Date: Sun, 19 Apr 1998 22:31:37 -0700 From: Mike Smith <mike@smith.net.au> To: Berend de Boer <berend@pobox.com> Cc: "'Mike Smith'" <mike@smith.net.au>, "stable@FreeBSD.ORG" <stable@FreeBSD.ORG> Subject: Re: best sd0 flags ? (was wdc0) Message-ID: <199804200531.WAA04185@antipodes.cdrom.com> In-Reply-To: Your message of "Sat, 18 Apr 1998 21:11:14 %2B0200." <01BD6B0E.863498B0.berend@pobox.com>
next in thread | previous in thread | raw e-mail | index | archive | help
> On Saturday, April 18, 1998 6:46 PM, Mike Smith [SMTP:mike@smith.net.au] > wrote: > > > > We've been duplicating 3GB Western Digital disks the last few days under > > 2.2.6, flags 0x80ff80ff on 166MHz P5/430TX boards, and averaging about > > 5M/sec throughput. Try 'dd if=/dev/wd1 of=/dev/null bs=1m' to get an > > idea of your raw disk speed as opposed to filesystem throughput. > > Hmm, something is seriously wrong here it seems. I've a Pentium II, 233MHz, > 128MB, Adaptec Ultra Wide SCSI and SCSI 2 4GB IBM drive. Using the above > code I get an average of 2MB. Is there something seriously wrong with this > system? And how can I tune it? As Bruce mentioned, you should use the raw device: azaria# dd if=/dev/sd1 of=/dev/null bs=1m count=20 20+0 records in 20+0 records out 20971520 bytes transferred in 9.182458 secs (2283868 bytes/sec) azaria# dd if=/dev/rsd1 of=/dev/null bs=1m count=20 20+0 records in 20+0 records out 20971520 bytes transferred in 2.571084 secs (8156684 bytes/sec) for a similar configuration (DCAS34330UW, PII/337, AHA2940UW) -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199804200531.WAA04185>