Date: Tue, 10 Sep 2002 18:37:31 -0500 From: "Jack L. Stone" <jackstone@sage-one.net> To: freebsd-questions@freebsd.org Subject: DD copy is too slow Message-ID: <3.0.5.32.20020910183731.00fbeac8@mail.sage-one.net>
next in thread | raw e-mail | index | archive | help
Am running FBSD 4.5-RELEASE
On one of the servers, am having very slow real dd copy speed vs test and
don't know why. Below is the test first made that shows 25MB/s but the real
dd copy is only doing about half the speed. Other servers are matching the
test. Wonder what is wrong with this machine I/O....??
DD TEST ONLY
dd if=/dev/ad0c of=/dev/null bs=128k
sageame@sagec$ iostat ad0 1
tty ad0 cpu
tin tout KB/t tps MB/s us ni sy in id
18 4 0.00 0 0.00 0 0 0 0100
88 58 128.00 200 25.06 0 0 2 0 98
20 48 128.00 200 25.01 0 0 2 0 98
0 44 128.00 200 25.00 0 0 1 1 98
0 44 123.32 203 24.45 0 0 1 1 98
0 44 128.00 187 23.39 0 0 1 0 99
0 44 128.00 189 23.65 0 0 0 0100
74 57 128.00 191 23.89 0 0 3 1 96
34 50 128.00 192 24.01 0 0 1 3 96
DD REAL COPY
dd if=/dev/ad0 of=/dev/ad1 bs=128k
sageame@sagec$ iostat ad0 1
tty ad0 cpu
tin tout KB/t tps MB/s us ni sy in id
18 4 0.00 0 0.00 0 0 0 0100
48 50 128.00 88 10.99 0 0 0 0100
0 44 128.00 88 11.02 0 0 1 0 99
0 44 128.00 87 10.89 0 0 1 0 99
0 44 128.00 88 11.02 0 0 1 0 99
0 44 128.00 87 10.89 0 0 0 0100
48 53 128.00 88 11.02 0 0 0 0100
60 53 128.00 88 11.02 0 0 1 0 99
Best regards,
Jack L. Stone,
Administrator
SageOne Net
http://www.sage-one.net
jackstone@sage-one.net
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3.0.5.32.20020910183731.00fbeac8>