topic Re: Disk size Sam vs pvdisplay in Operating System - HP-UX

Disk size Sam vs pvdisplay

James Odak — Mon, 17 Jul 2000 14:58:03 GMT

This is interesting
If i go into sam
Disks and file systems
Disk devices
device 10/0.1.0 c4t1d0 shows phsical Mbytes of 8680

but when i use the command
pvdisplay -v /dev/dsk/c4t1d0
it gives me a PE of 1085 x4 = 4340
lvdisplay tells me its not mirrored and gives me the smaller size as well

so why does sam report the drive being twice as big? and which is correct?

Re: Disk size Sam vs pvdisplay

Antoanetta Naghiu — Mon, 17 Jul 2000 15:17:05 GMT

Are the PE size 4 MB? If yes, check the paches (for HP-UX 11.0 PHCO_18485 LVM commands cumulative patch and its dependences).

Re: Disk size Sam vs pvdisplay

Rick Garland — Mon, 17 Jul 2000 15:20:21 GMT

Was the disk replaced with another smaller disk? What is diskinfo stating?

Re: Disk size Sam vs pvdisplay

James Odak — Mon, 17 Jul 2000 15:33:19 GMT

im running 10.20 actually
the drive has a 9.1gb sticker on it
so ive been asumming that sam is correct

problem is i have been wanting to mirror this drive
it is posible this drive has been replaced
its in a cage with 2 4.0gb drives and a 4.3 that shows as 4.0 on sam and pvdisplay

confusing

Re: Disk size Sam vs pvdisplay

James R. Ferguson — Mon, 17 Jul 2000 15:57:05 GMT

James:

Per chance do you have alternate links? If so, are your SAM patches current?

...JRF...

Re: Disk size Sam vs pvdisplay

Antoanetta Naghiu — Mon, 17 Jul 2000 15:58:32 GMT

Do you have installed PHCO_18563?
Patch Description: s700_800 10.20 LVM commands cumulative patch. Patch Dependencies: s700: 10.20: PHKL_13247 s800: 10.20: PHKL_13248.

Re: Disk size Sam vs pvdisplay

Patrick Wessel — Mon, 17 Jul 2000 15:59:41 GMT

James,

I think your replaced a 4.3Gbyte disk with this one, and restored the 'old' LVM information to this disk.
A diskinfo/dev/rdsk/c?. should show you the 'right' size of this disk. I'm afraid you have to do a pvcreate -f on this disk to use the whole size of it.

Re: Disk size Sam vs pvdisplay

James Odak — Mon, 17 Jul 2000 17:19:57 GMT

There is a good chance this drive was replaced, i only took over on this job a few months ago
i guess i need to start chekcing patches

Re: Disk size Sam vs pvdisplay

Dave Wherry — Mon, 17 Jul 2000 17:50:47 GMT

I believe it might be related to your max pe setting in the volume group definition. What I think happened is your volume group was created with a 4.3GB disk and the default for max pe was accepted. That means you can only use 4.3GB disks in that volume group. Or I should say, 4.3GB of a disk. What then happened was the 9GB drive was added to or replaced a 4.3GB in the volume group. LVM will only let you use the first 4.3GB. That is the difference in the numbers you see.
The only way to use the full 9GB of that drive is to rebuild the volume group. Backup your data, delete the volume group and recreate it and your logical volumes. Then restore your data.
I always like to set the max pe high when creating a volume group. Next time you want to add a disk it might be an 18GB or 36GB or who knows what's coming next. Do not set artificial limits too low.
Check your max pe by doing a vgdisplay on the volume group and I think you will see your limit.

Re: Disk size Sam vs pvdisplay

Eddie Warren — Mon, 17 Jul 2000 19:37:34 GMT

Hi James,
Looks like Dave hit the nail on the head. It looks like the original volume-group was created with 4.3gb disk/drive. The previous SA added a 9.1gb disk/drive to the volume group, by doing this the new 9.1gb drive was limited to the max_pe of the original drive. Which means you will only get to use 4.3gb of the 9.1gb of space.
To get around this you could backup the data in the volume group. recreate the VG using the 9.1gb drive as the primary drive.
Good job Dave.