LVM and VxVM

pvmove on mounted production server

 
meem_1
New Member

pvmove on mounted production server

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
4 REPLIES 4
Bill Hassell
Honored Contributor

Re: pvmove on mounted production server

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.


Bill Hassell, sysadmin
AwadheshPandey
Honored Contributor

Re: pvmove on mounted production server

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
It's kind of fun to do the impossible
Ismail Azad
Esteemed Contributor

Re: pvmove on mounted production server

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
Read, read and read... Then read again until you read "between the lines".....
BDD
Advisor

Re: pvmove on mounted production server

Hi

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

BDD