busy disks - a lot of write activities on / part

[Garrett Cooper]

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.
-Garrett