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How to remove a disk from vg00

 
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Domenico Viggiani
Super Advisor

How to remove a disk from vg00

Hi,
on a Itanium2 box with HP-UX B.11.2,3 vg00 has two physical volumes; I don't like this situation because a single fail can destroy the whole system. Is there a safe method to remove a disk from vg, without reinstalling the system?
Machine was recently installed and I can suppose that there is no much data.
Another question: to mirror system disk, do I need Mirror/UX as in the RISC world?

Thanks in advance
Domenico Viggiani
21 REPLIES 21
Mohanasundaram_1
Honored Contributor

Re: How to remove a disk from vg00

Hi Domenico,

It depends on how the disks have been utilised within the vg. I would presume that the OS is only in 1 disk and the other part contains data.

In such a case, you can backup the data, remove the lVs on that disk, vgreduce and then create a new VG and lVs and then restore the backup.

If your concern is only about the system not booting in case of the data disk failure, then make the bootstring as "hpux -lq".

This will make the VG activated without quorum being present.

With regards,
Mohan.
Attitude, Not aptitude, determines your altitude
Domenico Viggiani
Super Advisor

Re: How to remove a disk from vg00

No, I have no data, there is only OS.
vg00 has two physical disks and I'd like to remove one disk without reinstalling.
Lorenzo Facello
Valued Contributor

Re: How to remove a disk from vg00

Hi,
have you any data on the second disk???
If the disk is empty you can simply do a
vgreduce /dev/dsk/disk2

check this linf for the itanium mirror:
http://h21007.www2.hp.com/dspp/tech/tech_TechSingleTipDetailPage_IDX/1,2366,5343,00.html


Hope this helps
L.F

Mohanasundaram_1
Honored Contributor

Re: How to remove a disk from vg00

Hi Domenico,

Ok, Lets see what we got here. Can you provide the pvdisplay -v

and

pvdisplay -v

This will make us understand how the filesystems are distributed. Please post it and we can get started.

WIth regards,
Mohan.
Attitude, Not aptitude, determines your altitude
Pete Randall
Outstanding Contributor

Re: How to remove a disk from vg00

Domenico,

Rather than removing the second disk, I would suggest that you first purchase MirrorDisk/UX and then use the second disk to mirror your root logical volumes.


Pete

Pete
Domenico Viggiani
Super Advisor

Re: How to remove a disk from vg00

Mohanasundaram, here are two 'pvdisplay' output.

Thank you
Enrico P.
Honored Contributor
Solution

Re: How to remove a disk from vg00

Hi Domenico
Seem you have two disks in mirror, this situation is ok for high availability.
Verify both of the disks are boot disks with the "lvlnboot -v" command and that the command "lifcp :AUTO -" give you the "hpux -lq" result for the both disks.
Can you send the "vgdisplay -v vg00", the "lvlnboot -v", lifcp :AUTO -" and the "setboot" output?

Enrico.
Mohanasundaram_1
Honored Contributor

Re: How to remove a disk from vg00

HI,

I see that you have already mirrored the lvols on the disk. So you need not worry.

Verify if you are able to boot from both the disks. As I had mentioned earlier, the boot string should be "hpux -lq".

This should take care of it.

With regards,
Mohan.
Attitude, Not aptitude, determines your altitude
Domenico Viggiani
Super Advisor

Re: How to remove a disk from vg00

Sorry but I'm not so sure that two disks are already mirrored. vg capacity is the sum of single disks capacity:

# vgdisplay -v vg00
--- Volume groups ---
VG Name /dev/vg00
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 8
Open LV 8
Max PV 16
Cur PV 2
Act PV 2
Max PE per PV 4356
VGDA 4
PE Size (Mbytes) 32
Total PE 8692
Alloc PE 958
Free PE 7734
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0

--- Logical volumes ---
LV Name /dev/vg00/lvol1
LV Status available/syncd
LV Size (Mbytes) 320
Current LE 10
Allocated PE 20
Used PV 2

LV Name /dev/vg00/lvol2
LV Status available/syncd
LV Size (Mbytes) 4096
Current LE 128
Allocated PE 256
Used PV 2

LV Name /dev/vg00/lvol3
LV Status available/syncd
LV Size (Mbytes) 512
Current LE 16
Allocated PE 32
Used PV 2

LV Name /dev/vg00/lvol4
LV Status available/syncd
LV Size (Mbytes) 224
Current LE 7
Allocated PE 14
Used PV 2

LV Name /dev/vg00/lvol5
LV Status available/syncd
LV Size (Mbytes) 32
Current LE 1
Allocated PE 2
Used PV 2

LV Name /dev/vg00/lvol6
LV Status available/syncd
LV Size (Mbytes) 2944
Current LE 92
Allocated PE 184
Used PV 2

LV Name /dev/vg00/lvol7
LV Status available/syncd
LV Size (Mbytes) 2592
Current LE 81
Allocated PE 162
Used PV 2

LV Name /dev/vg00/lvol8
LV Status available/syncd
LV Size (Mbytes) 4608
Current LE 144
Allocated PE 288
Used PV 2


--- Physical volumes ---
PV Name /dev/dsk/c3t2d0s2
PV Status available
Total PE 4346
Free PE 3867
Autoswitch On

PV Name /dev/dsk/c2t1d0s2
PV Status available
Total PE 4346
Free PE 3867
Autoswitch On