Mirror-UX

[Brian Abdallah_2]

I am thinking of purchasing a ds2100 disk system along with 2 x 73gb disks. I will create vg01 and vg02 and associated lvols. I will use the second disk to mirror the lvols. If I want to add more storage later, ie. create another volume group. will I need to purchase two disks in order to mirror the lvols. Please advise.

[Pete Randall]

Mirroring is done at the logical volume level, so you could have new, un-mirrored lvols but I would think you would want to purchase two disks to be consistent with your mirroring policy and avoid confusion.


Pete

[Pete Randall]

Mirroring is done at the logical volume level, so you could have new, un-mirrored lvols but I would think you would want to purchase two disks to be consistent with your mirroring policy and avoid confusion.

One other thing: with only two disks, one of which is a mirror for the first, you can only have one volume group because a physical disk can only belong to one VG.


Pete

[Stuart Abramson_2]

Right. 2 x disks (mirrored) = 1 VG.

To get 2 VGs, mirrored at LV level on different disks, you would need 4 x disks.

[G. Vrijhoeven]

Hi Brian,

A lvol must be mirrored over multiple (2) disks in the same volume group and a disk can only belong to one volume group. So you will have to adjuist your plan and make more lvols in one volumegroup and mirror them.

Gideon

[Steven E. Protter]

As a reference I'm providing this cookbook which tells how to mirror a boot volume.

pvcreate -B /dev/rdsk/c1t0d0 #use real disk

mkboot -l /dev/rdsk/c1t0d0
mkboot -a "hpux -lq (;0)/stand/vmunix" /dev/rdsk/c1t0d0 # use real disk


# mkboot -b /usr/sbin/diag/lif/updatediaglif -p ISL -p AUTO -p HPUX -p PAD -p LABEL /dev/rdsk/c?t?d?

If you are running 64-bit OS:

# mkboot -b /usr/sbin/diag/lif/updatediaglif2 -p ISL -p AUTO -p HPUX -p PAD -p LABEL /dev/rdsk/c?t?d?


vgextend /dev/vg00 /dev/dsk/c1t0d0 # same thing
lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/c1t0d0

# real disk. repeat for other lvols

lvlnboot -r /dev/vg00/lvol3 # root fs /
lvlnboot -s /dev/vg00/lvol2 #swap
lvlnboot -d /dev/vg00/lvol2 #swap/dump
lvlnboot -b /dev/vg00/lvol1
lvlnboot -R
lvlnboot -v
setboot
setboot -a 52.1.0 # second disk


Its is safe to skip most of these steps, the ones tha have the word boot mostly if mirroring non-boot logical volumes.

SEP

[Brian Abdallah_2]

So, if I want to have two volume groups,
vg01 and vg02 mirrored, then I will require 2 disks for each volume group?
But, if I don't mirror the vg's then I can get away with two disks? vg01 and vg02?

[Marco Santerre]

Exactly,

If you mirror your VGs that means you'll need 2 disks inside vg01 and another 2 disks inside vg02.

If you don't mirror. You can have 1 disk inside vg01 and 1 disk inside vg02.