9GB internal disk.

Can I use this 9GB internal disk to take the place of the RAID in vg00? How do I recover the system settings?

Re: Replace disk/RAID in vg00

Patrick Wallek — Sat, 14 Jul 2001 03:21:23 GMT

Sounds like you may have a bit of a problem. Is the data in the external RAID array still available? Do you have any backups of anything? Possibly a make_recovery backup?

What I would do is this:

If you do have a make_recovery backup:
Install the 9GB internal disk. Boot off of the make_recovery tape and rebuild your system to use the 9GB drive as vg00.

If you don't have a make_recovery backup and the data on the array is still available, then download and install ignite/UX, make a make_tape_recovery backup and proceed as above.

If the data on the array is not available, you may not be able to do a whole lot.

Re: Replace disk/RAID in vg00

Nagaraja Dyava Setty — Tue, 17 Jul 2001 00:00:40 GMT

Patrick, seems I don't have a make-recovery tape and I only have a full system backup. Any suggestions on what I can do with what I have?

Re: Replace disk/RAID in vg00

Sridhar Venkataramu — Tue, 17 Jul 2001 22:05:26 GMT

i think this will be a time consuming process with some assumptions as i could not open your attachment..

firstly, you need to have following :
a. the device address for the 4 GB raid volume
b. use the 9gb internal disk - u must have the
device address for this.
(please note the addresses when system has booted)
c. you must have the latest vg config file in /etc/lvmconf/vg00.conf
(make backup copy before use)

1. restart the server in quorum override mode..
"hpux -lq" at isl>
2. perform a "vgreduce [-f] vg00 --> this will remove the raid volume from the vg, and destroy all volumes on it.
3. pvcreate [-F]
4. vgcfgrestore -n vg00 -o
5. vgchange -a y vg00
6. create new volumes on vg00 and new filesystems
7. mount the newly created volumes on the respective mount points and restore from backup

NOTE: create volumes on the new disk with the same volume names, else u may have to make changes to /etc/fstab file.
please verify switches for all commands. this should work.
best luck

sridhar

Re: Replace disk/RAID in vg00

Nagaraja Dyava Setty — Wed, 18 Jul 2001 01:48:58 GMT

Hi Sridhar,

The attachement I sent is the zipped nickel output for the machine involved. Perhaps you can help me better if you can open it. Can I send it to you directly?

From that nickel output, you'll notice that the logical volumes assigned as /var, /usr, and /opt are contained in the RAID.

Now as for your suggestion, in quorum override mode, will I be able to do a vgreduce to remove the RAID in vg00 even if the /var, /usr, and /opt are in the RAID?

thanks in advance,
edwin

Re: Replace disk/RAID in vg00

Sridhar Venkataramu — Wed, 18 Jul 2001 13:31:25 GMT

[NOTE: I have suggested a second option in the end.]
please send the attachment.

To add ..you wont need /var /opt /usr or /home, however what should be accessible for performing this is /etc, /sbin, all those directories on / . So the procedure should work.

once you do a vgreduce, check the following..
the device files for the volumes lvol4, lvol5..etc have been removed..comment out the entries in fstab for these lv(s).

and the entry for the 4gb raid pv is also gone from /etc/lvmtab. use "strings /etc/lvmtab" - this will list the vg(s) and respective pv(s) under it. (If the pv enrtry still remains, rename the lvmtab file and perform a vgscan. this will recreate the lvmtab file.)

[SECOND OPTION]

On the other hand, i think you can export the 18gb volume group.

perform a minimum install of the os on the 9gb.
restore your tape. But ensure to protect the lv/vg related files during restore. else, next boot the system will not come up. ( u may choose to retain the VG to LV to FS mapping from the old system.)

NOTE: You can try this first, even as u have the 2gb and the raid disks in its current state.

Re: Replace disk/RAID in vg00

Sridhar Venkataramu — Wed, 18 Jul 2001 14:46:36 GMT

addendum.. for option 2, you may not be able to export the vg(18gb), not to worry it can be imported manually.

after u r done with the os install on 9gb..
to activate the 18gb vg, do the following:
a. create a vg01 directory in /dev
b. mknod c /dev/vg01/group 64 0x01000n
=> 0x01000n : should be unique, use 0-9
for n
c. vgimport -v /dev/vg01 /dev/dsk/c?t?d?
d. vgchange -a y vg01
e. you will now have the volumes in 18gb available for mounting on respective mount points.. create the mount points with proper permissions and mount the volumes..