easy way to upgrade disk size

[Scott Van Kalken]

Girls and boys,

I have a question. What is the easiest(?) best(?) whatever way to increase size of disks.

Let's say I have a JBOD (FC-10) that has 10 disks in it.

They're full.

How would I go about putting in larger size disks?

Let's assume that the disks are mirrored so in my ten disks I have five useable at xx GB.

How would I do this with minimum fuss?

I know one way, interested to see what other people would do.

If you need more info - let me know.

[Sridhar Bhaskarla · Accepted solution]

Scott,

Take a full backup of the system.

1. Reduce the mirrors.
2. Take out the mirrored disks.
3. Replace them with bigger disks. Here is an interesting case. If you created the volume groups with default options, you cannot extend the existing volume groups with these new disks. You can, but the number of extents alloted will be equal to the number of extents that were alloted for the first disk in the volume group. If you took care of this, then you can extend the volume groups with the new disks and then extend the mirrors. Then reduce the mirrors on the old disks and replace them with new ones and mirror them again.
4. If you created the volume groups with default options before, then you cannot follow step 3. Create a new volume group with the new disks. Create file systems. Copy the data onto the new systems. Remove old volume groups and replace the disks with the new ones. Extend the new ones into the new volume groups and mirror them again.

-Sri

[Craig Rants]

Scott,
I would unmirror the disks, remove the 5 unmirrored disks, add in 5 bigger disks, mirror to those 5 bigger disks, unmirror the small disks, remove the 5 smaller disks, add in 5 bigger disks, and finally mirror to those disk.

Of course this it hightly technical description, but that in a nutshell, if I could do it, that's what I would do.

Good Luck
C

[Scott Van Kalken]

A good answer.

[Patrick Wallek]

If you used the default "Max PE per PV" value when creating the VG then you can NOT just add the larger disks to the VG. You'd just see the amount that the "MAx PE per PV" will allow. Unfortunately you can NOT increase the "Max PE per PV" value on the fly. The only way to do it is to recreate the VG.

If that is the case then you should unmirror the drives, vgreduce the unmirrored drives out of the VG, remove the old drives, insert the new drives, create a new VG, create a new LV, mount the LV as a new name, copy the data from the old drives to the new, umount both LVs, mount the new LV into the correct directory, kill the VG that the old drives belong to, remove the other old drives, put in the rest of the new drives, extend the VG onto the new drives and extend your mirrors.

You are now set

[Mary Ann Lipa]

Create an ignite tape (if you already have, skip this one).
Do a full backup of your system.
Break/Reduce the mirrors.
Remove the mirrored disks.
Replace the the 5 old disks with the 5 bigger ones.
Recreate mirror
Do the Break/Reduce,Remove, Replace steps...
then finally recreate mirror

Caveat:
If the vgs are created with the default options, you can extend the existing volume groups with these new disks, but the number of extents allocated will be equal to the number of extents that were allocated for the first disk in the volume group.

A good way to properly utilize your disk is to
Create a new volume group with the bigger disks using vgcreate with the '-e' option.
Create the file systems.
Copy the data onto the new systems.
Remove old volume groups and replace the smaler disks with the bigger disks.
Extend the larger disks into the new volume group and create mirror again.

d_b