topic Re: new LV in Operating System - HP-UX

new LV

Bob Wallner — Thu, 07 Jun 2007 08:46:56 GMT

So, I am rebuilding an array.

I go to SAM and go to DIsk & File systems
I select create
Select teh New Volume Group
I define the New Logical Volume

Set LV name to: scratch
Set the MAx Size to the Maimum
Set the mount Directory
Changed the
Striping to 13 (13 disks) and stripe size of 64

click Add

click ok

Then it generates an error:

the command to create logical volumes, sbin/lvcreate, has failed. the stdderr output is shown below.

then it gives abrief description of the usage of the lvcreate command
followed by:
"LogicalExtenderNumber"; Must be a value between 1 & 65535

I did see any where to set that?

Signed dazed and confussed?

Re: new LV

Torsten. — Thu, 07 Jun 2007 08:52:30 GMT

Hi,

your value for LogicalExtenderNumber is probably higher than the maximum. You should increase the PE size.
Details should be mentioned in the message you've got.

Re: new LV

Bob Wallner — Thu, 07 Jun 2007 08:54:34 GMT

I wish more desritption was given in the error, but no luck.

Whewer is the PE size?

Re: new LV

spex — Thu, 07 Jun 2007 08:56:24 GMT

Hello,

I'm guessing your stripe size of 64 kbytes is too small, which is preventing lvcreate from allocating space to the desired number of extents. Try again with a bigger stripe size.

PCS

Re: new LV

A. Clay Stephenson — Thu, 07 Jun 2007 08:58:02 GMT

It's difficult to know exactly what's wrong when you use sam rather than lvcreate directly but it appears that you have chosen a size for the LVOL that is too large. The size of the LVOL is the product of the number of logical extents and the physical extent size.

You also aren't going to see any benefit from striping over 13 PV's. The gains decline rapidly once the striping exceeds 3 in most cases. Normally, in an array, you only need as many separate PV's (LUN's) as you have separate SCSI paths to the array from the hosts to distribute the i/o --- and even those gains tend to be small on most modern cache-centric arrays with Fibre SCSI.

Re: new LV

Bob Wallner — Thu, 07 Jun 2007 09:01:05 GMT

Ok, I didn't check striping thins time and got the same message.

FOr the disk size I tried a number less than the maxiumum listed. and got the same message.

Re: new LV

Torsten. — Thu, 07 Jun 2007 09:06:56 GMT

More details needed.
First, post a "vgdisplay -v" for that VG, the array model and the size of the LV you want to have.

Re: new LV

Bob Wallner — Thu, 07 Jun 2007 09:10:19 GMT

VG Name /dev/scratch
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 0
Open LV 0
Max PV 16
Cur PV 13
Act PV 13
Max PE per PV 17366
VGDA 26
PE Size (Mbytes) 4
Total PE 225719
Alloc PE 0
Free PE 225719
Total PVG 1
Total Spare PVs 0
Total Spare PVs in use 0

--- Physical volumes ---
PV Name /dev/dsk/c4t0d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c4t1d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c4t2d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c4t4d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c4t5d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c4t8d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c5t0d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c5t1d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c5t2d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c5t3d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c5t4d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c5t5d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

PV Name /dev/dsk/c5t8d0
PV Status available
Total PE 17363
Free PE 17363
Autoswitch On

--- Physical volume groups ---
PVG Name scratch
PV Name /dev/dsk/c4t0d0
PV Name /dev/dsk/c4t1d0
PV Name /dev/dsk/c4t2d0
PV Name /dev/dsk/c4t4d0
PV Name /dev/dsk/c4t5d0
PV Name /dev/dsk/c4t8d0
PV Name /dev/dsk/c5t0d0
PV Name /dev/dsk/c5t1d0
PV Name /dev/dsk/c5t2d0
PV Name /dev/dsk/c5t3d0
PV Name /dev/dsk/c5t4d0
PV Name /dev/dsk/c5t5d0
PV Name /dev/dsk/c5t8d0

Re: new LV

Bob Wallner — Thu, 07 Jun 2007 09:13:43 GMT

I am trying to create a 902824MB volume

Re: new LV

spex — Thu, 07 Jun 2007 09:16:14 GMT

> PE Size (Mbytes) 4
> Total PE 225719

An LV is limited to 65535 extents. Either manually recreate the VG and specify a larger extent size, such as 64 MB ('vgcreate -s 64 ...'), or create smaller LVs.

Re: new LV

Patrick Wallek — Thu, 07 Jun 2007 09:20:22 GMT

PE Size is definitely too small. I wold recreate the VG with a PE Size of 32 or 64.

Re: new LV

Bob Wallner — Thu, 07 Jun 2007 09:29:29 GMT

I changed teh LV and recreated it. THat seemed to work! THanks!