From: Phillips_Sean@emc.com
Date: Wed Apr 27 2005 - 08:53:15 EDT
Also, please visit this whitepaper at
http://docs.hp.com/en/6054/Limits_wp.htm
<http://docs.hp.com/en/6054/Limits_wp.htm> to review LVM limitations and
behaviors.
Thanks to V.T. Mueller for this link.
-----Original Message-----
From: Phillips, Sean
Sent: Wednesday, April 27, 2005 7:22 AM
To: 'hpux-admin@dutchworks.nl'
Cc: Khan, Malik
Subject: SUMMARY: extending a VG with larger volumes using LVM
Many thanks to those who replied - and fast!
Jeff Fisher
Baranyai Pal
Eef Hartman
Stefan Farrelly
The consensus is that the Max PE per PV size is fixed at creation, which
defaults to the PV size of the first disk added to the group. This can be
modified at vgcreate time, but unless you had the foresight to know you
could be adding larger volumes later, you're up a creek.
A reference was made to the 'vgmodify' command which sounds like it allows
one to deactivate the VG and then change the max extents, but it's private
(non-published). This option does sound sweet and it brings up questions
about support from HP for that option. If it's a large high-profile
customer, will they support it?
---- original post -----
Gurus,
Postings in the archives seem to indicate that LVM may have 'issues' when
extending a VG with larger PV's than it's presently configured with.
In my case, we have 4x12gb LUNs. We want to add 3x68gb LUN's as a mirror
during a migration, and eventually expand the LV's on the remaining PE's.
Here's the preliminary plan:
1. Existing disks are /dev/dsk/c4t1d1 /dev/dsk/c4t1d2 /dev/dsk/c4t1d3
/dev/dsk/c4t1d4
2. # vgextend vg01 /dev/dsk/c1t1d1 /dev/dsk/c1t1d2 /dev/dsk/c1t1d3
3. # lvextend -m 1 /dev/vg01/lv01 /dev/dsk/c1t1d1 /dev/dsk/c1t1d2
/dev/dsk/c1t1d3
4. ....wait....until....mirrored....then...
5. # lvreduce -m 0 /dev/vg01/lv01 /dev/dsk/c1t1d1 /dev/dsk/c1t1d2
/dev/dsk/c1t1d3
6. Remove the original disks--> # vgreduce /dev/vg01 /dev/dsk/c4t1d1
/dev/dsk/c4t1d2 /dev/dsk/c4t1d3 /dev/dsk/c4t1d4
The real question is whether or not there truly is an issue when extending
VG's with larger volumes?
Thanks,
Sean C. Phillips
Professional Services - Implementation
EMC˛
where information lives
Cell & Pager: 734-223-1003
Mail: phillips_sean@emc.com <mailto:phillips_sean@emc.com>
AIM: tinfoilsuit
--
---> Please post QUESTIONS and SUMMARIES only!! <---
To subscribe/unsubscribe to this list, contact majordomo@dutchworks.nl
Name: hpux-admin@dutchworks.nl Owner: owner-hpux-admin@dutchworks.nl
Archives: ftp.dutchworks.nl:/pub/digests/hpux-admin (FTP, browse only)
http://www.dutchworks.nl/htbin/hpsysadmin (Web, browse & search)
This archive was generated by hypermail 2.1.7 : Sat Apr 12 2008 - 11:02:47 EDT