From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 6 Oct 2005 23:51:25 -0400 From: "Thomas Miller" To: 9fans@cse.psu.edu Subject: Re: [9fans] fossil shutdown Message-ID: <4345f0bd.l5R330s/pBsD2tR1%tom@insolvencyhelp.org> References: <773c9e03fdb75bc23d88836c96abb42a@terzarima.net> In-Reply-To: <773c9e03fdb75bc23d88836c96abb42a@terzarima.net> User-Agent: nail 11.19 1/2/05 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Topicbox-Message-UUID: 9569ae42-ead0-11e9-9d60-3106f5b1d025 Way back on September 22, 2005 Charles Forsyth wrote: > > perhaps you need > > echo dma on >/dev/sdXX/ctl > echo rwm on >/dev/sdXX/ctl > Inspired, I tried this, and I got an improvement (decrease) in time taken to copy files to a new filename of at least an order of magnitude. The really interesting part of the experiment was, however, that my computer subsequently failed to boot from the hard disk. I guessed from the boot messages that 9LOAD was not starting, and maybe the partition 0 bootloader wasn't starting. So I booted from the install cd and took a look at the beginning of the disk with cat /dev/sdC0/data | sed 10q I was surprised to find the letters "rwm on" right at the beginning of the disk. I saved the output of cat /dev/sdC0/data | sed 10q > cat0.out at ftp.insolvencyhelp.org/pub/cat0.out if anybody wants to see. I decided to reinstall the partition 0 bootloader with disk/mbr -m /386/mbr /dev/sdC0/data after which the machine now seems to boot just fine, and all the files seem okay too. For comparison, I saved the beginning of the disk as it was *subsequent* to reinstalling the partition 0 bootloader as cat1.out at the previously mentioned ftp location. I mention all this to 9fans because I wonder whether somebody can tell me, possibly from looking at the other differences between the two disk images beyond just the "rwm on," what I did wrong. I'm pretty sure that I did *not* type echo rwm on > /dev/sdC0/data /* WRONG */ if that would cause the problem. I have not tried to reproduce the problem, but I could try if people want me to do that. The machine on which this occurred is an x86, and the disk is an IDE. It's still running kfs. It certainly is nice to have multiple backups! :-) It certainly is nice to have Plan 9. Thank you to Bell Labs and 9fans. Kindest regards, Tom Miller