Date: Sat, 21 Jan 2006 19:06:05 -0500 From: "Tamouh H." <hakmi@rogers.com> To: <freebsd-questions@freebsd.org> Subject: slow RAID-5 on FreeBSD 5.4 Message-ID: <20060122000609.3DDFE43D48@mx1.FreeBSD.org>
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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.=20
The results were very surprising. The RAID-5 is EXTREMELY slow, and I =
can't figure out why!=20
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
Notice the 7MB write speed compared to 30MB. The read speeds are still =
very slow considering these are SCSI drives (I've done another test on =
S-ATA drive and it had the same Read speed, but much slower write).
I believe the drives are working fine, I don't suspect problems with =
them. However, smartmontools doesn't support Adaptec RAID.
Anything suggested to imrpove the RAID-5 performance ? It is surprising =
both tests were ran against the same card.
Thanks,
Tamouh Hakmi
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