topic Re: MIRROR PROBLEM in Operating System - HP-UX

MIRROR PROBLEM

dhanish — Wed, 23 Jan 2002 04:36:17 GMT

I have mirrored by OS disk and it has 1 mirror copy.But When i give lvdisplay -v /dev/vg00/lvol1(the lgical volume of where os is ),I see stale as status.

lvdispay -v /dev/vg00/lvol1 ---> o/p follows

LE PV1 PE1 Status 1 PV2 PE2 Status 2
0000 /dev/dsk/c2t5d0 0000 stale /dev/dsk/c2t6d0 0000 current
0001 /dev/dsk/c2t5d0 0001 stale /dev/dsk/c2t6d0 0001 current
0002 /dev/dsk/c2t5d0 0002 current /dev/dsk/c2t6d0 0002 current
0003 /dev/dsk/c2t5d0 0003 current /dev/dsk/c2t6d0 0003 current
0004 /dev/dsk/c2t5d0 0004 current /dev/dsk/c2t6d0 0004 current
0005 /dev/dsk/c2t5d0 0005 current /dev/dsk/c2t6d0 0005 current
0006 /dev/dsk/c2t5d0 0006 current /dev/dsk/c2t6d0 0006 current
0007 /dev/dsk/c2t5d0 0007 current /dev/dsk/c2t6d0 0007 current
0008 /dev/dsk/c2t5d0 0008 current /dev/dsk/c2t6d0 0008 current
0009 /dev/dsk/c2t5d0 0009 current /dev/dsk/c2t6d0 0009 current
0010 /dev/dsk/c2t5d0 0010 current /dev/dsk/c2t6d0 0010 current
0011 /dev/dsk/c2t5d0 0011 current /dev/dsk/c2t6d0 0011 current
0012 /dev/dsk/c2t5d0 0012 current /dev/dsk/c2t6d0 0012 current
0013 /dev/dsk/c2t5d0 0013 current /dev/dsk/c2t6d0 0013 current
0014 /dev/dsk/c2t5d0 0014 current /dev/dsk/c2t6d0 0014 current
0015 /dev/dsk/c2t5d0 0015 current /dev/dsk/c2t6d0 0015 current
0016 /dev/dsk/c2t5d0 0016 current /dev/dsk/c2t6d0 0016 current
0017 /dev/dsk/c2t5d0 0017 current /dev/dsk/c2t6d0 0017 current
0018 /dev/dsk/c2t5d0 0018 current /dev/dsk/c2t6d0 0018 current
0019 /dev/dsk/c2t5d0 0019 current /dev/dsk/c2t6d0 0019 current
0020 /dev/dsk/c2t5d0 0020 current /dev/dsk/c2t6d0 0020 current

Now for the LE 0000 AND 0001 the status is stale for the original disk.What does it mean , is it giving some warning to me.

thnks

Re: MIRROR PROBLEM

Patrick Wallek — Wed, 23 Jan 2002 04:41:13 GMT

What happens if you do an:

# lvsync /dev/vg00/lvol1

Now do your lvdisplay command again. Does it still show as stale? If not, I think you're fine. If it doesn't sync up and still shows stale, then I would go ahead and replace the disk as it is probably going bad.

Re: MIRROR PROBLEM

Sanjay_6 — Wed, 23 Jan 2002 04:42:33 GMT

Hi Nitin,

Looks like there may be some problem with the root disk. Do a "vgdisplay -v /dev/vg00" and check the status of the different LV's over there. They should show the status as syncd/available. If the same is shown as syncd/stale, it means there is a problem with one of the disk. Do a pvdisplay on the disks "pvdisplay -v /dev/dsk/cxtydo"

Do this for both the disks in the root vg and if it shows stale on any extend, do a "vgsync /dev/vg00". If that still shows a problem, you need a replacement disk.

Hope this helps.

Regds

Re: MIRROR PROBLEM

dhanish — Wed, 23 Jan 2002 04:47:37 GMT

[root@sanga]:/ 2340 # lvsync /dev/vg00/lvol1
lvsync: Couldn't re-synchronize stale partitions of the logical volume:
I/O error
lvsync: Couldn't resynchronize logical volume "/dev/vg00/lvol1.

So you mean to say that my original disk (OS disk) has gone bad and system is running with the mirror disk at present ????is it right ??.

I do not have the replacement disk at present ( do i have to break the mirror ..if yes how?).So can i boot the system (changing the primary path of the boot ) to the mirrored disk and once i get the new disk and at that time my system will be running with the mirrored disk so what i ahve to do to recreate the mirror.

