Remirror root disk in hpux11.23 IA64

[Trng]

Hi,

i have been told to install few software on my hpux 11.23 IA64 machine..for precaution i have split my mirroed root disk and install softwares successfully.now i have remirror it again the root disks ..below steps is ok ?

1--vgextend vg00 /dev/dsk/c1t1d1s2
2-lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/c1t1d1s2 and do the same for all other lvols

[Torsten.]

How did you "split" the mirror?

Procedures are here (appendix):

http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad_WP.pdf

[sujit kumar singh]

Hello Trng,


did you happen to split the Mirror of the root disk using the lvsplit command or exactly what did you do earlier like did yoiu simply pulled the disk out or you did lvreduce and vgreduce.
please tell in detail.
regards
sujit

[Suraj K Sankari]

Hi Trng,

>>i have split my mirroed root disk and install softwares

How you split can you please let us know that will help us to help you.

Suraj

[sujit kumar singh]

Hi
assuming that you have done a proper lvsplit of the root VG LVs that had been mirrored prior to your activity then you would be having the Split LVs that might have been created as a result of the lvsplit command.

the invocation of the lvsplit command as on a mirrored LV say /dev/vg00/lvol4 shall happen to result in creation ofthe solit lv named as default as /dev/vg00/lvol4backup

#lvsplit -s /dev/vg00/lvol4

this shall unmirror the LV /dev/vg00/lvol4 and create an LV named as /dev/vg00/lvol4backup.


do the tasks on the Orig LV and/or can use mount the /dev/vg00/lvol4backup and take a backup and do a merge of this with the orig LV that is /dev/vg00/lvol4 using the lvmerge command as follows:

#lvmerge /dev/vg00/lvol4backup /dev/vg00/lvol4

this shall merge the two LVs and sync them with the source of current data as as /dev/vg00/lvol4.

Refer to the appendix of When_Good_Disks_Go_bad

http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad_WP.pdf

and the manpages of the command lvsplit(1M) and lvmerge(1M).

http://docs.hp.com/en/B2355-60130/lvsplit.1M.html

http://docs.hp.com/en/B2355-60130/lvmerge.1M.html

regards
sujit

[Trng]

Dear All,

i guess i made a blunter mistake.becaz i split the mirror using lvreduce -m 0 and then vgreduce it.....how to remirror it and let m know how split the mirror (i am in remote site,so i cant remove unplug one of the wkg root HDD)


rgds
trng

[sujit kumar singh]

Hi


No issues.

1) replug the removed HDD
2)ioscan
3)insf -eCdisk
4)ioscan -fnCdisk - to see if that has come.


and do remirror
vi /tmp/pdf
3
EFI 500MB
HPUX 100%
HPSP 400MB

save and exit

make sure that the three ptns are same size as on the Current Disk.
removed disk is say cXtYdZ

#idisk -w -f /tmp/pdf cXtYdZ
#insf -eH

#ioscan -fnCdisk
#vi /tmp/auto
boot vmunix -lq
save and exit
#efi_fsinit -d /dev/rdsk/cXtYdZs1
#pvcreate -B /dev/rdsk/cXtYdZs2
#mkboot -e -l /dev/rdsk/cXtYdZ
#vgextend /dev/vg00 /dev/dsk/cXtYdZ
#efi_cp -d /dev/rdsk/cXtYdZs1 /tmp/auto /EFI/HPUX/AUT0
#for i in /dev/vg00/lvol*
>do
>lvextend -m 1 $i /dev/dsk/cXtYdZs2
>done

after mirroring is over
#lvlnboot -v
#lvlnboot -R
#lvlnboot -v
#vi /stand/bootconf
to make sure that the emtries are in there for "l /dev/dsk/cXtYdZs2"

setboot
to check and set HW path of cXtYdZ as the Altrnate / HAA path.
regards
sujit

[sujit kumar singh]

hi


What i thinkk the idisk step in the earlier post can be avoided as the Prtns will be ther only on the disk.

just put in the disk
do an ioscan
dothe remirroring

#for i in /dev/vg00/lvol*
>do
>nohup lvextend -m 1 $i /dev/dsk/cXtYdZs2
>done

regards
sujit

[Trng]

Dear Sujit/All,

1-i am handling server remotely..earlier both hdd were in mirrord state..as part of software installtion i removed one mirror harddisk(not physically unplugged) using lvreduce -m 0 and then vgexport that disk..is it correct ,using this incase of any disater can we boot it from second disk ??

