Minor error on disk with mirror by software

[WilliamSmith11]

Hi
I have a system hp9000 running hpux 11.00.
The machine is in cluster with other hp9000 same os version.

These machine are sharing an old ds2300 disk enclosure.

The problem is that the machine is slow for a specific process, all other process are running ok.

I have been looking for error messages, logs etc.

In the attachment there is more information about that.

If the problem is the disk drive how I replace the failed disk without lossing data or stopping the operation.

Regards

W.S

[Johnson Punniyalingam]

Hi,

Looking the attached file "you are suspecting Harddisk problem"

step1 :- dd if=/dev/dsk/c7t3d0 of=/dev/null bs=256k &
dd if=/dev/dsk/c8t3d0 of=/dev/null bs=256k &

(the both above commands output should have the same value of "records in & records out " if the value not tally bingo..! suspecting the faulty disk)

replace faulty disk " down-time may need if your 'logical volume are not mirrored" if mirrored

replace the faulty disk

vgreduce /dev/vg11 /dev/dsk/cxtxdx --> faulty disk

ioscan -fnC disk --> check for the new HW disk claimed
pvcreate -f /dev/dsk/cxtxdx
vgextend vg11 /dev/dsk/cxtxdx
vgchange -a y /dev/vg11
lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/cxtxdx
lvextend -m 1 /dev/vg00/lvol2 /dev/dsk/cxtxdx

or

wish to perform without lossing data or stopping the operation.(personal recommandation to move the package to another node)



your need add one more disk

pvcreate -f /dev/dsk/cxtxdx
vgextend vg11 /dev/dsk/cxtxdx
vgchange -a y /dev/vg11

man pvmove --> look man paged for more info

pvmove -n /dev/vg11/lvol1 /dev/dsk/c7t3d0 /dev/dsk/cxtxdx --> new disk
pvmove -n /dev/vg11/lvol2 /dev/dsk/c7t3d0 /dev/dsk/cxtxdx --> new disk

by performing the above steps all resding under faulty disks are been moved to newly replaced disk"lvols" under vg11

hope this helps

rgds,
Johnson

[Sandeep_Chaudhary]

here i can see disk utilization fr other disk also like c7t2d0, c7t1d0....


so r u going to replace all disk

post iostat when the particular program is not running and another output when the particular program is running.

[Ganesan R · Accepted solution]

Hi,

From the log, the disk in question is c7t3d0. Check the integrity of the disk by dd command. If any media errors you can replace the disk without lossing the data since you have mirror copy.

Looking at the VG11 details, there are two LV's and both are mirrored.Two ways you can replace the disk. Offline steps you should follow are,

First you should reduce the mirror from the disk c7t3do.
#lvreduce -m 0 /dev/vg11/lvol1 /dev/dsk/c7t3d0
#lvreduce -m 0 /dev/vg11/lvol2 /dev/dsk/c7t3d0

Then remove the disk from vg11
#vgreduce vg11 /dev/dsk/c7t3d0

Replace the disk and extend the vg

#pvcreate /dev/rdsk/c7t3d0
#vgextend vg11 /dev/dsk/c7t3d0

Extend the mirrors

#lvreduce -m 1 /dev/vg11/lvol1 /dev/dsk/c7t3d0
#lvreduce -m 1 /dev/vg11/lvol2 /dev/dsk/c7t3d0

#vgsync

You can also replace the disk online if disk enclosure supports. In that case no need to reduce the mirror and all. Follow the below steps.

#pvchange -a n /dev/dsk/c7t3d0 (Need OLR patches)
replace the disk
#vgcfgrestore -n vg11 /dev/dsk/c7t3d0
#pvchange -a y /dev/dsk/c7t3d0
#vgchange -a y vg11
#vgsync


Hope this helps.

[WilliamSmith11]

Thank you.
I will send output when is not running that particular process and other when it is.

W.S