Check disk mirror on the HPUX server

[ASH_27]

Hi

Disk mirroring is enabled on our HP-UX server running 11.11 U 9000/785. How do I test mirroring ? Basically to check both the disk has same data and other disk can boot incase of primary fails.

Thanks

[Bill Thorsteinson]

Do a vgdisplay -v on the volume which contains
the mirrored disks. Mirrored logical volumes should show 2 used disks.
Do a lvdisplay -f on the logicial volume. It will list the logical blocks of the volume,
physicial mapping on each disk, and
syncronization status.

[Sanjay_6]

Hi,

the only way you can verify that the mirroring is going to work or is okay is by rebooting the server with your mirror disk and make sure the primary is out of the slot.

Hope this helps.

regds

[Geoff Wild]

Here's a handy script called chkdisks...

Output like:

# chkdisks
Logical Volume Filesystem Mirrored?
-------------- ---------- ---------
/dev/vg00/lvol1 /stand yes
/dev/vg00/lvol2 yes
/dev/vg00/lvol3 / yes
/dev/vg00/lvol4 /tmp yes
/dev/vg00/lvol5 /home yes
/dev/vg00/lvol6 /opt yes
/dev/vg00/lvol7 /usr yes
/dev/vg00/lvol8 /var yes
/dev/vg00/lvol9 /app yes
/dev/vg00/lvol10 /ops yes
/dev/vg00/lvol11 /data yes
/dev/vg00/lvol12 /opt/cctool yes
/dev/vg00/lvol13 /var/opt/perf/datafiles yes
/dev/vg00/lvol14 /usr/openv yes
/dev/vg00/lvpub yes
/dev/vg01/lvol2 /var/adm/crash yes
/dev/vg01/swap yes


lvlnboot -v to check if disk is bootable:


# lvlnboot -v
Boot Definitions for Volume Group /dev/vg00:
Physical Volumes belonging in Root Volume Group:
/dev/dsk/c20t5d0 (0/0/0/3/0.5.0) -- Boot Disk
/dev/dsk/c0t6d0 (1/0/0/3/0.6.0) -- Boot Disk
Boot: lvol1 on: /dev/dsk/c20t5d0
/dev/dsk/c0t6d0
Root: lvol3 on: /dev/dsk/c20t5d0
/dev/dsk/c0t6d0
Swap: lvol2 on: /dev/dsk/c20t5d0
/dev/dsk/c0t6d0
Dump: lvol2 on: /dev/dsk/c20t5d0, 0


Rgds...Geoff

[Victor BERRIDGE]

Hi,
About booting:
be sure you put both disks in the boot search path:
$ setboot
Primary bootpath : 0/0/1/1.2.0
Alternate bootpath : 0/0/2/0.2.0

Autoboot is ON (enabled)
Autosearch is OFF (disabled)


Do a man of setboot...


All the best
Victor

[DCE]

one additional command that will help

lvlnboot -v

This will tell ypu if the boot partition has been installed on both disks.

[ASH_27]

Thanks for all reply.
Can you let me know
--- Physical volumes ---
PV Name /dev/dsk/c3t6d0
PV Status available
Total PE 4340
Free PE 674
Autoswitch On

PV Name /dev/dsk/c3t5d0
PV Status available
Total PE 4340
Free PE 674
Autoswitch On

What does it mean?

[Geoff Wild]

That is 2 physical volumes of a volume group - PE = Physical Extents...

Multiply the PE by PE Size (Mbytes) to get space in MB.

IE - if youe PE Size is 8, then your disk are 34720 MB in size with 5392 MB free.

Rgds...Geoff

[Pete Randall]

The fields displayed are the output of pvdisplay and, thusly, are explained (quite well) in the man page for pvdisplay. I started out to quote them in here, but it was taking too long to reformat - you can look them up.


Pete

[Pete Randall]

Sorry - disregard that last. I was replying to another question, got the "Internal System Error" message and when I went back to post again, I ended up in this thread - weird!.


Pete

[ASH_27]

Geoff Thanks for reply.

So in this scenario I have 5GB of free space, to make use of it I need to mount it as LV correct as another partition ?

Rgds...ASH

[Pete Randall]

I'll take that back. Right thread. I was responding to the author's last question.

I hope quitting time gets here soon!


Pete

[James R. Ferguson · Accepted solution]

Hi:

To use the additional physical disk extents that yuo have free, you can either 'lvextend' an existing logical volume, thus adding them to it or 'lvcreate' a new logical volume.

In either case, the logical volume is only a container for a file system. Thus, if you 'lvextend' an existing logical volume, you will want to follow that with an enlargement of the file system contained therein. Assuming a JFS (VxFS) filesystem, you would use 'fsadm' to grow the filesystem.

If you are creating a new logical volume, then you follow that with the creation of a new filesystem within it, with 'newfs'.

An excellent manual section for you to read is chapter-6 of the "Magaging Systems and Workgroups" guide:

http://docs.hp.com/en/B2355-90912/B2355-90912.pdf

Regards!

...JRF...

[Geoff Wild]

That is correct, and James provided you with a link to a good doc with steps to add a lvol.

Rgds...Geoff

[Jason S. Bailey]

If you want to change the boot device and make sure the system will boot off the mirrored disk... (note: this assumes you mirrored the disk properly and have the lif area all set up with mkboot and whatnot):

1. vi /stand/bootconf - make sure both discs are listed.

2. ioscan -fnC disk - look at the hardware path for each disk, then run. setboot -p 0/0/0/0.0.0 (substitute hw path for primary boot drive) and setboot -a 0/0/0/0.0.0 (hw path for secondary boot drive).

3. lvlnboot -R. this updates the boot area on the drives.

4. reboot & interrupt the boot process when prompted. at the prompt, type boot alt then say no to interact and it should boot off the second disk.

5. once you're up and running, type this:

echo boot_string/S | adb /stand/vmunix /dev/kmem

this should return the hardware path of the system you're booted off of. make sure it says the hw path for your second device. to go back, shutdown -ry 0, interrupt, boot pri and it should come back up on the original disk.