Re: [Hampshire] error competition
(yes I know this is an old thread -- I've been away in sunny Devon) On 08/20/2011 12:21 AM, Ian Grody wrote: Setting no read/write/exec perms on all files and subdirs in a certain folder on a shared user system... root@local: chmod -R 000 / instead of, chmod -R 000 ./ Wouldn't this be just as good: chmod -R 000 . and possibly safer because '.' can only mean 'the current directory', whereas typos such as '/' or '/.' when you mean './' can have embarrassing results? cheers Chris -- Chris Dennis cgden...@btinternet.com Fordingbridge, Hampshire, UK -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On Fri, 2011-08-19 at 10:21 +0100, Edward Beckmann wrote: Hi All As it's friday and I have just caused my longsuffering sysadmin to moan at my stupidity yet again , I thought I would offer a challenge for amusing typos or human errors. Examples could be: No systems administrators should be long-suffering - that's why mistakes are made:) who can do the most damage to a system with the fewest number of keystrokes? The Boss when he attempts to test the UPS as you walk out of the office to go home for the weekend. what duff error gives the most spectacular failure? Kernel maintainers latest un-bootable kernel. what error can trigger the longest chain of disasters? The one that ends up with a series of sales people being fired. I am sure you get the gist If I didn't I'd be deca thousands of pounds better off. Bonus marks for anyone brave / foolhardy enough to say I did ... as opposed to I knew someone who did ... I don't do bonuses, only sell them;) Damian -- Interlinux Engineering Foundation http://www.interlinux.org.uk Central, non-trading, administration, governance and dissemination of foundation intellectual property and know-how. GPG 8A7E551C signature.asc Description: This is a digitally signed message part -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
[Hampshire] error competition
Hi All As it's friday and I have just caused my longsuffering sysadmin to moan at my stupidity yet again , I thought I would offer a challenge for amusing typos or human errors. Examples could be: who can do the most damage to a system with the fewest number of keystrokes? what duff error gives the most spectacular failure? what error can trigger the longest chain of disasters? I am sure you get the gist Bonus marks for anyone brave / foolhardy enough to say I did ... as opposed to I knew someone who did ... -- Ed -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On 19 August 2011 10:21, Edward Beckmann edward.beckm...@gmail.com wrote: Bonus marks for anyone brave / foolhardy enough to say I did ... as opposed to I knew someone who did ... I have flicked the off-switch (pesky old-style toggles) on an AS/400 crossing my legs while sitting at a terminal in the computer room... -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
who can do the most damage to a system with the fewest number of keystrokes? root@goliath # mount /dev/sda12 /mnt/whatthehellisthis root@goliath # rm -rf /mnt/whatthehellisthis/* root@goliath # mount | grep var /dev/sda12 on /var type ext3 (rw) Bonus marks for anyone brave / foolhardy enough to say I did ... Yep. I did. On a RHL8 system, where all the package management stuff lives in /var. To this day, I am still finding unpackaged binaries of great vintage... Vic. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On 19 August 2011 10:21, Edward Beckmann edward.beckm...@gmail.com wrote: what duff error gives the most spectacular failure? Someone in an Ubuntu support channel complained of data loss when he'd run rsync with --delete and had the source and destination the wrong way round. Goodbye data! Al. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On 19/08/11 10:21, Edward Beckmann wrote: Hi All As it's friday and I have just caused my longsuffering sysadmin to moan at my stupidity yet again , I thought I would offer a challenge for amusing typos or human errors. Examples could be: who can do the most damage to a system with the fewest number of keystrokes? what duff error gives the most spectacular failure? what error can trigger the longest chain of disasters? I am sure you get the gist Bonus marks for anyone brave / foolhardy enough to say I did ... as opposed to I knew someone who did ... Although not in the fewest keystrokes category, perhaps this goes in: duff error *of judgement* gives the most spectacular failure? and what error *of judgement* can trigger the longest chain of disasters?. This would have been back in the days of Slackware 2.x at a guess, I wanted to build something that needed a newer libc version, so with the naive thought of how hard can it be? I embarked on upgrading the core C library on my (i386!) system. A long weekend later, I had a working system again, with the fresh new libc installed - and the software I wanted to build that had started the whole odyssey... still didn't build - thud! Live and learn - and give thanks everyday for VBox.. Chris -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On 19 August 2011 10:31, Michael Pavling pavl...@gmail.com wrote: On 19 August 2011 10:21, Edward Beckmann edward.beckm...@gmail.com wrote: Bonus marks for anyone brave / foolhardy enough to say I did ... as opposed to I knew someone who did ... I have flicked the off-switch (pesky old-style toggles) on an AS/400 crossing my legs while sitting at a terminal in the computer room... In the 'no-keystrokes involved' category I can add causing a custom array processor the size of a single wardrobe to shut down by standing too close to it and blocking tha airflow through its cooling fans. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk -- -- best regards, Victor Churchill, Bournemouth -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
