busy disks - a lot of write activities on / part

[Bill Moran]

In response to Garrett Cooper <youshi10 at u.washington.edu>:

> On Jun 28, 2006, at 8:51 AM, Tamouh H. wrote:
> 
> >
> > I'm diagnosing a slow hard disk issues , trying to determine where  
> > the bottleneck in all of this. The system is FreeBSD 5.4 with SCSI  
> > U320 drives in RAID-5 on Adaptec 2130SLP Controller.
> >
> > I'm noticing the / boot partition has the most activities for  
> > writes/Busy and was wondering if anyone can shed some lights on  
> > this and what can possibly be done to speed up the drives.
> >
> > doing 'gstat' shows:
> >
> > dT: 0.510  flag_I 500000us  sizeof 240  i -1
> >  L(q)  ops/s    r/s   kBps   ms/r    w/s   kBps   ms/w   %busy Name
> >     0      0      0      0    0.0      0      0    0.0    0.0| acd0
> >     1    141      6    259    6.6    135   1466  121.0   94.3| aacd0
> >     0      0      0      0    0.0      0      0    0.0    0.0| aacd1
> >     0      0      0      0    0.0      0      0    0.0    0.0| acd0t01
> >     1    141      6    259    6.7    135   1466  121.0   94.5| aacd0s1
> >     0      0      0      0    0.0      0      0    0.0    0.0| aacd1s1
> >     1     61      0      0    0.0     61    549   16.6  101.2|  
> > aacd0s1a
> >     0      0      0      0    0.0      0      0    0.0    0.0|  
> > aacd0s1b
> >     0      0      0      0    0.0      0      0    0.0    0.0|  
> > aacd0s1c
> >     0     73      0      0    0.0     73    906  205.1   48.6|  
> > aacd0s1d
> >     0      4      2      4    7.9      2     12  242.6   49.1|  
> > aacd0s1e
> >     0      4      4    255    6.1      0      0    0.0    2.4|  
> > aacd0s1f
> >     0      0      0      0    0.0      0      0    0.0    0.0|  
> > aacd1s1c
> >     0      0      0      0    0.0      0      0    0.0    0.0|  
> > aacd1s1d
> >     0      0      0      0    0.0      0      0    0.0    0.0|  
> > aacd1s1e
> >
> > This is df:
> >
> > Filesystem     1K-blocks     Used     Avail Capacity  Mounted on
> > /dev/aacd0s1a     809998    59430    685770     8%    /
> > devfs                  1        1         0   100%    /dev
> > /dev/aacd1s1e    1722888    14892   1570166     1%    /tmp
> > /dev/aacd0s1f  209955742 62440662 130718622    32%    /home
> > /dev/aacd0s1d   35921132  6151076  26896366    19%    /usr
> > /dev/aacd0s1e   22270798  3480300  17008836    17%    /var
> > devfs                  1        1         0   100%    /var/named/dev
> > procfs                 4        4         0   100%    /proc
> > /dev/aacd1s1d  137099908 70149522  55982394    56%    /backup
> >
> > Any info on matter of disks performance is much appreciated.
> >
> > Thx,
> >
> > Tamouh Hakmi
> 
> Try compiling and installing lsof in ports. That may help in  
> determining what files are open so then you can trace the files back  
> to any given processes that may still have the files open, so then  
> you can determine the bottlenecks better.

lsof is nice, but don't forget about fstat, which comes with FreeBSD.

-- 
Bill Moran
Collaborative Fusion Inc.

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