topic Re: Extending LUNS in Operating System - HP-UX

Extending LUNS

Kwahae_1 — Fri, 22 Jun 2007 16:15:56 GMT

Hi all,

I ran out space on one my VGs but managed to add some LUNs as metaLuns on a CX7000.

HP-UX 11iv2 SAM disk devices show:

Hardware path: 0/1/0/0.3.0.0.0.0
# of paths: 8
Use: LVM
Volume group: vgfn
Total megabytes: 302080
Description: DGC CX700WDR5

vgdisplay -v vgfn ------- output

--- Volume groups ---
VG Name /dev/vgfn
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 3
Open LV 3
Max PV 16
Cur PV 1
Act PV 1
Max PE per PV 46080
VGDA 2
PE Size (Mbytes) 16
Total PE 11518
Alloc PE 11514
Free PE 4
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0

--- Logical volumes ---
LV Name /dev/vgfn/oralv1
LV Status available/syncd
LV Size (Mbytes) 30000
Current LE 1875
Allocated PE 1875
Used PV 1

LV Name /dev/vgfn/oralv2
LV Status available/syncd
LV Size (Mbytes) 20480
Current LE 1280
Allocated PE 1280
Used PV 1

LV Name /dev/vgfn/fnlv1
LV Status available/syncd
LV Size (Mbytes) 133744
Current LE 8359
Allocated PE 8359
Used PV 1

--- Physical volumes ---
PV Name /dev/dsk/c32t0d0
PV Name /dev/dsk/c34t0d0 Alternate Link
PV Name /dev/dsk/c36t0d0 Alternate Link
PV Name /dev/dsk/c38t0d0 Alternate Link
PV Status available
Total PE 11518
Free PE 4
Autoswitch On

I am new to LVM and wondering how I should proceed to add the newly created space to LV fnlv1 or am restricted by the max PE business.

Thanks in advance

Re: Extending LUNS

Tim Nelson — Fri, 22 Jun 2007 16:21:49 GMT

I only see one device in this volume group.

Did you extend the LUN cooresponding to c32t0d0 or are you looking to add another LUN, have two devices and then extend the LVOLs to the next device ?

Re: Extending LUNS

Sandman! — Fri, 22 Jun 2007 16:25:34 GMT

The LUNs created on the DGC CX700WDR5 need to be pvcreate'd; added into the VG with vgextend and lvextend fnlv1 viz.,

# pvcreate /dev/rdsk/c#t#d#
# vgextend vgfn /dev/dsk/c#t#d#
# lvextend -L /dev/vgfn/fnlv1

Re: Extending LUNS

Kwahae_1 — Fri, 22 Jun 2007 16:42:06 GMT

Hi Tim,

The extension was made to /dev/dsk/c32t0d0 and it shows the new value of ~300GB as in the SAM output. Now how do I add the extra space to lvol fnlv1 because as you rightly said there is only one device.

Re: Extending LUNS

Sandy Chen — Fri, 22 Jun 2007 22:14:49 GMT

Hi,

Are you expanding the size on the same LUN? As far as I know, HPUX is not support this. You cannot use the expanded disk.

What you should do is adding another LUN and assign the LUN for the server. It will be recognized as a new disk. And then do vgextend, lvextend and extendfs.

Regards,
Sandy

Re: Extending LUNS

Sandman! — Fri, 22 Jun 2007 23:07:08 GMT

Increasing the LUN size on the storage array will not make it visible to the LVM of HP-UX. Atleast not the HP-UX version that you are currently running. To have that feature you would need HP-UX version 11.31.

~hope it helps

Re: Extending LUNS

Duncan Edmonstone — Sat, 23 Jun 2007 02:54:54 GMT

Actually you *can* now change the LUN size in LVM on 11iv2 as well as 11iv3.

You need the following patches:

PHCO_35524
PHKL_36244

Then have a read of the whitepaper that describes how to do it (and learn a lot about LVM in the process)

http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01920387/c01920387.pdf (BSC link updated by admin)

HTH

Duncan

Re: Extending LUNS

Kwahae_1 — Sat, 23 Jun 2007 12:22:36 GMT

Thanks guys. Before I go Duncan's way, I believe Sandy and Sandman are suggesting that since SAM can see the expanded LUN, the only way I can get to it via LVM is backup my current vg, recreate it with the bigger size and then restore?

