From: "Keld Jørn Simonsen" <keld@dkuug.dk>
To: linux-raid@vger.kernel.org
Subject: strange performance of raid0
Date: Sun, 15 Feb 2004 11:04:32 +0100 [thread overview]
Message-ID: <20040215100432.GA19002@rap.rap.dk> (raw)
Hi
I have some strange performance results on a raid0
I have 4 IDE disks on two controllers, the one on the
motherboard of the duron 1 GHz mackine, the other a promise TX2 plus
SATA + PATA controller. I run kernel 2.4.22
The disks and hdparm -t on each of them
/dev/hdc1 seagate 80 GB 16 MB/s
/dev/sda1 maxtor sata 200 GB 50 MB/s
/dev/sdb7 maxtor 160 GB 54 MB/s
The partitions are al about 5 GB each.
If I make a raid0 device of all of them I get a thruput of 45 MB/s
IIf I exclude the hdc1 partition, I get around 75 MB/s.
The system is a little loaded - but that would be normal operating
conditions. CPU is 90 % idle. I have about 100 MB free RAM.
Why is it slower with 3 disks in the raid0 than
2 disks? Why don't I get approx 100 MB/s out of just the two?
Best regards
Keld
next reply other threads:[~2004-02-15 10:04 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-02-15 10:04 Keld Jørn Simonsen [this message]
2004-02-15 9:54 ` strange performance of raid0 Matt Thrailkill
2004-02-15 12:05 ` Keld Jørn Simonsen
2004-02-15 11:55 ` Matt Thrailkill
2004-02-15 16:48 ` Keld Jørn Simonsen
2004-02-15 20:35 ` Mark Hahn
2004-02-15 20:49 ` Keld Jørn Simonsen
2004-02-15 23:58 ` Keld Jørn Simonsen
2004-02-17 17:50 ` Gregory Leblanc
2004-02-17 23:26 ` Keld Jørn Simonsen
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