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Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!olivea!gossip.pyramid.com!pyramid!cbmvax!yoda!ford From: ford@yoda.omnicron.com (Mike "Ford" Ditto) Newsgroups: comp.os.386bsd.questions Subject: swap space troubles Keywords: installation disk partitions swap space Message-ID: <1028@yoda.omnicron.com> Date: 10 Jun 93 02:04:44 GMT Reply-To: ford@omnicron.com (Mike "Ford" Ditto) Organization: Omnicron Data Systems Lines: 96 Hi, I have painstakingly installed 386BSD 0.1 on a subnotebook machine without a floppy drive. I am experiencing some strange behavior which mostly relates to swap space. I did not find anything which sounded like an answer to my problem in the FAQ list or the recent postings here, so I am seeking advice from anyone who can understand these problems... I am running the kernel from the distribution floppies; I haven't installed the kernel source (and don't have enough RAM yet to do any significant compiling). My disklabel looks like this: # /dev/rwd0a: type: ESDI disk: IDE label: Z-LITE-HD-60 flags: bytes/sector: 512 sectors/track: 38 tracks/cylinder: 4 sectors/cylinder: 152 cylinders: 823 rpm: 3600 interleave: 1 trackskew: 0 cylinderskew: 0 headswitch: 0 # milliseconds track-to-track seek: 0 # milliseconds drivedata: 0 7 partitions: # size offset fstype [fsize bsize cpg] a: 15884 0 4.2BSD 512 4096 32 # (Cyl. 0 - 104*) b: 33440 15960 swap # (Cyl. 105 - 324) c: 15884 49400 4.2BSD 512 4096 32 # (Cyl. 325 - 429*) d: 125096 0 unused 0 0 # (Cyl. 0 - 822) e: 55936 65360 4.2BSD 512 4096 32 # (Cyl. 430 - 797) f: 3800 121296 4.2BSD 512 4096 32 # (Cyl. 798 - 822) g: 75696 49400 4.2BSD 512 4096 32 # (Cyl. 325 - 822) Problem #1: When the system panics, it dumps memory onto the beginning of the hard disk, wiping out everything. This means I have to download the whole distribution again over the serial port. Is there any way to disable this misfeature? Problem #2: Sometimes when the system boots, I get the message: Warning: no swap space (yet). What does this mean and why does it only appear sometimes? When this message appears, the system often does not come up all the way, hanging while "starting local daemons". Problem #3: I occationally see the message: wd0a: overlaps open partition (b) When I read the partition table using "disklabel /dev/wd0d" I see that the offset of partition B has been changed to zero and the size has been changed to 5776. "disklabel -r /dev/rwd0d" shows that the label on the disk is still OK, only the in-memory copy has been modified. This seems to be a result of some buggy code in isa/wd.c which mysteriously modifies the B partition in a most nonsensical way. (It sets the offset to zero and the size to the number of sectors per track squared times the number of heads!) The result of this seems to be that the system uses the beginning of the disk (the root filesystem) as a swap area! The system frequently panics with a corrupt inode 2, which immediately is made even more corrupt by Problem #1. The mysteries to me are why this code is there at all, and why it only sometimes causes this problem. When I cold boot from a power up everything seems fine, but a warm boot usually results in the bad partition table and/or the "no swap space" message. I have been running the system ok for some time now, but only by carefully observing these messages and rebooting when they appear. -=] Ford [=- "The number of Unix installations (In Real Life: Mike Ditto) has grown to 10, with more expected." ford@omnicron.com - The Unix Programmer's Manual, uunet!cbmvax!yoda!ford 2nd Edition, June, 1972.