[SunHELP] How to determine what causes a disk is busy

[Ben Ricker]

Top may help in this: correlate disk spikes with the process(es) taking
up the most kernel CPU time. Also, if you know that the processes DO,
you can make an educated guess. For instance, a database being run with
too little RAM may force too much disk IO, thereby forcing it to disk
cache.

You can get top from www.sunfreeware.com.

Ben Ricker
Wellinx.com

On Thu, 2003-07-10 at 16:42, Nguyen, David M wrote:
> I run iostat to check disk activity and suspect the disk is so busy by
> looking at column %b.  How do I find out what causes the disk busy?  I
> run Solaris8.  Thanks.
> 
> #iostat -x 1 10
>                   extended device statistics
> device       r/s    w/s   kr/s   kw/s wait actv  svc_t  %w  %b
> sd0         75.0   66.3 1731.2  520.4  0.1  4.1   29.6   0  92
> sd6          0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0
> nfs1         0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0
>                   extended device statistics
> device       r/s    w/s   kr/s   kw/s wait actv  svc_t  %w  %b
> sd0         50.6   67.4 4782.5  539.3  0.0  3.1   26.4   0 100
> sd6          0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0
> nfs1         0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0
>                   extended device statistics
> device       r/s    w/s   kr/s   kw/s wait actv  svc_t  %w  %b
> sd0         42.0   74.0 4064.1  592.0  0.0  3.6   31.2   0 100
> sd6          0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0
> nfs1         0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0
> _______________________________________________
> SunHELP maillist  -  SunHELP at sunhelp.org
> http://www.sunhelp.org/mailman/listinfo/sunhelp