"why is my Linux so damn slow?"

[M. Fioretti]

On Sat, Feb 12, 2011 19:03:56 PM +0100, Marco Fioretti (mfioretti at nexaima.net) wrote:
> On Sat, Feb 12, 2011 12:55:16 PM -0500, Lamar Owen (lowen at pari.edu) wrote:
> > On Saturday, February 12, 2011 12:19:33 pm M. Fioretti wrote:
> > > besides hard drive and DVD burner there are only Logitech webcam,
> > > wheelmouse and earphone microphone, but everything is plugged in
> > > the back which is not really accessible without moving
> > > furniture. I'll do that if needed, but isn't a way to check for
> > > those interrupts from the prompt?
> >
> > Let's see if iowaits are you issue.  Install the sysstat package
> > (yum install sysstat) and run: iostat -x 1
> 
> 
> here it is, thanks for the tip. When it isn't zero, the await column
> gives anything from 27.36 to 35.78 (last line) to 5 (I have already
> posted top output in a comment to the web page):
> 
> [root at polaris ~]# iostat -x 1 | egrep -i 'device|sda'

Sorry, of course that's only the part of the story about sda. here is one complete run of iostat:


Device:         rrqm/s   wrqm/s     r/s     w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
sda               0.00     5.00    0.00    5.00     0.00    64.00    12.80     0.03    6.00   6.00   3.00
dm-0              0.00     0.00    0.00    8.00     0.00    64.00     8.00     0.04    4.38   3.75   3.00
dm-1              0.00     0.00    0.00    0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00

other runs show all null values for  dm-0 / dm-1, or values similar to these

Marco