Subject: questions about fs layout and veracity of dd timings
To: None <current-users@NetBSD.ORG>
From: jason baker <jabaker@grail.cba.csuohio.edu>
List: port-i386
Date: 03/16/1995 13:05:27
Hello,
I have an i386 with a fairly new 245 meg ide drive, and a full
height lxt-340 meg scsi. I am considering adding a full height
quantum 105 from my old atari. Right now, the ide drive holds dos and
/, while the 340 holds /usr and some swap space. My first thought
was to make the 105 /usr and the 340 /usr/src. (I figure that if
binaries are kept seperate from everything else, paging text segments
should be faster.)
Today, I hooked up the 105 and played around with dd. Running
dd ibs=65535 obs=65536 count=256 if=/dev/rxxxd of=/dev/null on either
the ide drive or the 340 will give 2097152 bytes/sec (my scsi
controller does pio), while on the 105 it complains about the lack of
a disklabel and gives 578524 bytes/sec. Is the lack of a disklabel
slowing down every read or is the 105 really that slow? I always
imagined that my big old drives where contemperaries and would have
similar performance.
If the 105 is that slow, perhaps I could use it for /usr/src
and divide the 340 between /usr and /usr/local with /usr/local/bin
symlinked to /usr/.local.bin. Or perhaps isolating pure text segments
is not as important as I think. In any case, I am curious: How big
is /usr/src on an i386 once everying has been built?
thanks for any and all woderful advice,
Jason