the ghost of installation horrors past        


the original inspiration for this rambling collection of computer geek stories was a topic-drift post on (void) --- here's the excerpt:

Date: Thu, 11 Nov 1999
Subject: (void) oops did I do that?

Hmmm, interesting idea for a new thread. What's the worst fuck-up you've (or someone else) made on a computer system?

i've cleaned up my response and added to it considerably, because i think the story is kinda funny and dumb enough to keep.


the worst fsck-ups typically come from losing data in the installation process... i was repartitioning my drive and upgrading my slackware system...  i had only one disk, so it was an elaborate shuffling scheme.

you see, the "c" in "-zcvf" means "create". i meant to type "x", as in "extract"... but "c" and "x" are right next to each other on the qwerty keyboard, and i'm a poor typist, not to mention that i'd been at this for sixteen straight hours (most of the time waiting for windows to reboot and operating systems to install).

when you tell tar to create an archive, it creates an empty header. since i didn't give it any input files, it just sat there, waiting on stdin, which wasn't coming. it sat there for a few seconds before i realized that i'd just overwritten the 4 or 8 most important bytes in the file --- the ones that tell it how long the archive is.

so, all my data, over 80MB (zipped), was still there on the disk... but i had no idea which sectors held it, and absolutely no way to find out.

it's quite sad when you realize there's nothing you can do.

and i'd been so diligent that whole time...  to fuck up on the very last step...

 

incidentally, the repartitioning and shuffling scheme worked perfectly, aside from the tar mishap, and kept me happy all the way up until i got a new version of slack.

that next time was even more convoluted, to be honest.  i'd been playing around with other operating systems, like caldera's OpenDOS, and somehow OpenDOS managed to mung up my boot sector and wouldn't let it go.  i was pretty picky about my boot sector --- although i no longer use NT on my home computer, i use its boot loader to select between Win95, BeOS, and Linux, entirely because the NT boot loader uses a menu to let the user select the OS, and my roommates had typically been too non-computer-savvy to figure out how to type in an OS name at the lilo boot prompt.

so, i had to get rid of this boot sector somehow.  and while i was at it, why not install newer versions of the OSes i already use?  but i wished to avoid th hell i went through above...

at this point i was working at th UK college of engineering's computing center.  we had lots of unix machines and lots of ethernet.  so i brought my home machine in after hours, hooked it up to the network, mounted via NFS a drive on my office server, and went to dinner while my machine tarred its entire contents over the network to my server.

then i could pull the ace, the trick to get rid of that pesky boot sector problem.  i booted a linux installation floppy, and executed this simple command:

dd bs=512 if=/dev/zero of=/dev/hda

i let that run for about three minutes (i had a 3.5 GB hard disk on /dev/hda), then hit ^C and started fdisk to survey the damage.  nothing.   blank disk.  no boot sector, no partition table, no nothing, wiped clean.

WOOHOO!

then i installed Win95SR2.

then i created my linux partitions and installed slackware.

then i installed NT, but immediately wiped out all of NT except for the bootloader-related files.

then i mounted the NFS drive and copied all my data back into place, config files and all.

much, much, much easier.

 

and even better than that --- when i had the opportunity to upgrade my office machine from a 1GB disk to a 6GB disk... i installed both disks in the machine, with the 6GB disk as a slave, partitioned and formated the second drive, tarred the contents of my current partitions over to the new drive, mounted the new drive and changed some config settings, shut down and switched the new drive to be the master and the old drive to be the slave, booted the system from a floppy, installed lilo on the new drive, rebooted from the drive to make sure it worked, and then removed the old drive and handed to my cubicle-mate (who wiped it clean and installed WinNT on it).  start to finish: two hours, almost all the time waiting on tar.

 

i really am a geek, huh?


Sat Nov 13 13:58:48 EST 1999