slow RAID-5 on FreeBSD 5.4

[Tamouh H.]

On another note, I've ran diskinfo test and these are the results, much better but still the RAID-5 slower than a single drive:

impala# diskinfo -t aacd1
aacd1
        512             # sectorsize
        146781044736    # mediasize in bytes (137G)
        286681728       # mediasize in sectors
        17845           # Cylinders according to firmware.
        255             # Heads according to firmware.
        63              # Sectors according to firmware.

Seek times:
        Full stroke:      250 iter in   3.291258 sec =   13.165 msec
        Half stroke:      250 iter in   2.362839 sec =    9.451 msec
        Quarter stroke:   500 iter in   3.908358 sec =    7.817 msec
        Short forward:    400 iter in   2.478195 sec =    6.195 msec
        Short backward:   400 iter in   2.459182 sec =    6.148 msec
        Seq outer:       2048 iter in   0.661217 sec =    0.323 msec
        Seq inner:       2048 iter in   0.637923 sec =    0.311 msec
Transfer rates:
        outside:       102400 kbytes in   1.659174 sec =    61717 kbytes/sec
        middle:        102400 kbytes in   1.763043 sec =    58081 kbytes/sec
        inside:        102400 kbytes in   2.867523 sec =    35710 kbytes/sec

impala# diskinfo -t aacd0
aacd0
        512             # sectorsize
        293561434112    # mediasize in bytes (273G)
        573362176       # mediasize in sectors
        35690           # Cylinders according to firmware.
        255             # Heads according to firmware.
        63              # Sectors according to firmware.

Seek times:
        Full stroke:      250 iter in   2.966840 sec =   11.867 msec
        Half stroke:      250 iter in   2.270758 sec =    9.083 msec
        Quarter stroke:   500 iter in   4.493850 sec =    8.988 msec
        Short forward:    400 iter in   2.681128 sec =    6.703 msec
        Short backward:   400 iter in   1.520458 sec =    3.801 msec
        Seq outer:       2048 iter in   0.631963 sec =    0.309 msec
        Seq inner:       2048 iter in   0.625584 sec =    0.305 msec
Transfer rates:
        outside:       102400 kbytes in   2.139737 sec =    47856 kbytes/sec
        middle:        102400 kbytes in   3.080063 sec =    33246 kbytes/sec
        inside:        102400 kbytes in   4.358889 sec =    23492 kbytes/sec
 
> 
> Hello,
> 
> I've just ran Bonnie on a FreeBSD 5.4 machine with Adaptec 
> 2230SLP RAID-5 SCSI Card and Seagate 146GB 10K RPM U320 drives. 
> 
> The results were very surprising. The RAID-5 is EXTREMELY 
> slow, and I can't figure out why! 
> 
> The RAID controller has two volumes: RAID-5 and a lone drive.
> 
> This is Bonnie results from the lone drive on the Adaptec card:
> 
> impala# ./Bonnie -d /tmp
> File '/tmp/Bonnie.30883', size: 104857600 Writing with 
> putc()...done Rewriting...done Writing intelligently...done 
> Reading with getc()...done Reading intelligently...done 
> Seeker 1...Seeker 2...Seeker 3...start 'em...done...done...done...
>               -------Sequential Output-------- ---Sequential 
> Input-- --Random--
>               -Per Char- --Block--- -Rewrite-- -Per Char- 
> --Block--- --Seeks---
> Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU 
> K/sec %CPU  /sec %CPU
>           100 27168 28.2 31668 13.9 36530 10.8 83540 92.1 
> 495217 98.5 26086.8 182.8
> 
> Here are the results doing the same test on the RAID-5:
> 
> impala# ./Bonnie -d /usr
> File '/usr/Bonnie.30972', size: 104857600 Writing with 
> putc()...done Rewriting...done Writing intelligently...done 
> Reading with getc()...done Reading intelligently...done 
> Seeker 1...Seeker 2...Seeker 3...start 'em...done...done...done...
>               -------Sequential Output-------- ---Sequential 
> Input-- --Random--
>               -Per Char- --Block--- -Rewrite-- -Per Char- 
> --Block--- --Seeks---
> Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU 
> K/sec %CPU  /sec %CPU
>           100  7478  7.7 10727  4.3  7250  3.2 101910 99.6 
> 1464070 99.2 24067.2 180.6