Re: Apparent strange disk behaviour in 6.0

Poul-Henning Kamp wrote:
> In message <42EB5687.2070400_at_elischer.org>, Julian Elischer writes:
> 
>>Poul-Henning Kamp wrote:
>>
>>>In message <42E88135.30603_at_elischer.org>, Julian Elischer writes:
>>>
>>>Please use gstat and look at the service times instead of the 
>>>busy percentage.
>>
>>The snapshot below is typical when doing tar from one drive to another..
>>(tar c -C /disk1 f- .|tar x -C /disk2 -f - )
>>
>>dT: 1.052  flag_I 1000000us  sizeof 240  i -1
>> L(q)  ops/s    r/s   kBps   ms/r    w/s   kBps   ms/w    d/s   kBps   ms/d %busy Name
>>    0    405    405   1057    0.2      0      0    0.0      0      0    0.0 9.8  | ad0
>>    0    405    405   1057    0.3      0      0    0.0      0      0    0.0 11.0 | ad0s2
>>    0    866      3     46    0.4    863   8459    0.7      0      0    0.0 63.8 | da0
>>   25    866      3     46    0.5    863   8459    0.8      0      0    0.0 66.1 | da0s1
>>    0    405    405   1057    0.3      0      0    0.0      0      0    0.0 12.1 | ad0s2f
>>  195    866      3     46    0.5    863   8459    0.8      0      0    0.0 68.1 | da0s1d
>>
>>even though the process should be disk limitted neither of the disks is anywhere
>>near 100%.
> 
> 
> This looks like an awful lot of small files since you write 8 times as much data
> as you read ?
> 
> Since the write service time (ms/w) is low, I pressume you have
> some hefty disk hardware (with cache ?)
> 
> Presumably you're using softupdates ?
> 
> I wouldn't be surprised if you were limited by system time rather than disk in
> this scenario ?

system is 87% idle

>