Howto create Mirrored volume

[Pocius Arturas]

How to create mirored lvolumes from scratch on SC10? (Root, boot and othr.)

Thanks.

[Joseph Chakkery]

Pvcreate ???B (-f for force if file system exists) /dev/rdsk/c?t?d?Vgextend /dev/vg00 /dev/dsk/c?t?d?Mkboot /dev/rdsk/c ?t ?d ?
Mkboot ???a ?? hpux;0)/stand/vmunix??? /dev/rdsk/c?t?d?
Lvextend ???m 1 /dev/vg00/lvol1 /dev/dsk/c?t?d?Same for all other volume to be mirrorLvlnboot ???R

Hope this will help u.

Regards
Joe.

[Sarah Mokwana · Accepted solution]

"N.B. IN THE EXAMPLE I'LL USE /dev/dsk/c0t5d0"
# pvcreate -B /dev/rdsk/c0t5d0
Add the physical volume to the existing root volume group with vgextend:
# vgextend /dev/vg00 /dev/dsk/c0t5d0
Use mkboot to place boot utilities in the boot area:

# mkboot -l /dev/rdsk/c0t5d0
Use mkboot to add an AUTO file in boot LIF area:

# mkboot -a "hpux" /dev/rdsk/c0t5d0

Or, use the -lq option to allow the system to boot in the event that one of the disks is unavailable, resulting in a loss of quorum.

# mkboot -a "hpux -lq" /dev/rdsk/c0t5d0

NOTE: Use the -lq option when the root volume group contains only 2 disks. If more than 2 disks are in the root volume group, the -lq option is not needed
as quorum will be maintained even if 1 disk fails.

Check the contents of the AUTO file with

# lifcp /dev/rdsk/c0t5d0:AUTO -

Alternatively, one could set the alternate boot path variable according to e.g.

# setboot -a 8/0/19/0.5.0

The hardware address of the disk that will become the mirror disk can be determined with 'ioscan -fnC' disk. To check use setboot without any arguments.

Use pvdisplay -v to the order of the logical volumes on the primary disk.

# pvdisplay -v /dev/dsk/c0t6d0

NOTE: In the following, the standard sequence lvol1, lvol2, lvol3, and so forth, is assumed.

Mirror the boot logical volume, primary swap logical volume, root logical volume and other logical volumes as needed, to the mirror disk in the correct sequence

# lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/c0t5d0
# lvextend -m 1 /dev/vg00/lvol2 /dev/dsk/c0t5d0
# lvextend -m 1 /dev/vg00/lvol3 /dev/dsk/c0t5d0
# lvextend -m 1 (additional LV)

Use pvdisplay -v to the order of the logical volumes on the mirror disk to insure they are in the correct order.

# pvdisplay -v /dev/dsk/c0t5d0

Update all physical volumes in the volume group so that the logical volume become the root, boot, primary swap, or a dump volume when the system is next booted:

For HP-UX 10.20 (not updated to) and 11.X only:

# 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

Check with

# lvlnboot -v

[Sanjay_6]

Hi,

I think you are talking about a disk array. Do you want to mirror lv's which belong to an array. The array already has redundancy in it.

Hope this helps.

Regds

[Sandip Ghosh]

Hi,

I think you don't need to create the mirrored logical volume separately. Because if you look at the SC10 documentation came with that, you can find the settings to configure this as RATD 1 (which is equivalent to mirroring). And ofcourse, after configuring it as RAID 1 you can find only 5 volumes because other 5 will be mirrored one. And hardware mirror is always faster than Software mirror. So you should configure it as a RAID 1 enclosure.

Sandip

[Pocius Arturas]

I want to use this mirrored disks feature to make cold backup of Oracle DB without stoping instances (taking one disk off mirror). Is it normal to use scripting and crond for this jobs?

Thanks

[Sanjay_6]

hi,

We use mirroring for redundancy. To take oracle backup, we normally put the datbase in hot backup mode, take the backup and then take the database out of hotbackup mode. The database performance is a little slow, but we don't have to shutdown the database in this case. you may explore the snapshot option if you have online JFS on the system.

The hotbackup we run for oracle is configured in cron for some servers and we use omniback and veritas netbackup for some. Omniback and veritas netbackup have their own intergration tools for oracle.

Hope this helps.

Regds

[fg_1]

Arturas

Here is a procedure that I have, it's for mirroring root, but you can strip out the pieces that deal with the root part.

[mvpel]

Sarah, is it necessary to update /stand/bootconf file to include the additional disk as well?

I'm not quite clear on how that file is used.