PE extent size

[himacs]

Hi Admins,

Please let me know the advantages by increasing the PE size from default value(4 MB) during vgcreate.

Regards
himacs

[Patrick Wallek]

A larger PE size allow for use of larger disks.

[himacs]

Hi Patrik,

Thanks for the response.

But your answer is not clear.
Can you please elaborate it..

M asking what is the use of 16 or 32 MB PE over 4MB

Regards
Pavan

[Asif Sharif · Accepted solution]

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1404400

[Bill Hassell]

4 MB is very small and since there is an unchangeable limit of 65535 extents for a physical volume (disk or LUN), then you cannot use large disks (500 GB and larger) without changing the PE size. It's very important to change the PE size with vgcreate unless you *know for sure* that this volume group will never have larger disks added at a later date. You cannot change the PEsize on an existing volume group.

[P Muralidhar Kini]

Hi himacs,

For more information on VGMODIFY -
http://docs.hp.com/en/B2355-60130/vgmodify.1M.html

PE Size and its modification -
http://forums11.itrc.hp.com/service/forums/questionanswer.do?admit=109447626+1274786523484+28353475&threadId=1294182

Hope this helps.

Regards,
Murali

[Kranti Mahmud]

Hi Himacs,

check the below thread:

http://forums11.itrc.hp.com/service/forums/questionanswer.do?admit=109447626+1276519248349+28353475&threadId=518894

Rgds-Kranti

[Bill Hassell]

> vgmodify...

Note: this is a relatively new command and may not be available on older systems. And vgmodify cannot change the volume group's PEsize.

[johnsonpk]

Adding to Bills earlier comment ,


PE size also defines your maximum LV size that can be created in the VG

For example, If the PE size is 4MB for a VG , The maximum size of LV that you can have is 4*65535 (ie 256 GB).

Regards!
Johnson