Add mirror to DLVM

[Truchet Mathieu]

Hi,

I'm using MC Service Guard on N-Classes. The 2 machines are duplexed and use 11 external HDs (their usage is DLVM !) : they all are mirrored one to one, except one (that's why 11). I have a new HD plugged into the machines and I want it to be the mirror disk of the alone one.
How can I configure it ? I've read that SAM cannot be used to perform this operation (because of DLVM).
Is there a solution ?

Thanks.

[Mark van Hassel · Accepted solution]

Hi,

It seems that you are using some sort of disk array. If this is the case mirroring is configured with the array tools instead of Mirror-UX (host based mirroring). So the question is : which array are you using ?

[Truchet Mathieu]

The disk array is a SC10. Does it fit with your question ?

[Mark van Hassel]

The I'll assume you have two SC10's, because they can only fit 10 disks. Anyhow, in this case you use host based mirroring and thus the logical volumes are mirrored i.s.o. the disks.
Add the new disk to the vg of the lvols that are not mirrored:
pvcreate /dev/rdsk/cZtYdZ
vgextend vgname /dev/dsk/cXtYdZ

and for each lvol:

lvextend -m 1 /dev/vgname/lvolname /dev/dsk/cXtYdZ


Hope this helps.

[Bill McNAMARA_1]

ioscan -fnkCdisk
to see the device files of your disk.
You should refer to the sc10 manual/sam inerface to figure out the id of the new disk/enclosure if you don't know it already.

pvcreate and vgextend to add the new disk to the vg or use vgcfgrestore if you replaced a disk that was already previously configured.

You can use pvmove to push an lvol from one disk to another if you really want to specify otherwise you'll have to lvcreate a null size, extend onto a specific disk and then lvextend the mirror onto the newly added pv and then lvextend your mirror as mentioned above.

lvdisplay -v to verify it's all as you expect!

Later,
Bill

[AlHassani Mohamed]

Hi Mathieu,
Caution, il faut faire attetion.
You must after extend the Volumegroup and the Logical Volume, adapting the Volume Configuration on the Backup server. yo can do follow:
1.) on Primary server
vgexport -p -s -v -m vgxx.mymap /dev/vgxx
copie the created mapfile via ftp or RCP on the backup server.
2.) on backup server
vgexport /dev/vgxx
mkdir /dev/vgxx
mknod /dev/vgxx/group c 64 0x0n000
vgimport -s -v -m vgxx/mymap /dev/vgxx
gut luck
bonne chance

[Truchet Mathieu]

Thanks all for your answers, it helps me very well.