topic Re: Mirror question in Operating System - HP-UX

Mirror question

castro_2 — Tue, 18 Feb 2003 13:15:00 GMT

I have a vg00 with 2 disk, Can I mirror whith another 2 disks?
And my swap has 2 logical volumen /dev/vg00/lvol2 /dev/vg00/lvol9
Thanks

Re: Mirror question

Pete Randall — Tue, 18 Feb 2003 13:16:50 GMT

Assuming you have the MirrorDisk/UX product installed, yes. Add the two disks to vg00, then mirror each individual lvol with lvextend -m 1.

Pete

Re: Mirror question

Jerome Baron — Tue, 18 Feb 2003 13:18:01 GMT

Hi,

To mirror your vg00 :
- vgextend /dev/vg00 /dev/dsk/cxtydz
(cxtydz is the disk device file)
- lvextent -m 1 /dev/vg00/lvolI
For all lvol in the vg.

Regards,
Jerome

Re: Mirror question

James R. Ferguson — Tue, 18 Feb 2003 13:20:05 GMT

Hi:

MirrorDisk/UX implements mirroring at the logical volume level. For vg00, make you mirror, at least, lvol1, lvol2 and lvol3 first, and in that order.

Regards!

...JRF...

Re: Mirror question

Armin Feller — Tue, 18 Feb 2003 13:37:20 GMT

Mirror the root disk (vg00):

swlist -l fileset | grep -i mirror

# pvcreate -B /dev/rdsk/c...
# pvcreate -B /dev/rdsk/c...

# vgextend vg00 /dev/dsk/c... /dev/dsk/c...

# mkboot -l /dev/rdsk/c...
# mkboot -a "hpux -lq" /dev/rdsk/...
# lifcp /dev/rdsk/c...:AUTO -
# setboot -a 8/0/19/0.5.0

# lvextend -m 1 /dev/vg00/lvol1
# lvextend -m 1 /dev/vg00/lvol2
# lvextend -m 1 /dev/vg00/lvol3
...
in this order

# lvlnboot -r /dev/vg00/lvol3 /dev/vg00
# lvlnboot -b /dev/vg00/lvol1 /dev/vg00
# lvlnboot -s /dev/vg00/lvol2 /dev/vg00
# lvlnboot -d /dev/vg00/lvol2 /dev/vg00
# lvlnboot -v

Regards ...
Armin

Re: Mirror question

Ravi_8 — Tue, 18 Feb 2003 13:37:45 GMT

Hi,

You can do mirroring provided you have MirrorDisk product installed,

perform mirroring only for useful filesystem ( don't consider swap, tmp)
#lvextend -m 1 /dev/vg00/lvolx /dev/dsk/cxtxdx

Re: Mirror question

James R. Ferguson — Tue, 18 Feb 2003 13:46:11 GMT

Hi (again) Castro:

I should clarify my post, so not to be misunderstood. For a viable mirror of vg00 you need to maks sure you mirror lvol1, lvol2 and lvol3 in that order. You *should*, mirror all logcial volumes of vg00, however. This makes recovery of a failed disk the easiest.

In additon, make sure to set a low-quorum on the mirrowed disk as well as the original:

# mkboot ???a "hpux ???lq" /dev/rdsk/cXtYdZ

...and set the new mirrored disk as an alternate boot disk:

# setboot ???a [alternate_path]

Regards!

...JRF...

Re: Mirror question

castro_2 — Tue, 18 Feb 2003 13:55:24 GMT

Yes I have MirrorDisk.
ANd with the swap?

Re: Mirror question

T. M. Louah — Tue, 18 Feb 2003 14:01:46 GMT

PLS note that Mirroring is only tested at boot time, make sure it works !!

# shutdown -ry 0

The system will shut down and reboot. As the system starts to come back up, look for the message (system's output may vary):

TO INTERRUPT THE BOOT SEQUENCE, PRESS ...

Interrupt the boot sequence. This will display the Boot Admin display. At the boot_admin> prompt type:

bo Mirror_disk_hardware_address or
bo alt

if the alternate boot device has been configured. The system will prompt to interact with IPL, answer 'no', and the system will boot from the mirror root disk.

Cheers,
PAP! (a.k.a. Pliz assign Points )

Re: Mirror question

Trond Haugen — Tue, 18 Feb 2003 14:03:54 GMT

Having your question answered already I would just like to add that you can mirror to ONE other disk.
The roule is that you must mirror to another disk. If you r vg00 is made up of say two 9Gb disk, you could mirror to one 18Gb disk.

Regards,
Trond

Re: Mirror question

Pete Randall — Tue, 18 Feb 2003 14:07:17 GMT

Yes, mirror the swap as well.

Pete

Re: Mirror question

castro_2 — Tue, 18 Feb 2003 14:43:48 GMT

Last question.
I have several logical volumes in 2 disk

LV Name /dev/vg00/lvol7
VG Name /dev/vg00
--- Distribution of logical volume ---
PV Name LE on PV PE on PV
/dev/dsk/c9t5d0 160 160
/dev/dsk/c9t9d0 140 140

When I do the lvextend -m 1
what disk is?
Thnaks

Re: Mirror question

James R. Ferguson — Tue, 18 Feb 2003 14:52:19 GMT

Hi Castro:

When you do the 'lvextend -m...' *all* extents of the logical volume on *all* physical volumes on which it resides are extended. Remember that mirroring is at the *logical volume* level. You can limit the mirror to a particular physical volume(s) by specifying the pv_path(es). Otherwise, all physical volumes are candidates for the mirror extents, within the constraints of the 'strict' allocation policy (which by default, prevents allocating mirror extents on the same physical volume as corresponding extents already exist).

See the man pages for 'lvcreate' and 'lvextend' for more information.

Regards!

...JRF...