topic Re: replacing 4Gb Disks with 9Gb in Operating System - HP-UX

replacing 4Gb Disks with 9Gb

Neale Machin — Thu, 04 Jan 2001 10:08:33 GMT

we have a K370 with HPUX11 that currently has 8x4Gb disks mirrored across two HASS cabinets.
Because the disks are known to the volume groups etc as 4Gb disks I have a feeling that I will have to recreate the Vgs as well as the PVs.
Has anyone done such an upgrade or does anyone have best practice for this

Thanks

Re: replacing 4Gb Disks with 9Gb

Alexander M. Ermes — Thu, 04 Jan 2001 10:34:57 GMT

Hi there.
Is it not possible to add more disks to the HASS ? We also use these things and the disks
are HH size, so that i can put up to eight disks into one HASS.
Rgds
Alexander M. Ermes

Re: replacing 4Gb Disks with 9Gb

Victor BERRIDGE — Thu, 04 Jan 2001 10:45:12 GMT

Hi,
You would need to check the max disk size for your vg, it seems that if you let the system default, you will not be able to add 9 Gb in the same vg look through the forum for other threads on the subject...
Now there is nothing stopping you to split the mirror, replace the disks in one cab defining new vg with 9Gb disks, and mirror again,then do the same with the other subsystem...
I do this when I need to move data from one subsystem to another...
Good luck
Victor

Re: replacing 4Gb Disks with 9Gb

Bruce Regittko_1 — Thu, 04 Jan 2001 10:59:36 GMT

Hi,

When a volume group is created, the default is to set the maximum disk size to the largest being added at creation time. If you are lucky, the sys. adm. bumped up this value so your 9gb drives will work. Use vgdisplay to view the maximum number of extents allowed.

If this was not the case, see if you can create a new vg with the new disks and copy data from the old to the new.

--Bruce

Re: replacing 4Gb Disks with 9Gb

Insu Kim — Thu, 04 Jan 2001 11:20:04 GMT

This is what I'm doing.

I first insert 8GB new disk modules in the remainder slots of HASS cabinet and then do pvcreate, vgcreate, newfs and mount the new file systems on the newer mountpoint.
Finally copy everything from 4GB disks to 9GB disks using cpio.
After copy has completed, invoke one of the editors like vi and modify /etc/fstab where I remove logical volumes for 4GB disks.
Sometimes, I do vgexport/vgimport to have the same volume group numbers as previously used ones.

Regards,

Re: replacing 4Gb Disks with 9Gb

Darrel Louis — Thu, 04 Jan 2001 11:23:01 GMT

Hi,

Good idea of Victor.
But keep in mind, if the MAX-PE is not enough to add the 8Gb to a Volume group, then you need to re-create the VG with the appropiate PE-size.
This is a option you can do:
- Split the mirror
- Remove the splitted disk and add a 8Gb disk
- Create a new VG, with the 8Gb disk and enough PE, mount the VG.
- Copy data accross.
- Remove the primary LV + disk
- Add the new disk and mirror again.

Good Luck

Re: replacing 4Gb Disks with 9Gb

Neale Machin — Thu, 04 Jan 2001 12:04:35 GMT

many thanks for the responses