2-what is the best way to safely keep one OS hardisk(pls excuse unplugg one mirrord hdd online and drd options )

3-consider my real problem,how to remirror it ?simply vgextend and lvextend -m 1 all lvols will work ???


rgds
trng

[sujit kumar singh]

Hi


3)Yes, the vgextend and the lvextend to extend the mirrors shall work.

2)You can unplug a HDD at the time of upgrade or can use DRD ( DRD is a more grammatical and Logical Approach). In case you might need to boot from the unplugged disk just use the EFI boot from the altrnate path.

3)Or the way that you have tried also helps you achieve the same thing. But in this case say if you need to reboot the Server using this HDD that you had vgreduced you will need first to boot using that disk in the LVM maint mode and export and import the VG using this HDD.

regards
sujit

[Trng]

Dear Sujith,

Let us think a new case,i have a root disk which is mirrord.now i have to install some critical software/patches..i dont want to go for restoration etc incase of crash.so i want to split one mirror hardisk remotely(pls excuse ignite ,drd,unplugg options)


rgds
trng

[sujit kumar singh]

hi

In your case also one thing can be tried.

1) #vgcfgrestore -l -f /etc/lvmconf/vg00.conf.old

see if this defintion list has got the earlier disk that is /dev/dsk/c1t1d1s2


If you can find the disk in the earlier config that is /etc/lvmconf/vg00.conf.old with the help of the above command then the vgcfgrestore shall solve th prob of remirroring.

If (1) above yields /dev/dsk/c1t1d1s2 is there in the config , do
#vgcfgrestore -f /etc/lvmcong/vg00.conf.old /dev/rdsk/c1t1d1s2


#vgsync

and if reqd lvsync

#for i in /dev/vg00/lvol*
>do
>nohup lvsync $i
>done

regards'
sujit

[sujit kumar singh]

Hi

In that case what you need is to do

1)lvsplit
2)perform the upgrade
3)lvmerge the LVs.


1)
#for i in /dev/vg00/lvol*
>do
>nohup lvsplit -s $i
>done

2) Perform the application upgrade

3)merge the LVs one by one

#lvmerge /dev/vg00/lvol1backup /dev/vg00/lvol1

and so on for all the LVs.
this merges the LV /dev/vg00/lvol1backup with the /dev/vg00/lvol1 considering the /dev/vg00/lvol1 as the current data source.

please refer to the following:

Refer to the appendix of When_Good_Disks_Go_bad

http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad_WP.pdf

and the manpages of the command lvsplit(1M) and lvmerge(1M).

http://docs.hp.com/en/B2355-60130/lvsplit.1M.html

http://docs.hp.com/en/B2355-60130/lvmerge.1M.html


regards
sujit

[Trng]

Dear Sujith,

1-if i spliT using lvsplit ,is it possible to boot from that disk incase of primary disk OS fail?

2-IF i split using lvreduce -m 0 and vgreduce ,second disk will be bootable ,incase of primary disk OS crash?

[sujit kumar singh]

Hi

lvsplit case

you will need to take the system in the LVM maintenance mode booting from that disk and export and reimport the rootvg using that disk, and do an lvlnboot for the root,boot,swap and dump LVs and reboot.
then reboot the system in the quorum override mode.

lvreduce and vgreduce case:

in case of this as the other disk has gone out of the LVM vg00 config, still boot using that disk in the LVM maint mode and export and reimport the VGH, set the boot,swap,root and dump using the lvlnboot and reboot the system in the Quorum Override mode.
regards
sujit