Adding physical disk to volume group

[Brian Bientz]

Currently we have one main volume group that is made up of three physical volumes. One of the physical volumes is a 180 GB raid 5 array.

Is it easy to add additional drives to the physical volume?
What steps are required to add one or two additional drives? Does RAID array have to be rebuilt?

Forgive me if some of this doesn't make since. I am a DBA ... not a UNIX SysAdmin.

Thanks in advance for any advice.

[Stuart Abramson_2]

Here are some steps. This is complicated if you aren't a UNIX System Admin.

If you want more detailed info, I can attach it:

1. Do an ioscan and check for available disks.
2. Verify that the "available" disks are not used on ANOTHER system. Many disks can be presented to multiple systems.
3. Bring up sam in a graphical window.
4. Have sam check for available disks.
5. Use the sam feature to add disks to VGs.
6. Creat new Logical Volume on new disk, or extend existing logical volumes to new disk. (Use sam.)
6. Do you use "raw" filesystems or mounted file systems.
7. If mounted, create new filesystems, or extend existing file systems onto new disk.

If you don't have any "unused" disks, then you have more work ahead of you, which depends on the vendor and model of disk that you have. What kind of disk is it?

[Brian Bientz]

I don't believe that we have any unused disks.

We are using StorageWorks SAN from Compaq.

[Rita C Workman]

Well I must ask this...one main volume group, you say -
Is that volume group vg00??

If it is and you have extended vg00 out to an external disk array...hmmm...maybe some folks are okay with this...not my preference.

If it is something other than vg00, then my next question becomes...What software are you running? MC/SG by any chance?

And lastly....you ask about adding drives to the physical volume? Are you asking to add physical volumes to the volume group - or - add more physical disk to the array?

I'm trying to improve my listen while I read skills...so before I answer I want to be sure I have your needs...exactly.

Let us know,
Rita

[Sunil Sharma_1]

Hi,

I think you are asking about adding another disk in Disk array and configuring it as a part of Raid-5 volume.

It all depends on your Disk array capabilities if it allowing you to add a disk in Raid-5 volume without recreating raid then it's not a problem other wise you can do 2 things.

1. Add new disks in array and configure them as new lun (it has to be done in Array) then add thoes disks in same volume group using LVM commands.
in this case you may do compromise with data security.
2. take a full backup then add new disk in array and rebuild LUN using old and new disks
and restore data back but this will be time consuing work..
Sunil

[Brian Bientz]

In response to Rita's questions:

* There are two volume groups vg00 and vgprod. Sorry to mislead you.
* Yes, we are running MC/SG.
* We need to add more physical disk to the array.

Thanks.