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Date:      Sat, 21 Jan 2006 19:15:20 -0500
From:      "Tamouh H." <hakmi@rogers.com>
To:        <freebsd-questions@freebsd.org>
Subject:   RE: slow RAID-5 on FreeBSD 5.4
Message-ID:  <20060122001523.4E29243D5F@mx1.FreeBSD.org>
In-Reply-To: <20060122000609.3DDFE43D48@mx1.FreeBSD.org>

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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 =3D   13.165 msec
        Half stroke:      250 iter in   2.362839 sec =3D    9.451 msec
        Quarter stroke:   500 iter in   3.908358 sec =3D    7.817 msec
        Short forward:    400 iter in   2.478195 sec =3D    6.195 msec
        Short backward:   400 iter in   2.459182 sec =3D    6.148 msec
        Seq outer:       2048 iter in   0.661217 sec =3D    0.323 msec
        Seq inner:       2048 iter in   0.637923 sec =3D    0.311 msec
Transfer rates:
        outside:       102400 kbytes in   1.659174 sec =3D    61717 =
kbytes/sec
        middle:        102400 kbytes in   1.763043 sec =3D    58081 =
kbytes/sec
        inside:        102400 kbytes in   2.867523 sec =3D    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 =3D   11.867 msec
        Half stroke:      250 iter in   2.270758 sec =3D    9.083 msec
        Quarter stroke:   500 iter in   4.493850 sec =3D    8.988 msec
        Short forward:    400 iter in   2.681128 sec =3D    6.703 msec
        Short backward:   400 iter in   1.520458 sec =3D    3.801 msec
        Seq outer:       2048 iter in   0.631963 sec =3D    0.309 msec
        Seq inner:       2048 iter in   0.625584 sec =3D    0.305 msec
Transfer rates:
        outside:       102400 kbytes in   2.139737 sec =3D    47856 =
kbytes/sec
        middle:        102400 kbytes in   3.080063 sec =3D    33246 =
kbytes/sec
        inside:        102400 kbytes in   4.358889 sec =3D    23492 =
kbytes/sec
=20
>=20
> Hello,
>=20
> I've just ran Bonnie on a FreeBSD 5.4 machine with Adaptec=20
> 2230SLP RAID-5 SCSI Card and Seagate 146GB 10K RPM U320 drives.=20
>=20
> The results were very surprising. The RAID-5 is EXTREMELY=20
> slow, and I can't figure out why!=20
>=20
> The RAID controller has two volumes: RAID-5 and a lone drive.
>=20
> This is Bonnie results from the lone drive on the Adaptec card:
>=20
> impala# ./Bonnie -d /tmp
> File '/tmp/Bonnie.30883', size: 104857600 Writing with=20
> putc()...done Rewriting...done Writing intelligently...done=20
> Reading with getc()...done Reading intelligently...done=20
> Seeker 1...Seeker 2...Seeker 3...start 'em...done...done...done...
>               -------Sequential Output-------- ---Sequential=20
> Input-- --Random--
>               -Per Char- --Block--- -Rewrite-- -Per Char-=20
> --Block--- --Seeks---
> Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU=20
> K/sec %CPU  /sec %CPU
>           100 27168 28.2 31668 13.9 36530 10.8 83540 92.1=20
> 495217 98.5 26086.8 182.8
>=20
> Here are the results doing the same test on the RAID-5:
>=20
> impala# ./Bonnie -d /usr
> File '/usr/Bonnie.30972', size: 104857600 Writing with=20
> putc()...done Rewriting...done Writing intelligently...done=20
> Reading with getc()...done Reading intelligently...done=20
> Seeker 1...Seeker 2...Seeker 3...start 'em...done...done...done...
>               -------Sequential Output-------- ---Sequential=20
> Input-- --Random--
>               -Per Char- --Block--- -Rewrite-- -Per Char-=20
> --Block--- --Seeks---
> Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU=20
> K/sec %CPU  /sec %CPU
>           100  7478  7.7 10727  4.3  7250  3.2 101910 99.6=20
> 1464070 99.2 24067.2 180.6





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