mem@zinn.MV.COM (Mark E. Mallett) (01/16/89)
I'm having the dangdest time using floppies on my Microport Sys V/AT
system (v 2.4). When I first installed the thing, v 2.2, I did floppy
backups frequently without incident. Now, I'll format a floppy
(/etc/format /dev/rdsk/fd096), and 9 times out of 10, I'll get write
errors trying to use it. Subsequent attempts to write to the disk
(without reformatting) fail in the same place. If I am persistent, I
can repeat a cycle of formatting and attempting to use the disk, and
eventually it will work. (I have no such problems when I boot MS/DOS
and format/access disks.) Needless to say, this makes multi-disk
backups very difficult.
Before I try scrounging another drive, can someone tell me if I am
running into a known Microport problem?
-mm-
--
Mark E. Mallett Zinn Computer Co/ PO Box 4188/ Manchester NH/ 03103
Bus. Phone: 603 645 5069 Home: 603 424 8129 BIX: mmallett
uucp: mem@zinn.MV.COM ( ...{decvax|elrond|harvard}!zinn!mem )
Northern MA and Southern NH consultants: Ask me about MV.COMmike@cimcor.mn.org (Michael Grenier) (01/18/89)
From article <435@zinn.MV.COM>, by mem@zinn.MV.COM (Mark E. Mallett): > I'm having the dangdest time using floppies on my Microport Sys V/AT > system (v 2.4). When I first installed the thing, v 2.2, I did floppy > backups frequently without incident. Now, I'll format a floppy > (/etc/format /dev/rdsk/fd096), and 9 times out of 10, I'll get write > errors trying to use it. Subsequent attempts to write to the disk I had the same problem (though not 9 out 10 times) making multivolume backups nearly impossible. One possible problem seems to be doing the formatting when lot of other things are going on like serial interrupts. Anyway, I grew tired of the problem and wrote a floppy handler which works off the end of a pipe, .i.e ls|cpio -ocv|dbundle /dev/rdsk/fd ... The code is based on W. Davidson's posting of bundle/unbundle which breaks up the standard input across multiple volumes but my version will read after write on every track and retry if it failed. It also formats the floppy automatically should it run into unrecoverable errors and prompt for new diskettes at the end of each volume or to replace a diskette that's being difficult. It can be used with cpio , tar, or most anything. If there is enough requests, I'll post otherwise by email. -Mike Grenier mike@cimcor.mn.org
raw@ushiva.UUCP (Roland Wilcher) (01/18/89)
In article <639@cimcor.mn.org> mike@cimcor.mn.org (Michael Grenier) writes: >I had the same problem (though not 9 out 10 times) making multivolume >backups nearly impossible. One possible problem seems to be doing the >formatting when lot of other things are going on like serial interrupts. > >Anyway, I grew tired of the problem and wrote a floppy handler which >works off the end of a pipe, .i.e ls|cpio -ocv|dbundle /dev/rdsk/fd ... I also have this problem. Every time I have had this problem, when i reformat the disk using ms-dos, the dos format program always reports a few K in bad sectors. In order to do backups I have had to format the disks under ms-dos and only use those with no bad sectors. Looks like the uport stuff can't deal with bad sectors on the floppy. Also appears that the uport format program does not detect the bad sectors either. comments ? --- Every absurdity has a champion to defend it. raw@neologic%hal.crwu.edu {hal,decvax}!ncoast!ushiva!raw Roland A. Wilcher ------------------------------------------------------------------------------
learn@igloo.UUCP (william vajk) (01/18/89)
In article <43@ushiva.UUCP>, raw@ushiva.UUCP (Roland Wilcher) writes: > Looks like the uport stuff can't deal with bad sectors on the floppy. > Also appears that the uport format program does not detect the bad > sectors either. > comments ? If one follows the instructions included with runtime, one does a format, a labelit, and an mkfs. None of these added features are needed to make a cpio backup, and result in a LOT of wasted time. Running the other two does, somewhere in the sequence (I can't recall where cause I stopped doing it) identify a read or write error. Hell, they could have at least included a bell. On the other hand, they could have done it right. Bill Vajk | A person of quality is never intimidated. learn@igloo |
ken@uport.UUCP (Ken Chapin) (01/19/89)
In article <43@ushiva.UUCP> raw@ushiva.UUCP (Roland Wilcher) writes: >I also have this problem. Every time I have had this problem, when i >reformat the disk using ms-dos, the dos format program always reports >a few K in bad sectors. In order to do backups I have had to format >the disks under ms-dos and only use those with no bad sectors. >Looks like the uport stuff can't deal with bad sectors on the floppy. >Also appears that the uport format program does not detect the bad >sectors either. >comments ? > A disk is no good if it has surface flaws in it. Also the format code does not report errors (except for ocassional write errors) or try to do any mapping scheme with bad sectors. Ken Chapin UUCP: ...!{sun | ucbvax | ihnp4}!amdcad!uport!ken Microport Systems Technical Support
