weird iostat behaviour 1

[SeSe]

Hi,
Can anybody explain this:

# iostat -x
extended device statistics
device r/s w/s kr/s kw/s wait actv svc_t %w %b
md1 0.0 0.0 0.0 0.1 0.0 0.0 23.2 0 0
md2 0.0 0.0 0.2 0.0 0.0 0.0 54.0 0 0
md3 0.1 1.3 0.6 10.3 0.0 0.0 23.2 0 1
sd0 0.2 1.6 1.3 12.5 0.0 0.0 26.3 0 1
sd1 0.0 0.0 0.0 0.0 0.0 0.0 222.4 0 0
# iostat -M
tty md1 md2 md3 sd0 cpu
tin tout Mps tps serv Mps tps serv Mps tps serv Mps tps serv us sy wt id
0 7 0 0 23 0 0 54 0 1 23 0 2 26 2 1 1 96

As you see, sd1 does not appear in iostat -M but does in iostat -x (and that's a hole hard drive). It seems that this happens as well with systems with lots of metadevices (some of those show in iostat -x but not in iostat -M).
Thanks for your time,
Sorin

 

[Annihilannic]

Yep, 'cause iostat thinks you want to keep the output to 80 columns or so. You can specify the disks you want it to display to force it to include them, e.g. iostat -M md1 md2 md3 sd0 sd1. Annihilannic.

 

[SeSe]

Thanks - you're right. I will test it now for a machine with 50 md's to see how is it coping with that....