Duncan's way is neat but I have had nasty patch experiences before and hence preference for other solution. Hereunder is my ioscan and would appreciate if I could have the full comand set for the backup and restore solution.

Thanks again.Class I H/W Path Driver S/W State H/W Type Description
===========================================================================
disk 0 0/0/1/1.2.0 sdisk CLAIMED DEVICE HP 36.4GATLAS10K3_36_SCA
/dev/dsk/c1t2d0 /dev/rdsk/c1t2d0
disk 1 0/0/2/0.2.0 sdisk CLAIMED DEVICE HP 36.4GATLAS10K3_36_SCA
/dev/dsk/c2t2d0 /dev/rdsk/c2t2d0
disk 2 0/0/2/1.2.0 sdisk CLAIMED DEVICE HP DVD-ROM 305
/dev/dsk/c3t2d0 /dev/rdsk/c3t2d0
disk 85 0/1/0/0.3.0.0.0.0.0 sdisk CLAIMED DEVICE DGC CX700WDR5
/dev/dsk/c32t0d0 /dev/rdsk/c32t0d0
disk 86 0/1/0/0.3.0.0.0.0.2 sdisk CLAIMED DEVICE DGC CX700WDR5
/dev/dsk/c32t0d2 /dev/rdsk/c32t0d2
disk 87 0/1/0/0.3.1.0.0.0.0 sdisk CLAIMED DEVICE DGC CX700WDR5
/dev/dsk/c34t0d0 /dev/rdsk/c34t0d0
disk 88 0/1/0/0.3.1.0.0.0.2 sdisk CLAIMED DEVICE DGC CX700WDR5
/dev/dsk/c34t0d2 /dev/rdsk/c34t0d2
disk 89 0/10/0/0.4.0.0.0.0.0 sdisk CLAIMED DEVICE DGC CX700WDR5
/dev/dsk/c36t0d0 /dev/rdsk/c36t0d0
disk 90 0/10/0/0.4.0.0.0.0.2 sdisk CLAIMED DEVICE DGC CX700WDR5
/dev/dsk/c36t0d2 /dev/rdsk/c36t0d2
disk 91 0/10/0/0.4.1.0.0.0.0 sdisk CLAIMED DEVICE DGC CX700WDR5
/dev/dsk/c38t0d0 /dev/rdsk/c38t0d0
disk 92 0/10/0/0.4.1.0.0.0.2 sdisk CLAIMED DEVICE DGC CX700WDR5
/dev/dsk/c38t0d2 /dev/rdsk/c38t0d2

Re: Extending LUNS

Sandman! — Sat, 23 Jun 2007 19:13:30 GMT

From the ioscan output it looks like you have another LUN, /dev/dsk/c32t0d2, available onto which lvol fnlv1 can be extended. Verify that /dev/dsk/c32t0d2 is empty or not in use and then do steps below:

# pvcreate /dev/rdsk/c32t0d2
# vgextend /dev/vgfn /dev/dsk/c32t0d2
# lvextend -L /dev/vgfn/fnlv1

Re: Extending LUNS

Kwahae_1 — Sun, 24 Jun 2007 04:13:34 GMT

Hi Sandman,
I suspected there was something like that but how do I find out this LUN or disk is empty or not in use? Sorry for the bother. Newbie!
Thanks.

Re: Extending LUNS

skt_skt — Sun, 24 Jun 2007 16:10:48 GMT

pvdisplay
strings /etc/lvmtab|grep cxtydz
This will help to identify if the disk is in use or NOT on that particular server.

Re: Extending LUNS

Sandman! — Sun, 24 Jun 2007 21:14:39 GMT

The device /dev/dsk/c32t0d2 maybe in use by any server which is zoned to access it since your storage is on a SAN. One way to ascertain that is to see if this PV has a VGID assuming that you are using HP's LVM and not VxVM as your volume manager. The command below will display the VGID stamped on the PV.

# echo '0x2010?2X' | adb /dev/dsk/c32t0d2

If the output of the above command is

2010: 0 0

then the PV is not part of any VG and does not contain any data unless it is being used for raw storage by a database. Ask your DBA whether that is the case or not? Once these two scenarios are clarified you can proceed with the steps mentioned in the previous post.

~hope it helps