queue_depth change on fly?

[ogniemi]

I guess it is not possible until the vg is varied off (or by unmirroring/reducevg/chdev/mirroring vg's disks one by one).

in:

http://publib.boulder.ibm.com/infoc...x.prftungd/doc/prftungd/disk_disk_adapter.htm

there is:

Change: chdev -l hdiskn -a q_type=simple -a queue_depth=NewValueChange is effective immediately and is permanent. If the -T flag is used, the change is immediate and lasts until the next boot. If the -P flag is used, the change is deferred until the next boot and is permanent.

I am curious about "is effective immediately"...

 

[p5wizard]

The chdev ... command will fail if the disk is in use. If the disk is not in use at the time of issuing the chdev command, the change is immediate and permanent.

chdev ... -T (temporary - change until next boot)
chdev ... -P (deffered - change at next boot)

HTH,

p5wizard