Moving array from one server to another

[Steve Krengel]

I've got two similarly configured DL380G2 servers - dual proc, 1GB RAM, 5302/64 controller, mirrored 18GB OS volume.

One server has a 4-disk RAID 5 array using 18GB U3 drives with approximately 40GB of data.

The other has a 4-disk RAID 5 array using 72GB U3 drives and it is completely empty.

I want to swap out the 18GB drives with the 72GB drives to make more room available.

What's the easiest way to go about this? Remove the 18GB drives, put in the new 72's, create the volume and restore from tape?

Could I create the array on the second server, copy the data over from the first server and then simply plug the new drive in the old server?

[Ted Ellis_2]

are the arrays the same, save the disk sizes? If they are, then I think configuring everything you want on server 2 followed by a vgexport/vgimport would work well. We have done that in the past here. It would require some shutdowns to handle disconnecting, swapping and reconnecting the arrays. IN fact, if you go through the steps to vgexport with a map file the 40 GB volume group on server 1 (and make sure you label all cable connections), then when this is vgexported, it would be in a state to be recovered if something goes wrong. Just protect the map file with your life. On server 2, you get everything the way you want it with the volume group, then vgexport with map file. Get this map file to server 1... and vgimport the new volume group after you have moved the array from server 2 to server 1. If you have any questions about vgexport/vgimport/vgchange... fire away.

No matter what you decide... also get a full backup of the 40 GB you are trying to migrate

Ted

[Steve Krengel]

Ted,

Thanks for the reply. I guess I should have specified we are on a Windows 2000 environment! Sorry about that....

Steve K.

[Ted Ellis_2]

uhhggg! I punt on that note... or am left with backup, swap hardware, restore

Ted

[ENieves]

I came here looking for answers to the same question.

I don't believe there is an easier way than what you stated about restoring from backup after the array was created with the larger disks.

I'll be keeping an eye open for late breaking developments.

[Janine Bertolo]

In most cases, you can down the server, remove one smaller drive, replace it with a larger one, reboot and let the array rebuild to the larger drive.

Repeat this process until all the drives in the array have been replaced with larger drives.

When that's done, you can extend or add a logical drive to the array using the Array Configuration Utility and access the free space from your OS.

This process takes more time, but eliminates the need to restore from backup. Users can access the server the full time the rebuild is happening. Of course it's always best practice to have a recent backup available.

Specific details to your build are always helpful, but those are the rules in general.

Even Windows2000 with SP3 supports logical drive expansion according to Microsoft.

Hope that helps,

Janine

[Michael Steele_2]

Here is a summary of the procedure to follow:


a) vgreduce out one disk from each volume group. This will be the last disk added which means it could either be the alternate or primary. Meaning it may not always be the alternate, but the last disk added.

vgdisplay -v (* all vg's will be reported. *)

vgreduce /dev/vg## /dev/vg##/c....

b) Detach the fiber from old array and reattach it to the new array.

Both arrays are now attached.

c) ioscan, insf -e, etc. Verify you can see the new disk on the new array.

d) vgcreate a new volume group on the server using the new primary disks only. Don't add in the alternates yet. (* Of course, you won't be able to ...*)

vgcreate /dev/vg##_new /dev/dsk/c..., etc.

e) Create and mount filesystems.

f) Copy the filesystem data from into temporary filesystems. Use "...cksum..." to verify.

h) Modify /etc/fstab so new logical volumes of new array and new volume group are substituted with old logical volumes from old array.

i) vgreduce out the old array volume groups and use the new arrays volume group.

Note, your file system mount points have not changed.

j) Swap out the fiber from old array to new on the last fc and add in the new alternate array disks.

[Michael Steele_2]

Regarding:

a) vgreduce out one disk from each volume group. This will be the last disk added which means it could either be the alternate or primary. Meaning it may not always be the alternate, but the last disk added.

vgdisplay -v (* all vg's will be reported. *)

vgreduce /dev/vg## /dev/vg##/c....



Let me clarify this a little more. You have to reduce everything off of one fibre channel adapter.

[Michael Steele_2]

Oops. I just noticed the Proliant. You probably don't even have LVM and that's what my postings address. Please ignore them and any confusion I may have caused. (* Multi tasking with my daughter today. *)