nvk@ddsw1.MCS.COM (Norman Kohn) (01/22/89)
In article <1419@igloo.UUCP> learn@igloo.UUCP (william vajk) writes: >In article <43@ushiva.UUCP>, raw@ushiva.UUCP (Roland Wilcher) writes: > >> Looks like the uport stuff can't deal with bad sectors on the floppy. >> Also appears that the uport format program does not detect the bad >> sectors either. >> comments ? > >If one follows the instructions included with runtime, one does a >format, a labelit, and an mkfs. None of these added features are >needed to make a cpio backup, and result in a LOT of wasted time. > Format will do just that; labelit won't look for bad sectors either. The best simple way to scan for bad sectores is to use dd to copy the volume to /dev/null. That way you don't even need to put a filesystem on it. Don't forget the bug (at least in uport 286) that causes silent errors in the first format after boot. If you reboot often, try reformatting the disk rather then assuming it's bad. If you seem to have a lot of bad floppies, suspect your floppy drive. For some reason some drives don't work happily with uport, and a simple drive swap may make quite a difference. (I've had to do it more than once.) -- Norman Kohn (...ddsw1!nvk!norman) eves: 373-0564 days/ans svc: 650-6840
mem@zinn.MV.COM (Mark E. Mallett) (01/22/89)
In article <43@ushiva.UUCP> raw@ushiva.UUCP (Roland Wilcher) writes: %In article <639@cimcor.mn.org> mike@cimcor.mn.org (Michael Grenier) writes: % %%I had the same problem (though not 9 out 10 times) making multivolume %%backups nearly impossible. % %I also have this problem. Every time I have had this problem, when i %reformat the disk using ms-dos, the dos format program always reports %a few K in bad sectors. In order to do backups I have had to format %the disks under ms-dos and only use those with no bad sectors. %Looks like the uport stuff can't deal with bad sectors on the floppy. %Also appears that the uport format program does not detect the bad %sectors either. %comments ? Are you suggesting that the Microport floppy problem is with bad sectors? Bad sectors on floppies are extremely rare. I expect that when I find a floppy with a bad sector, I need to find another floppy. Problems with floppies on my SYS V/AT system are extremely common. Even so, I specifically stated in my original posting (the reference to which seems to have gotten lost here :-) ) that I could format and use the floppies under MSDOS. So that's not it, I'm afraid. -mm- -- Mark E. Mallett Zinn Computer Co/ PO Box 4188/ Manchester NH/ 03103 Bus. Phone: 603 645 5069 Home: 603 424 8129 BIX: mmallett uucp: mem@zinn.MV.COM ( ...{decvax|elrond|harvard}!zinn!mem ) Northern MA and Southern NH consultants: Ask me about MV.COM
wnp@dcs.UUCP (Wolf N. Paul) (01/22/89)
In article <439@zinn.MV.COM> mem@zinn.MV.COM (Mark E. Mallett) writes: >Are you suggesting that the Microport floppy problem is with bad >sectors? Bad sectors on floppies are extremely rare. I expect that >when I find a floppy with a bad sector, I need to find another >floppy. Problems with floppies on my SYS V/AT system are extremely >common. Even so, I specifically stated in my original posting (the >reference to which seems to have gotten lost here :-) ) that I could >format and use the floppies under MSDOS. So that's not it, I'm afraid. That could still be it -- DOS will let you use floppies with bad sectors, it simply marks them as unavailable in the FAT. If you get a floppy with bad sectors, and format it under DOS, the format program will report, XXXXXXX bytes total XXXX bytes in bad sectors XXXXXXX bytes available whereas Uport's format program is a low-level formatting program, which neither verifies the formatted floppy, nor records bad sector information (how should it, since it doesn't know anything about a FAT, or a freelist. Any bad sector handling would need to be built into MKFS, not format; it may require changes to kernel file system code as well - don't know. and floppies with bad sectors ARE unusable for things like tar or cpio which look at the floppy as a stream of sectors -- can't have gaps in that. The other alternative is to write a floppy archiver, which verifies each floppy before writing to it, and keeps its own bad sector info somewhere at the beginning of the floppy. It can then be made intelligent enough to skip these bad sectors when reading or writing. -- Wolf N. Paul * 3387 Sam Rayburn Run * Carrollton TX 75007 * (214) 306-9101 UUCP: killer!dcs!wnp ESL: 62832882 DOMAIN: dcs!wnp@killer.dallas.tx.us TLX: 910-380-0585 EES PLANO UD
raw@ushiva.UUCP (Roland Wilcher) (01/23/89)
