topic Re: EVA 300 -LVM Extend in Operating System - HP-UX

EVA 300 -LVM Extend

dunefremen — Wed, 15 Nov 2006 18:46:19 GMT

Hello all,

Please help me clarify the steps to follow before i'll do someting wrong.
At our site we need to extend one logical volume.
The scenario is as follow:
-We have a EVA, which we administer using HP Storage Works. We have been allocated some space - 100 Gb, but after some time we need more space. We need to increase the space for our database.
Using Storage Works we have been alocated the space, restarted HP-Ux server. Using SAM, "Disks and File Systems" > "Disk Devices" we see now the correct, increased size for disk device:
255/255/0/0.0 1 LVM vgbd 300496 hp StorageWorks
I need to know, what is the corect order of things to do for increasing my logical volume, as my volome group is stil on old size -100Gb.

I think following commands will help:

vgdisplay -v /dev/vgbd
--- Volume groups ---
VG Name /dev/vgbd
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 1
Open LV 1
Max PV 16
Cur PV 1
Act PV 1
Max PE per PV 3275
VGDA 2
PE Size (Mbytes) 32
Total PE 3275
Alloc PE 3125
Free PE 150
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0

--- Logical volumes ---
LV Name /dev/vgdb/lvbd
LV Status available/syncd
LV Size (Mbytes) 100000
Current LE 3125
Allocated PE 3125
Used PV 1

--- Physical volumes ---
PV Name /dev/dsk/c10t0d0
PV Status available
Total PE 3275
Free PE 150
Autoswitch On

ioscan -fnkC disk

Class I H/W Path Driver S/W State H/W Type Description
==========================================================================
disk 1 1/0/0/3/0.6.0 sdisk CLAIMED DEVICE HP 146 GMAW3147NC
/dev/dsk/c0t6d0 /dev/rdsk/c0t6d0
disk 0 1/0/0/3/1.2.0 sdisk CLAIMED DEVICE _NEC DVD_RW ND-3550A
/dev/dsk/c1t2d0 /dev/rdsk/c1t2d0
disk 2 1/0/1/1/0/1/1.6.0 sdisk CLAIMED DEVICE HP 146 GMAW3147NC
/dev/dsk/c3t6d0 /dev/rdsk/c3t6d0
disk 3 255/255/0/0.0 sdisk CLAIMED DEVICE HSV100 HP
/dev/dsk/c10t0d0 /dev/rdsk/c10t0d0
disk 4 255/255/0/0.1 sdisk CLAIMED DEVICE HSV100 HP
/dev/dsk/c10t0d1 /dev/rdsk/c10t0d1

Thanks. Best regards,

Re: EVA 300 -LVM Extend

Yang Qin_1 — Thu, 16 Nov 2006 03:32:31 GMT

You have a limitation "Max PE per PV 3275" that is 32MB x 3275 = 104800 MB. So with current VG configuration, you cannot extend lvbd to 300 GB. To change "Max PE per PV" you need to recreate you VG with -p option.

Yang

Re: EVA 300 -LVM Extend

nishith — Thu, 16 Nov 2006 10:43:30 GMT

hi buddy!

you certainly have the restriction with respect to "Max PE per PV 3275" for this VG. Hence as mentioned you cannot increase the size of your VG more than ~100GB.

To avoid this situtions in future create VG with higher values (refer man pages) on options '-e' and '-s' i.e., ('e' max_pe) & ('s'= pe_size).

But you need not recreate this VG as it could be time consuming (taking backup & restoring).

Better way would be as below.

1)since the restriction is per PV only,
create TWO new V-disks in EVA 3000 & present to this host.

2)use pvcreate on this new disk devices.
#pvcreate /dev/rdsk/cXtYdZ ( use the ur dev file)

3)Then extend the VG using this TWO PVs.
#vgextend /dev/vgbd /dev/dsk/c9t0d1 /dev/dsk/c9t0d2 ... (example)

4)next extend the LV (lvdb)
#lvextend -L 300000 /dev/vgdb/lvbd

5)Last extend the filesystem.
# umount /filesystem
#extendfs -F vxfs /dev/vgdb/lvbd

regds,
nishith

Re: EVA 300 -LVM Extend

Patrick Wallek — Thu, 16 Nov 2006 10:50:32 GMT

Did you increase the size of the existing LUN on the EVA? Or did you add a new LUN?

If you increase the size of the existing LUN, then you just wasted space. HP-UX does NOT support increasing the size of a LUN, and then increasing the disk size in LVM. That doesn't work.

The way to do it is to add a NEW LUN to the EVA, present it to the HP-UX server, extend the VG and then increase the size of the LV.