topic Re: pvmove on mounted production server in Operating System - HP-UX

pvmove on mounted production server

meem_1 — Thu, 19 May 2011 07:49:48 GMT

Hi,

is it safe to do pvmove on mounted production server?

I'd like to remove PV from VG, after shrinking the FS as the utilization is low.

it's hp-ux 11.11

thank you

Re: pvmove on mounted production server

Bill Hassell — Thu, 19 May 2011 12:45:16 GMT

pvmove will move the extents very carefully, checking the validity, then copying it, verifying the copy and then changing the extent map to point to the new location. AS such, it is very slow so any activity on that VG will be delayed until all the extents are moved. It should be safe on a production server, but like any data transfer, a hang or core dump or system crash could leave the VG damaged, possibly requiring a complete rebuild and restore.

Re: pvmove on mounted production server

AwadheshPandey — Fri, 20 May 2011 13:28:24 GMT

hello meem,

better you post vgdisplay -v o/p for vg.
then tellme what you want.
pvmove is safe but must be used carefully.

Regards,

Awadhesh

Re: pvmove on mounted production server

Ismail Azad — Sat, 21 May 2011 20:12:50 GMT

Hi meem,

What you are trying to do is standard procedure. Moving extents off a disk that is underutilized and making it usable on a more appropriate volume group.

Just one word of caution, careless pvmove's, lvextend's etc can lead to the fragmentation of the extent space on LVM which is a prominent concept on the line of Monitoring Performance on LVM. And the obvious tool would be something like a generic unix tool like sar or let's say a more known form on HPUX called as glance.

Regards
Ismail Azad

Re: pvmove on mounted production server

BDD — Thu, 09 Jun 2011 11:01:04 GMT

Hi

Its possible but if your server is having heavy IO this PV move will creating performance issue .

BDD