Mirror parallel policy reads from primary disk?!

[Morsing]

I've noticed on a 5.1 server that although the sched policy is set to parallel, it always reads from the primary disk (without exception). Even when running a heavy batch process (lots of I/O) it stays on the primary disk.

The box has two different VG, both mirrored, both with parallel policy and it does it on both mirrors.
I haven't looked at other machines yet.

Is it a bug or have I missed something??

Cheers Henrik Morsing
Certified AIX 4.3 Systems Administration
& p690 Technical Support

 

[Morsing]

Aahhh... I just figured it out!!

I had been sent a nmon excel sheet by someone and it showed the read activity as being average 2MB/s over two hours on both VG's but only on the primary disks.

I hadn't noticed that it only showed the *weighted* average because the real average was close to zero. The two MB/s was only one burst.

Sorry about that.

Cheers
Henrik Morsing
Certified AIX 4.3 Systems Administration
& p690 Technical Support