topic Re: L2000 internal disk trick in Operating System - HP-UX

L2000 internal disk trick

Marc Ahrendt — Thu, 20 Jun 2002 16:38:39 GMT

want to quickly copy a L2000 configuration from one machine (call it frog) to another machine (call it toad). i know about Ignite, but can i do the following instead.

frog has 4 drives and using LVM to mirror disk A0 to A1 and B0 to B1. toad is a new system with all its 4 drives new/unused. what would be the procedure to break the 2 mirrors on frog and use A1 and B1 from frog on toad? then, of course, rebuild both mirros on frog and toad (then change netconf on toad before putting it on the network)

is it possible to do without taking frog offline?

Re: L2000 internal disk trick

Paula J Frazer-Campbell — Thu, 20 Jun 2002 17:02:43 GMT

Marc

The hardware paths will have to match for this to work.

Paula

Re: L2000 internal disk trick

Arockia Jegan — Thu, 20 Jun 2002 17:23:18 GMT

I guess both systems are identical. By using the combination of lvreduce, vgreduce, vgextend and lvextend command you should be able to do that without taking frog offline.

Re: L2000 internal disk trick

S.K. Chan — Thu, 20 Jun 2002 17:58:51 GMT

To break the mirror .. (eg: a 2 disks mirrored vg00 and c2t2d0 is the mirrored disk)
# lvreduce -m 0 /dev/vg00/lvol2 /dev/dsk/c2t2d0
==> Repeat for all LVs.
# lvlnboot -v
==> Check.
# vgreduce vg00 /dev/dsk/c2t2d0
# lvlnboot -v
==> Check again.
If it's a data disk you would just do the "lvreduce" and "vgreduce". That's it as far as breaking the mirror (and you can do this while the system is running).
I've done a lot of vgexport/vgimport , moving data disks around but not this scenario that you're trying to do I can't really confirm if it'll work since I have not try it before. However in theory (after the above sre done), you should be able to physically disconnect drive A1 and plug it onto toad (keep all hrw path the same), boot up toad using A1 in LVM maintenance mode ..
ISL> hpux -lm
then activate it ..
# vgchange -a y /dev/vg00
Now mount the appropriate LV onto the FS and make your changes (eg : the netconf file that you've mentioned earlier).
Having said all that I would prefer going the Ignite route just to be cleaner.

Re: L2000 internal disk trick

MANOJ SRIVASTAVA — Thu, 20 Jun 2002 18:08:32 GMT

Marc

It is possible thje way you are suggesting , but I would defiantley witch off the system once i remove the disk. The better and safer way woulb be to do ignite the other server.

Manoj Srivastava

Re: L2000 internal disk trick

Martin Johnson — Thu, 20 Jun 2002 18:15:32 GMT

Make sure the systems are not on your network. Or the very least toad is not on the network. You will need to reconfigure toad's network parameters before you bring it online.

Ignite would take care of this with an interactive boot.

HTH
Marty

Re: L2000 internal disk trick

Sanjay_6 — Thu, 20 Jun 2002 18:21:08 GMT

Hi Marc,

You can try this procedure to create a copy of the root disk without using mirror/ux or ignite. You can then move the copy to the other server and try to boot that system using the disk. You can try this without shuttting down the system provided the disks are hot-swappable. Try this link,

http://support1.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000058668933

Hope this helps.

Regds

Re: L2000 internal disk trick

PIYUSH D. PATEL — Thu, 20 Jun 2002 18:23:23 GMT

Hi,

I would prefer doing this thro Ignite since you will have to take lot of precuations in the method which you are trying to do. You may end messing up both the systems since one command here and there.......

Once you bring up your Toad server, you have to keep the Frog switched off since the IP address of both the servers will be the same. And you need to change the IP of the Toad and then boot up the Frog.

Piyush

Re: L2000 internal disk trick

Tim D Fulford — Thu, 20 Jun 2002 20:26:58 GMT

just one thing....

If you miror split & remirror, the VGID's for vg00 on the frog & toad will be the same.!!!! If the machines are to be put in ServiceGuard it will confuse the hell out of it, and it will "deduce" (incorrectly) that the root disks are indeed the same (it reads the VGID from each computer & compares notes). At this point it may barf or continue. It may well work, with the above warning.

What is wrong with IgniteUX, it is pritty quick & by the time you've fiddled 'round with disks etc you will probably not save much time.

But then again if you do not experiment you might not learn.... If you do do it, post the results please

Regards

Tim

Re: L2000 internal disk trick

Marc Ahrendt — Thu, 20 Jun 2002 23:13:17 GMT

will assign points after i try this over the weekend, and will post my results here too. yes i know about Ignite and have an Ignite server and a Legato server ...just want to experiment and have another option for recovering and/or building a copy of a L200 that has the identical hardware setup as another. we do not have Service Guard here.

all 4 disks are in vg00 and have no other VGs. so my game plan so far is:
1) lvreduce all LVs
2) vgreduce disks A1 and B1
3) pull out A1 and B1 ...frog should still be online and users unaware
4) place these 2 disks in the exact same slots on toad and take the 2 removed disk from toad and place in frog
5) run ioscan then do the LVM stuff to get frog back to being mirrored
pvcreate, vgextend, lvextend, lvlnboot
6) disconnect toad from the network and boot system
no need to do "hpux -lm" ...i think
7) repeat step 5 for toad
8) edit netconf file and reboot
will plug into the network after verify that toad boots up OK

anything look incorrect?

Re: L2000 internal disk trick

Tim D Fulford — Fri, 21 Jun 2002 13:06:40 GMT

looks good to me...you brave guy...

Tim

Re: L2000 internal disk trick

Marc Ahrendt — Fri, 05 Jul 2002 13:34:56 GMT

well not that brave ...i tried it and at this point am stuck

1) was able to steps 1-> 5 OK
so frog, my online machine is OK
2) stuck rebuilding vg00 on toad
cannot get vg00 to activate!

i put A1 and B1 from frog into the exact same slots on toad. A0 and B0 on toad are empty/new drives. when i boot via "hpux -lm" all is OK until i try to do a "vgchange -a y -q n vg00".
it seems that doing the "vgreduce" on these disks when they were on frog has messed up some of the LVM metadata on these disks. any tricks from here? want to ask before trying to do a vgimport or vfcfgrestore ... i do not have a vgexport file but do have a /etc/lvmconf/vg00.conf

any help would be great, else i have to conclude that this procedure is not valid ...unless there are steps i could of done better on frog to prepare these A1 and B1 disks for use on toad.

Re: L2000 internal disk trick

Marc Ahrendt — Fri, 05 Jul 2002 13:38:17 GMT

sorry ...for got to state that the problem is that vg00 will not activate when running the vgchange command

Re: L2000 internal disk trick

Tim D Fulford — Fri, 05 Jul 2002 19:44:44 GMT

Haven't been following thread for a while...

if booting from PDC
ISL> hpux -lq

If activating it
# vgchange -q n -a y vg00

Both these activate in "lost quorum" mode, Hope this helps

Tim

Re: L2000 internal disk trick

Marc Ahrendt — Mon, 08 Jul 2002 03:40:34 GMT

sorry for not clarifying...

i am aware of quorum and have done all the right stuff to ignore quorum and it still will not activate.

....just wondering if the lvreduce and/or the vgreduce on these drives when they were on frog has messed up some of the LVM metadata on them.

so it looks like my trick is not one at all. one last thing i was thinking of doing was recreate vg00 on toad while in "hpux -lm" mode, and using the same LE to PE mappings when building the LVs. maybe by recreating the LVM metdata from scratch i can get by!?!