topic Re: vgcreate issue in Operating System - HP-UX

vgcreate issue

fizan — Tue, 15 Jun 2010 02:53:48 GMT

# vgcreate /dev/sapvg /dev/dsk/c2t0d0
Increased the number of physical extents per physical volume to 35003.
vgcreate: Volume group "/dev/sapvg" could not be created:
VGRA for the disk is too big for the specified parameters. Increase the
extent size or decrease max_PVs/max_LVs and try again.

thanks

Re: vgcreate issue

Kapil Jha — Tue, 15 Jun 2010 03:07:08 GMT

which version of HP_UX?
you may have to use various parameter to create the vg

-e max_pe
-l max_lv
-p max_pv
-s pe_size

read man page for more information, what is the size of disk.

BR,
Kapil+

Re: vgcreate issue

fizan — Tue, 15 Jun 2010 03:41:36 GMT

uname -a
HP-UX rx260-16 B.11.23 U ia64 843 unlimited-user license
[rx260-16]/dev/sapvg
# model
ia64 hp server rx2600

Re: vgcreate issue

SUDHAKAR_18 — Tue, 15 Jun 2010 03:47:00 GMT

can u pls try with
#vgcreate -s 64 /dev/sapvg /dev/dsk/c2t0d0

if still problem exists, then increase the kernal parameter MAX_PV

Re: vgcreate issue

fizan — Tue, 15 Jun 2010 03:47:21 GMT

# vgcreate -s 16 -e 8750 /dev/sapvg /dev/dsk/c2t0d0
Volume group "/dev/sapvg" has been successfully created.
Volume Group configuration for /dev/sapvg has been saved in /etc/lvmconf/sapvg.conf
[rx260-16]/dev/sapvg
# lvcreate -L 3548 -n bineshlv /dev/sapvg
Warning: rounding up logical volume size to extent boundary at size "3552" MB.
Logical volume "/dev/sapvg/bineshlv" has been successfully created with
character device "/dev/sapvg/rbineshlv".
Logical volume "/dev/sapvg/bineshlv" has been successfully extended.
Volume Group configuration for /dev/sapvg has been saved in /etc/lvmconf/sapvg.conf
[rx260-16]/dev/sapvg
# newfs /dev/sapvg/rbineshlv
newfs: /etc/default/fs is used for determining the file system type
version 6 layout
3637248 sectors, 3637248 blocks of size 1024, log size 16384 blocks
largefiles supported

when i define with -s -e vgcreate happens why can you plz explain?
bcoz of version in 11iv3 if i give just vgcreate /dev/sapvg /dev/dsk/c0...
it use to get created.

Re: vgcreate issue

SUDHAKAR_18 — Tue, 15 Jun 2010 03:51:25 GMT

there is a limitation of max pv's.
if you have not mentioned pv size with -s option, then it will create with default pv size 4mb. but your disk size is high and max pv size exceeds in case of 11iv2 pv size is less compared to 11iv3.

Re: vgcreate issue

Kapil Jha — Tue, 15 Jun 2010 04:27:19 GMT

the parameter I listed basically decide the layout of the volume group.
how many PE per PV
how many max PV per VG.
etc etc

so by default value are very less so if u created a huge VG you will have to increase PE size,PE per PV and other things.

BR,
Kapil+

Re: vgcreate issue

Raj D. — Tue, 15 Jun 2010 05:41:03 GMT

Fizan,

> # vgcreate -s 16 -e 8750 /dev/sapvg /dev/dsk/c2t0d0

> when i define with -s -e vgcreate happens why can you plz explain?

- LVM facts:

e= default PE per PV (-e ) is 1016 ,
The maximum number of physical extents can be a value in the range 1 to 65535.

s= default PE Size (-s ) is 4MB.

- -e max_pe
Set the maximum number of physical extents that can be allocated from any of the physical volumes in the volume group. The default value for max_pe is 1016. However, if the size of any physical volume exceeds 1016 times the pe_size, the default value for max_pe is adjusted to match the physical volume size. The maximum number of physical extents can be a value in the range 1 to 65535.

- so to adjust according to this formula , you have to increase PE size or/and MAX_pe_per_PV , so that it will support according to the PV size. ( You can check the PV size with :# diskinfo /dev/rdsk/c2t0d0 ) #

Also check this out:
http://docs.hp.com/en/B2355-60130/vgcreate.1M.html

Hth,
Raj.

Re: vgcreate issue

Bill Hassell — Tue, 15 Jun 2010 12:51:26 GMT

> when i define with -s -e vgcreate happens why can you plz explain?
> bcoz of version in 11iv3 if i give just vgcreate /dev/sapvg /dev/dsk/c0...
it use to get created.

The problem is that the default sizes for vgcreate are designed for small disks, less than 100 GB. Whenever you use vgcreate, get in the habit of using -s and -e no matter what. And in order to supply the values for PEsize and maxPE, you must first determine how big the largest disk (PV) will be, not just now but in the future. If you create a VG with a 100 GB disk, then extending the VG later with a 500 GB disk will fail because the maxPE is too small.

With appropriate patches, you can use vgmodify to change maxPE but not PEsize. Try to keep the maxPE under 30-40k. The maximum is 65535 and can never be increased. It is better to have larger extents (-s 32) and a smaller PE count, especially for large disks (500-1000 GB and hgigher).