philip@dalcsug.UUCP (03/31/87)
In article <1580@cbmvax.cbmvax.cbm.UUCP> daveh@cbmvax.UUCP writes: >I know.... I'm working on it. Though, at least on occasion, the thing you're >trying to read is completely trashed, and nothing short of some serious >magick would help it. That's, of course, what backups are for. Yesterday I did what I have nightmares about ... I pulled a disk out while the drive light was on. Egad! Panic! thank god it was not irreplaceable, but I thought that I would just fix it with disksalv and everything would be wonderful. I was wrong. I reinserted the disk and to my suprise (and dismay) it crashed my Amiga when it tried to validate the disk! I managed to make a copy of the disk (using diskcopy) and tried the copy ... Bango! the copy crashed Amy too. Third copy, same thing. I have yet to try this on another machine, but has anyone else ever had this happen? What causes it? I wouldn't think that the validator could crash itself by reading a bad disk - but since it can, it looks like we have another thing to have nightmares about... Peter Philip Dalhousie University Halifax, Nova Scotia ------------------------- Look ma! No disclaimers! -------------------------
engst@batcomputer.UUCP (04/02/87)
Horrors, does pulling a disk out of an Amiga while the drive is on really
kill it? I've never seen a computer that did that, of course with the
exception of a Mac, which won't even give the damn things back when you want
them some times. (A friend once got a disk stuck in a Mac and got angry and
pulled the entire machine apart to get it out. Luckily he was an
engineering/CS whiz and could put it back together.)
adammwm@eris.UUCP (04/02/87)
In article <588@batcomputer.tn.cornell.edu> engst@batcomputer.UUCP (Adam C. Engst) writes: >Horrors, does pulling a disk out of an Amiga while the drive is on really >kill it? I've never seen a computer that did that, of course with the >exception of a Mac, which won't even give the damn things back when you want This is the result of having a buffer cache. Computers with buffer caches tend to fry the disk if you don't give them time to flush the cache. Worst disk problems I've ever had resulted from pulling a disk from my z80 with cache, not hearing it beeping at me or noticing the message on the screen asking that I put the disk back, and putting in the next disk I wanted to work on. It promply flushed the cache (the full 1/2Meg) onto the new disk, resulting in two very dead disks. As for disks going bad, _every_ computer I've ever worked with has those problems, from Cray's to TRS-80's. Even the Apple ][. Buying high-dollar disks helps, but doesn't solve the problem. Apples ]['s seem to be better than average; but the error checking on the Woz machine is bad enought that hardware engineers claim that the silly thing will write to a pancake without complaining. N.B. - expensive systems have hooks to cover for bad blocks. Either the hardware will reserve tracks to map bad blocks to, or the software will arrange to not use those blocks. On the Cray, installing a new disk involves "flawing" the disk to find the bad blocks, then mapping file system partitions (not what you Unix wizards think they are!) around them. <mike -- Here's a song about absolutely nothing. Mike Meyer It's not about me, not about anyone else, ucbvax!mwm Not about love, not about being young. mwm@berkeley.edu Not about anything else, either. mwm@ucbjade.BITNET
dillon@CORY.BERKELEY.EDU.UUCP (04/02/87)
>Horrors, does pulling a disk out of an Amiga while the drive is on really >kill it? I've never seen a computer that did that, of course with the >exception of a Mac, which won't even give the damn things back when you want >them some times. (A friend once got a disk stuck in a Mac and got angry and >pulled the entire machine apart to get it out. Luckily he was an >engineering/CS whiz and could put it back together.) > adam Only if the Amiga is writing to the drive at the time. I've pulled disks out of spinning drives all the time (when I'm sure it's not writing) without damaging my disks. -Matt
cmcmanis@sun.UUCP (04/03/87)
In article <38@dalcsug.UUCP>, philip@dalcsug.UUCP (Peter Philip) writes: > Yesterday ... I pulled a disk out while the drive light was on... > ... I thought that I would just fix it with disksalv ... I reinserted > it ... it crashed my Amiga when it tried to validate the disk! > > Peter Philip [How's that for creative editing?] The problem with this disk is that the directory structure is corrupt and some types of corruption (like a block pointer to hilbert space) will cause a crash rather than the familiar "Use DISKDOCTOR" message. You might try running DISKDOCTOR on it but specify it by volume name rather than drive name. That way you could pop it in when the "Insert Disk" requester came up. Hopefully DiskDoctor would 'inhibit' the drive before it got validated. -- --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These opinions are my own and no one elses, but you knew that didn't you.
daveh@cbmvax.UUCP (04/04/87)
in article <16084@sun.uucp>, cmcmanis@sun.uucp (Chuck McManis) says: > Keywords: disk trashed validate crash > Summary: Corrupt disk can crash Amiga! >> Yesterday ... I pulled a disk out while the drive light was on... >> ... I thought that I would just fix it with disksalv ... I reinserted >> it ... it crashed my Amiga when it tried to validate the disk! >> Peter Philip > > The problem with this disk is that the directory structure is corrupt > and some types of corruption (like a block pointer to hilbert space) > will cause a crash rather than the familiar "Use DISKDOCTOR" message. > You might try running DISKDOCTOR on it but specify it by volume name > rather than drive name. That way you could pop it in when the "Insert > Disk" requester came up. Hopefully DiskDoctor would 'inhibit' the > drive before it got validated. > -- > --Chuck McManis DiskSalv wouldn't run into trouble with that type of clobbered disk, but it currently doesn't do anything to prevent the validator from kicking in, and in this case, crashing. The problem's very simple to correct; in the case of DiskSalv, if I had provided the capability of specifying the output drive before the disk is inserted, all of the higher level AmigaDOS stuff could have been cut out. DiskSalv seems to work pretty well for a number of cases, but it does have its problems. I'm thinking of a number of things I could have done better back then, but of course, hindsite is all-knowing. Anyway, I've come to learn that many of the things that I didn't account for in DiskSalv were based on my ignorance that these things could ever occurr. So if you've got things that DiskSalv or any other recovery utility can't recover, let me know via E-Mail and maybe we can get together and fix your thing, and maybe add to the power of a new DiskSalv release. A new DiskSalv release for devices other that floppies will definately be forthcoming, though based on the limited amount of time I have for this, I can't give any specific release date. If everything goes reasonably well, I might be able to send out a new release by June. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dave Haynie Commodore Technology // /| ___ __ __ __ {ihnp4|caip|rutgers}!cbmvax!daveh |\ // /_| | / \ / \ / \ Commodore rarely admits to knowing me, \\// / | +--+ | | | | | | much less sharing my personal opinions. \/ / | |___ \__/ \__/ \__/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~