Re: MIRROR PROBLEM

Sanjay_6 — Wed, 23 Jan 2002 04:52:55 GMT

Hi Nitin,

You don't have to break the mirror. Get a replacement disk and then you can remove the defective disk, put the new disk in, boot using your mirror disk and then do a vgcfgrestore to restore the boot disk conf to the new disk. Do a mkboot to make the new disk bootable, do a vgsync to sync and mirror the lv's and then reboot using your primary root disk. I was required to replace the root disk a few days back on one of my system.

Here is a link from itrc to give you a little hand,

http://us-support3.external.hp.com/cki/bin/doc.pl/sid=fdb3a9de19e1ec33ae/screen=ckiDisplayDocument?docId=200000057581212

Hope this helps.

Regds

Re: MIRROR PROBLEM

Michael Tully — Wed, 23 Jan 2002 04:52:57 GMT

Hi,

It looks like one of your disks is on
the way out... Get it replaced. Some
servers don't need to shutdwon the server,
as the disks are hot-swappable, which means
that replacing the disk, the two disks will
re-sync. That is one reason why MirrorDisk/UX
is so good!

-Michael

Re: MIRROR PROBLEM

Patrick Wallek — Wed, 23 Jan 2002 05:00:18 GMT

It appears that your disk is going bad, yes!

What type of system is this? Are the disks that the OS is hot swappable?

If so, then you just replace the disk, do a vgcfgrestore to the disks, go through the pvcreate commands to make it bootable, and then do a vgsync to resynchronize the mirror. You don't have to break the mirror and you don't have to reboot if your disks are hot swappable.

Here are a couple of threads that discuss replacing root disks:

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xd5cfe7726eccd5118ff10090279cd0f9,00.html

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xa601670142b2d5118ff10090279cd0f9,00.html

You should really have a look at the ITRC document that they mention in both threads as well .

Re: MIRROR PROBLEM

dhanish — Wed, 23 Jan 2002 05:12:56 GMT

My system model is 9000/889/K460.So are the internal os disks are hot swappable.
so i have decided to the follwowing steps.

1)Remove the primary disk online if its a hot swappable.
2)BOOT THE SYSTEM WITH THE ALTERNATE DISK
3)when i get the new disk.Do i ahve to boot the system in hpux -lm (mode )IF YES then what it will do?? As i read this in one of the document.

3)then i will do pvcreate on the newdisk
4)then vgrestore -n vg00 /dev/rdsk/c0t1d0(newdisk)

its correct???

Re: MIRROR PROBLEM

Steven Sim Kok Leong — Wed, 23 Jan 2002 05:16:17 GMT

Hi,

It is vgcfgrestore, not vgrestore. In addition, be sure to set the SCSI ID of your new harddisk the same as the faulty one.

Hope this helps. Regards.

Steven Sim Kok Leong

Re: MIRROR PROBLEM

dhanish — Wed, 23 Jan 2002 05:21:17 GMT

Yes it was a typo.But the disks in this model are hot swappable???

thnks

Re: MIRROR PROBLEM

Patrick Wallek — Wed, 23 Jan 2002 05:21:53 GMT

It's a K460 with the OS on the internal drives? Right?

If that is the case the internals are NOT hot swappable.

Here are the steps I would take:

1) Call HP and schedule them to bring out a replacement disk (do NOT reboot the system until then. It should run fine with the mirror. That is the whole point of mirroring after all!)

2) Shutdown the machine
3) Replace the disk
4) Reboot the machine from the alternate drive. Interact with IPL and use 'hpux -lq' (I think -lq is the option to boot without a quorum)
5) pvcreate the disk
6) vgcfgrestore to the disk
7) do your mkboot commands
8) vgsync vg00 to resync the mirrors
9) do a 'lvlnboot -v' to make sure all info is correct
10) reboot and let the machine come up on the primary to make sure all is OK.

Good luck.

Re: MIRROR PROBLEM

Sanjay_6 — Wed, 23 Jan 2002 05:26:10 GMT

Hi Nitin,

If it is a K460 and the primary root disk is internal (within the system cabinet) it is not hot swappable. You have to shutdown the system and remove it. What you have to do is shutdown the system, replace the disk, boot the system in single user mode using the alt disk, you can use the lvm maintainance mode or the boot mode without quorum. Use the without quorum option, i.e don't boot into lvm maintainance mode. Do this,

bo alt_disk_path

select y to interact with ipl,
at the ipl prompt type,

hpux -lq (;0)/stand/vmunix

The system will boot, do a vgcfgrestore on the primary disk, and then do the rest of the stuff outlined in the link posted earlier. It should go smoothly.

Hope this helps.

Regds