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Failed disk (mirrored)

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Martin Robinson
Frequent Advisor

Failed disk (mirrored)

I am sure this question has been asked and answered dozens of times, but I can't find a relevant posting.

We have a Jamaica array, and a disk which is mirroed has failed. It shows as NO_HW in ioscan.

Should I attempt to lvreduce -m0 on the logical volumes using this disk, then vgreduce to remove it from the volume group?

I don't want to even try if there is a chance of screwing up the live, running production database!
James R. Ferguson
Acclaimed Contributor

Re: Failed disk (mirrored)

Hi Martin:

The Software Recovery Handbook, found via the Knlwledge Trees link, offers appropriate recovery procedures in the LFM chapter (#16):


Stefan Farrelly
Honored Contributor

Re: Failed disk (mirrored)

No need to reduce it, simply replace the drive with a new one the same size, then;

1. vgcfgrestore -n /dev/rdsk/
2. vgchange -a y
3. vgsync

Thats it. If its a bootable drive run mkboot on it afterwards. If step 1. fails run another ioscan first so the drive shows as CLAIMED (and not NO_HW).

Im from Palmerston North, New Zealand, but somehow ended up in London...
Martin Robinson
Frequent Advisor

Re: Failed disk (mirrored)

James, that link doesn't work for me - Cannot Log in. Tried searching for Software Recovery Handbook and swrec - nothing promising there )mostly MPE docs)
James R. Ferguson
Acclaimed Contributor

Re: Failed disk (mirrored)

Hi (again) Martin:

You must be logged into the ITRC. Go to Maintenance and Support -> Navigate Knowledge Trees (under "self-solve tools") -> HP-UX Software Recovery Handbook.


Peter Weibbrecht
Occasional Advisor

Re: Failed disk (mirrored)

The way stefan said is the easiest one.
After removing the bad disk, don't forget an ioscan -fnCdisk.
In some cases ( if the disk is not complete failed ) the os will not notice that the disk is replaced. This can produce some strange effects.
after ioscan inster the new disk, and then do the rest ( vgcfgrestore, vgchange, vgsync and mkboot )
Thats all.
.... not this machine!!!
Martin Robinson
Frequent Advisor

Re: Failed disk (mirrored)

Does the vgchange -a y imply that the volume group is at some stage NOT activated?

Currently the system is running, and I don't want to stop the application (dismount file systems or deactivate volume groups) unless necessary.

# vgdisplay -v vg01
--- Volume groups ---
VG Name /dev/vg01
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 2
Open LV 2
Max PV 16
Cur PV 2
Act PV 2
Max PE per PV 2171
PE Size (Mbytes) 4
Total PE 4340
Alloc PE 4250
Free PE 90
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0

--- Logical volumes ---
LV Name /dev/vg01/lvol17
LV Status available/stale
LV Size (Mbytes) 1500
Current LE 375
Allocated PE 750
Used PV 2

LV Name /dev/vg01/lvol18
LV Status available/stale
LV Size (Mbytes) 7000
Current LE 1750
Allocated PE 3500
Used PV 2

--- Physical volumes ---
PV Name /dev/dsk/c5t4d0
PV Status unavailable
Total PE 2170
Free PE 45

PV Name /dev/dsk/c5t0d0
PV Status available
Total PE 2170
Free PE 45

Paula J Frazer-Campbell
Honored Contributor

Re: Failed disk (mirrored)

Attached here:-

If you can spell SysAdmin then you is one - anon
Steven E. Protter
Exalted Contributor

Re: Failed disk (mirrored)

The vgchange command above will activate a volume group that is not already activated.

It will not shut down the volume groupt, that happens in other steps of the earlier posts in this thread.

A vgchange -a n /dev/vg## command will deactivaate a volume group.

Steven E Protter
Owner of ISN Corporation

Re: Failed disk (mirrored)

Hello paula,
I want to download the whole Software Recovery Handbook,instead of the individal chaper,could you please attach it for me ? than you.