Mirrored root volumes

[xcvzxvzxdv]

Hi I know that my service rp 3440 is having mirrored root volumes. Could anyone tell me how could I check it whether it is mirrored or not?

[Ivan Ferreira]

Use /sbin/lvdisplay -v /dev/vg00/, you will see the value:

Mirror copies

[Senthil Kumar .A_1 · Accepted solution]

Hi,

Just issue the following command.

vgdisplay -v /dev/vg00

Under Logical Volume section, If the "Allocated PE" is double of "Current LE" it means that that LV has one 1 mirror copy.Meaning it is mirrored once.If the "Allocated PE" is triple of "Current LE" it means that that LV has one 2 mirror copy.

e.g. of one way mirror...

LV Name /dev/vg00/lvol9
LV Status available/syncd
LV Size (Mbytes) 2048
Current LE 128
Allocated PE 256
Used PV 2


Similarly you can get the info from "lvdisplay command...

e.g.

root@ds12ov # lvdisplay /dev/vg00/lvol9
--- Logical volumes ---
LV Name /dev/vg00/lvol9
VG Name /dev/vg00
LV Permission read/write
LV Status available/syncd
Mirror copies 1
Consistency Recovery MWC
Schedule parallel
LV Size (Mbytes) 2048
Current LE 128
Allocated PE 256
Stripes 0
Stripe Size (Kbytes) 0
Bad block on
Allocation strict
IO Timeout (Seconds) default


Please notice the "Mirror copies" field. It says 1 here,meaning 1 way mirror. If the volume is not mirrored then the value will be "0". If it were 2 way mirror, the value would be "2". Max value can be only "2".

Regards,
Senthil Kumar .A

[xcvzxvzxdv]

Thanks for ur reply , I also have one more question. currently there is one hard disk in my server and i wanna add one more which I need to mirror. what all steps do i need to follow to create the mirror root volmes

[Senthil Kumar .A_1]

Hi,

Check this link...

For PA-RISC machines.

http://sf1000.registeredsite.com/~user793704/pdf/Manuals/LVM/RootDiskMirror.pdf

For Itanium Box,

http://h21007.www2.hp.com/dspp/tech/tech_TechSingleTipDetailPage_IDX/1,2366,5343,00.html

Regards,
Senthil Kumar .A

[Senthil Kumar .A_1]

Hi,

Please award points, if the thread has helped you.

Regards,
Senthil Kumar .A

[Ivan Ferreira]

You need to do something like this:

Mirroring root, boot and primary swap
=====================================

pvcreate -B /dev/dsk/c0t3d0
vgextend /dev/vg00 /dev/dsk/c0t3d0
mkboot /dev/dsk/c0t3d0
mkboot -a "hpux (;0)/stand/vmunix" /dev/rdsk/c0t3d0
lvextend -m 1 /dev/vg00/boot /dev/dsk/c0t3d0
lvextend -m 1 /dev/vg00/root /dev/dsk/c0t3d0
lvextend -m 1 /dev/vg00/prswaplv /dev/dsk/c0t3d0
Reactivate disks with vgchange -a y

Basically, you need to run lvextend -m 1 to any logical volume that you want to mirror. This is applicable to other logical volumes also.