Adding bigger disks to vg00

[Jeremy Loukinas_1]

I am working on replacing some root disks on a k460. The disks are in vg00 they are 2 4gb disks. I am replacing them with 9's.

They are mirrored with mirror UX.

Being a Solaris admin I will try to relate how I would think it could be done..

Can I break the mirror add one of the new diks, create my filesystems on the new disk then in single user mode dd all the data over?

Is there an easier way?

Jeremy
Sunadmin@jslracing.com

[Rajeev Shukla]

There are 2 ways you can go a head.

1.
a. reduce all the mirrors in vg00.
b. reduce the vg00 and remove the mirror disk.
c. shutdown the system replace the disk.
d. do a pvcreate on this 9gb disk with -B option and start mirroring allover again and create this as an primary disk.
e. try shutdown and booting the disk with this new disk. If this are fine follow the same with the other disk.

2. second option would be to shutodwn the system replace the disk with the same ID
and then do vgcfgrestore on this new disk. And the do vgsync
this will syncronize all the mirrors.
For second option just check that you have hpux -lq.

Thanks
Rajeev

[Ravi_8]

Hi,

The Ignite option is by far the better one, and you can include all your volume groups in the backup, not just vg00 (although the vgexport command is an equally valid solution for the extra ones).

Second option is:

1.break the mirror
2.total backup of system
3.Note down the sizes of each filesystem (bdf)
4.replace the disks
5.just install the OS and create/increase the file system to the values noted in step 3
6. restore from backup
7.mirror the disk to the second

[T G Manikandan]

IGNITE is the best way for the process.

Take two ignite backup tapes of the existing vg00 volume group.
shutdown and replace the drive.
Boot from the ignite tape and restore the vg00 configuration into the new disks.

check this hpdoc which can help you

http://www1.itrc.hp.com/service/cki/search.do?category=c0&mode=id&searchString=UIUXKBRC00010068&searchCrit=allwords&docType=Security&docType=Patch&docType=EngineerNotes&docType=BugReports&docType=Hardware&docType=ReferenceMaterials&docType=ThirdParty

[James R. Ferguson · Accepted solution]

Hi Jeremy:

Use Ignite to recreate your vg00. Breaking a mirror, adding a larger size physical disk, and re-mirroring does not change the original limits of the LVM geometry. It is only during a 'vgcreate' that the 'max_pe' and 'pe_size' are established. Thereafter the original values are applied during any 'vgextend'. If default values were used with your 4GB disks you will likely find that about 1GB of your 9GB disk will be inaccessible (insufficient PEs). Have a look at the man pages for 'vgcreate' for more information.

Download current Ignite software (including documentation) from here:

http://www.software.hp.com/products/IUX/index.html

Use 'make_tape_recovery' to create a tape archive for all of vg00.

# make_tape_recovery -x inc_entire=vg00 -I -v -a /dev/rmt/0mn

Boot from the tape, choose the Advanced Installation option targeting your new disk. You can resize your filesystems too during this process.

Regards!

...JRF...

[pap]

HI Jeremy,
You can do following as well.

1. Shutdown the system and install two 9GB disks in the machine.

2. Boot the system.

3. Add 9GB disks to vg00 by running vgextend command. use pvcreate -B option for one of the disk.

4. Break the mirrors.

5. use pvmove to move the data from original root boot disk to 9GB disk ( which has been created using pvcreate -B option)

6.once the pvmove ran successfully you can go ahead and repeat the same thing for second 9 GB disk to create the mirror.
7. Finally remove the 4 GB disks from the system using vgreduce /dev/vg00 .......

This works well if you try it. This procedure is the simplest procedure. Make sure you follow correct steps which creating the physical volumes and mirrors.
It is best if you can take Ignite tape for the system first before going ahead with above solution.

Thanks,

-pap

[Anthony deRito]

IGNITE is realy the way to go... even if you don't decide to use it in this situation, it's a good idea to create tape archives of your boot disk with IGNITE. It can save you a lot of trouble if/when your boot disk is unbootable. If your interested in resizing your filesystems, this is easy to do with IGNITE as mentioned.

http://software.hp.com/products/IUX/

[Deshpande Prashant]

Hi
If you are replacing the 4GB disk with higher capacity disk, using Ignite-UX will be safest way to do it.

Thanks.
Prashant.

[Dave Wherry]

Make sure you go with the James Ferguson post. It's the only one that mentions the max_pe problem that is quite common with adding larger disks to an existing volume group.

[Steven E. Protter]

The nice thing about the Ignite tape is after booting, you can get to an interface just like the OS install screen and increase the size of the root fs, /var or make any other tweaks you wanted to make.

After the ignite boot, there is an interface that lets you interupt and modify the installation.

I used it to get around making the root fs to small on a new system, an ignite server.

Your solaris approach is fine, and the reduce option is the same thing. Ignite is just a better tool for the same job.

Steve