Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!ucselx!crash!pnet01!cwr From: cwr@pnet01.cts.com (Will Rose) Newsgroups: comp.os.minix Subject: PC Minix and 1.44MB floppies Message-ID: <3851@crash.cts.com> Date: 8 Aug 90 02:16:04 GMT Sender: root@crash.cts.com Organization: People-Net [pnet01], El Cajon CA Lines: 39 I recently had to copy some Minix filesystems on 1.44MB disks on an XT with one 360KB and one 1.44MB floppy. MSDOS 3.3 diskcopy works for 360KB disks, but I found that 'diskcopy b: b:' attempted to reformat the target disk to 15 sectors/track, ie. the spt for a 1.2 MB device. This despite the fact that the disk was already formatted to 18 spt. I can't believe diskcopy had kept bugs so long, but so it seems. This may be the problem reported by those trying to move Minix to 3.5 disks of any size - I don't have a 720 KB disk to test with diskcopy. My next shot was to use dd under Minix (I wanted to keep file time and date stamps intact, and move seemed a bit risky). This worked, but the copying took a long time. I tried a couple of different block sizes, 512B (the default) and 1KB, and read the floppy device into a file on a hard disk; curiously, one blocksize was slower reading onto the hard disk and the other was slower reading onto the floppy. The times were: dd if=/dev/fd1 of=file bs=1k count=1440 takes 15 min. dd if=file of=/dev/fd1 bs=1k count=1440 takes 7 min. dd if=/dev/fd1 of=file count=2880 takes 6 min. dd if=file of=/dev/fd1 count=2880 takes 12 min. Are these times typical, and is there any input buffering or whatever that could speed things up? I'm using a 'safe' filesystem, with blocks written out to the disk immediately rather than buffered on the output; but the performance still seems awfully slow. The machine is a 10MHz XT running (very) standard 1.5.10. All suggestions gratefully received - Will ----------------------------------------------------------------------- "If heaven too had passions | Will Rose even heaven would | UUCP: {nosc ucsd hplabs!hp-sdd}!crash!pnet01!cw grow old." - Li Ho. | ARPA: crash!pnet01!cwr@nosc.mil | INET: cwr@pnet01.cts.com UUCP: {nosc ucsd hplabs!hp-sdd}!crash!pnet01!cwr ARPA: crash!pnet01!cwr@nosc.mil INET: cwr@pnet01.cts.com