How to change max lv, max pv, max PE per PV.

[senthil_kumar_1]

Hi

There is one vg in my hp-ux 11.11.

Ex:
# vgdisplay -v

VG Name /dev/vg13
VG Write Access read/write
VG Status available
Max LV 24
Cur LV 24
Open LV 24
Max PV 16
Cur PV 16
Act PV 16
Max PE per PV 2432344
VGDA 2
PE Size (Mbytes) 8
Total PE 25596
Alloc PE 24750
Free PE 846
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0


I have following questions.

1) How change the max PE per PV after creating the volume group?

2)is max PE per pv is 65536?

3) cam we change max PE per PV above 65536?

4) so max size of a PV is 525GB with 65536 and 8MB size?

5) defaultly max PE per PV is 1016?. so if we did not mention max PE when creating Vg. then the default value set to 1016? so max size of pv is 8GB with 1016 PEs and 8 Mb size?

6) so do we have to mention the max PE per PV using -e option with vgcreate command?

7) what is the max size of a VG in hpux?

8) what is the max size of a VG in linux?

9)is Total PE per PV is now allocated?

10) is max PE per PV is maximum PE that a PV can have?

[James R. Ferguson · Accepted solution]

Hi:

Before 11.23 (with patches) or before 11.31 (intrinsically) in order to modify a volume group's geometry, you are limited to destroying and recreating the volume group. During 'vgcreate' you have the ability to specify its characteristics.

The limits for the various parameters are described in the manpages:

http://docs.hp.com/en/B2355-60127/vgcreate.1M.html

...and/or:

http://docs.hp.com/en/6054/LVM_Limits_White_Paper_V4.pdf

Regards!

...JRF...

[Taifur]

Hi Senthil,

During PV ,VG create time you have to mention the limit as your requirement, SO, you can check below link regarding this issue.

http://docs.hp.com/en/B2355-90692/vgcreate.1M.html

http://docs.hp.com/en/B2355-90691/lvcreate.1M.html

Rgds//
Taifur

[Sajjad Sahir]

Dear Senthil

Please the man pages of vgcreate

during volume group creation u have a lot of optin regarding maximum pv, max physical extents etc...


thanks and regards

Sajjad Sahir

[Jestin John Chacko]

Dear Senthil,

I think this document will help you in clarifying your errors regarding lvm in 11iv3 of hp ux

http://docs.hp.com/en/5992-3385/index.html

[Rahul Rai_1]

Hi Senthil,

good to know you are eager to know about LVM,

as per your question:-

1) How change the max PE per PV after creating the volume group?
Ans:- you can not change the max PE or PV after creating VG, you
can change while you are creating PV and VG at that time there is
lots of options is given.

2)is max PE per pv is 65536?
Ans:-No, before to know this, lets be discuss about PE and PV

PE is physical extent as you know, and this is the smallest amount
of disk space which can be allocate to lv

PV this is the actuall disk
your answer is 2432344, as it is allready mention in ur question

3) cam we change max PE per PV above 65536?
Ans:- No you can not, untill if you have chance to create PV,VG.

4) so max size of a PV is 525GB with 65536 and 8MB size?
Ans:-Nothing to worry, just multiply with PE size with max PE per PV

5) defaultly max PE per PV is 1016?. so if we did not mention max PE
when creating Vg. then the default value set to 1016? so max size of
pv is 8GB with 1016 PEs and 8 Mb size?

Ans:- did not get you, sorry!

6) so do we have to mention the max PE per PV using -e option with
vgcreate command?
Ans:-yes absolutly you are rite, vgcreate -e

7) what is the max size of a VG in hpux?
Ans:-Default is 10 and max is 256.

8) what is the max size of a VG in linux?
Ans:-again 256 if I am not wrong.

9)is Total PE per PV is now allocated?
Ans:-Look total PE is the size which is the max size which you can use

10) is max PE per PV is maximum PE that a PV can have?
Ans:- yes you can say :)

and please go through the document which you have from the team.

Regards,
Rahul Rai.

[Basheer_2]

James and Rahul have provided very good info.
My comments

MAX Size-of-the-disk = MAX PE/PV * PE-SIZE

PE size couldn't be changed before 11.23

vgcreate flags
-e extents
-s PE SIZE (4,8,16,32,64 You can specify any of them)

5) default is not 1016. This depends on the FIRST disk that you included in the vgcreate cmd. if you dont specify the size, it will use the FIRST biggest disk.

[Bijeesh]

hi
for quick refference find the attachment