In article <439@zinn.MV.COM> mem@zinn.MV.COM (Mark E. Mallett) writes: > >Are you suggesting that the Microport floppy problem is with bad >sectors? Bad sectors on floppies are extremely rare. I expect that >when I find a floppy with a bad sector, I need to find another >floppy. Problems with floppies on my SYS V/AT system are extremely >common. Even so, I specifically stated in my original posting (the >reference to which seems to have gotten lost here :-) ) that I could >format and use the floppies under MSDOS. So that's not it, I'm afraid. > I beg to differ. I too can reformat the floppies and use them under dos. But dos marks bad sectors in the File allocation table on the floppy Unix format has no equivalant mechanism. I have these problems on V/386 3.0e so it's not limited it seems to V/AT. I also had this same foolishness on an AT&T 6386 running their System V 3.1 . --- Every absurdity has a champion to defend it. raw@neologic%hal.crwu.edu {hal,decvax}!ncoast!ushiva!raw Roland A. Wilcher ------------------------------------------------------------------------------
mem@zinn.MV.COM (Mark E. Mallett) (01/25/89)
In article <45@ushiva.UUCP> raw@ushiva.UUCP (Roland Wilcher) writes: >In article <439@zinn.MV.COM> mem@zinn.MV.COM (Mark E. Mallett) writes: >>Even so, I specifically stated in my original posting (the >>reference to which seems to have gotten lost here :-) ) that I could >>format and use the floppies under MSDOS. So that's not it, I'm afraid. >> >I beg to differ. I too can reformat the floppies and use them under dos. >But dos marks bad sectors in the File allocation table on the floppy >Unix format has no equivalant mechanism. You are, of course, correct. (Having written code to implement MSDOS filesystems, you'd think I'd have taken that into consideration.) But I stand by the point that I was attempting to make, even if I did it badly: bad sectors in floppies are very rare. I'd be very very surprised if every single floppy disk that I have has bad spots, yet that's what I'm told by trying to use them on my system. And note that reformatting them changes the location and sometimes the existence of the bad sectors, which I also mentioned. This is not the behaviour of a bad disk; it is the behaviour of a bad disk drive, interface, or software. I use a number of different Unix systems often; my System V/AT system is the only one with this trouble. What I really wanted to know is whether other people were having the same troubles, whether I should try buying another drive. Enough people have responded by saying their System V/AT systems behave the same way, that I'm inclined to believe it is indeed software. Software people (me included) are always quick to blame the hardware (or anything physical). Here, though, I think it's reasonable to question the software. -mm- -- Mark E. Mallett Zinn Computer Co/ PO Box 4188/ Manchester NH/ 03103 Bus. Phone: 603 645 5069 Home: 603 424 8129 BIX: mmallett uucp: mem@zinn.MV.COM ( ...{decvax|elrond|harvard}!zinn!mem ) Northern MA and Southern NH consultants: Ask me about MV.COM
brian@cbw1.UUCP (Brian Cuthie) (01/27/89)
In article <307@dcs.UUCP> wnp@dcs.UUCP (Wolf N. Paul) writes: >... DOS will let you use floppies with bad sectors, >it simply marks them as unavailable in the FAT. If you get a floppy with >bad sectors, and format it under DOS, the format program will report, > > > XXXXXXX bytes total > XXXX bytes in bad sectors > XXXXXXX bytes available > >whereas Uport's format program is a low-level formatting program, which neither >verifies the formatted floppy, nor records bad sector information (how should >it, since it doesn't know anything about a FAT, or a freelist. Actually, there is a way for the uport driver and format routine to handle bad sectors on floppies. Instead of having 15 usable sectors per track, you only use 14. This leaves one sector per track for alternate mapping. The disk controller (be it floppy or hard disk) does not care what order the sectors are in. Thus assume sectors were normally ordered (use 1:1 interleave for simplicity) 1 2 3 4 5 6* 7 8 9 10 11 12 13 14 XX. If sector 6 were bad, then it could be remapped by the format program so that the track was formated in this order: 1 2 3 4 5 XX 7 8 9 10 11 12 13 14 6. The controller would never know the difference, since it always searches for the proper header id before reading/writing a sector. -brian -- Brian D. Cuthie uunet!umbc3!cbw1!brian Columbia, MD brian@umbc3.umbc.edu
wnp@dcs.UUCP (Wolf N. Paul) (01/27/89)
In article <136@cbw1.UUCP> brian@cbw1.UMD.EDU (Brian Cuthie) writes: >Actually, there is a way for the uport driver and format routine to handle >bad sectors on floppies. Instead of having 15 usable sectors per track, you >only use 14. This leaves one sector per track for alternate mapping. But then people would complain about losing 80 KB per floppy, even if there are no bad sectors on it. I recently swapped my floppy with one I had in a DOS-only machine, and most of my floppy problems went away. The drive which was giving me trouble under UNIX works just fine under DOS, where timing is not as crucial. -- Wolf N. Paul * 3387 Sam Rayburn Run * Carrollton TX 75007 * (214) 306-9101 UUCP: killer!dcs!wnp ESL: 62832882 DOMAIN: dcs!wnp@killer.dallas.tx.us TLX: 910-380-0585 EES PLANO UD