Pointing the reset vector of a pdp11 at the trigger power down register. Power up reset, three bus cycles, power off. -- Bob Dunlop -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
Spare a thought for the hapless soul at our place who thought the big red button he was pressing would test the fire alarm instead of powering down our entire shiny new office. To compound the error the test was rescheduled for the following week and whoever was conducting it did exactly the same thing. Sean -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On 19 August 2011 11:18, s...@funkygibbins.me.uk s...@funkygibbins.me.uk wrote: Spare a thought for the hapless soul at our place who thought the big red button he was pressing would test the fire alarm instead of powering down our entire shiny new office. Ooh, friend of mine did that because the button to shut the power down in this datacentre looks like the button that opens the door in the other datacentre. He missed out on curry that night because he spent the entire evening bringing up Exchange servers. Al. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
** Victor Churchill victorchurch...@gmail.com [2011-08-19 11:01]: On 19 August 2011 10:31, Michael Pavling pavl...@gmail.com wrote: On 19 August 2011 10:21, Edward Beckmann edward.beckm...@gmail.com wrote: Bonus marks for anyone brave / foolhardy enough to say I did ... as opposed to I knew someone who did ... I have flicked the off-switch (pesky old-style toggles) on an AS/400 crossing my legs while sitting at a terminal in the computer room... In the 'no-keystrokes involved' category I can add causing a custom array processor the size of a single wardrobe to shut down by standing too close to it and blocking tha airflow through its cooling fans. ** end quote [Victor Churchill] Also in the 'no-keystroke involved' category I managed to crash 3 computers merely by standing close(ish) to them. This was on my degree and we were learning 68000 assembler on Sinclair QLs. The one I was working on crashed for some reason (just stopped working while I was typing in iirc). The lecturer told me to go and stand behind one of the other students as we were at capacity of available computers. Moments after I got there this QL crashed too, so we were both asked to go and stand behind different students. The other one carried on working fine, but the one I stood near crashed. At which point the other student got to join another of the still working QLs and it was suggested that since it was pretty close to the end of the lesson I could leave early!! Oddly these days I seem to have the opposite effect. I often get to a customer and find they can no longer replicated the problem that was easy to reproduce before I got there! -- Paul Tansom | Aptanet Ltd. | http://www.aptanet.com/ | 023 9238 0001 == Registered in England | Company No: 4905028 | Registered Office: Crawford House, Hambledon Road, Denmead, Waterlooville, Hants, PO7 6NU -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On 19 August 2011 10:21, Edward Beckmann edward.beckm...@gmail.com wrote: Hi All As it's friday and I have just caused my longsuffering sysadmin to moan at my stupidity yet again , I thought I would offer a challenge for amusing typos or human errors. Examples could be: who can do the most damage to a system with the fewest number of keystrokes? what duff error gives the most spectacular failure? what error can trigger the longest chain of disasters? I am sure you get the gist Bonus marks for anyone brave / foolhardy enough to say I did ... as opposed to I knew someone who did ... Bad design decisions: 1) Have the light switch on the wrong side of the machine room door. So when entering the server room, you have to stretch round, in the dark, behind the door to reach the light switch. Issue componded by the big red button being placed right next to the light switch! Fortunately, the customer insisted in entering the dark server room before me. Company: A large bank in the city. 2) Having the power cable between an IBM mainframe and the UPS trailing across the floor and then inviting a BT engineer in to install a phone socket. Result: power cable knocked loose from IBM mainframe. Causing it to take 49 hours to rebuild/check its database before coming back online. I visited 3 days after this happened to install the device that needed the phone socket! I was told the story and shown the power cable to avoid! Company: A large company providing information to city customers. 3) This was public news some time ago at an ISP. An employee deleted the wrong PARTITIONS on a SAN storage array. Resulting is a majority of their customer's emails being lost for good. Both the live and the network backup partitions were deleted. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On 19 August 2011 11:35, Paul Tansom p...@aptanet.com wrote: Oddly these days I seem to have the opposite effect. I often get to a customer and find they can no longer replicated the problem that was easy to reproduce before I got there! I got that one. I turn up, wait in reception chatting to the receptionist and when my contact arrives everything is working well. I then leave only to be called back 1 hour later. The problem turned out to be a network cable (the old coax ones) was running under the receptionist's chair, and whenever it was squashed by her chair the network went down. But when she was talking to people in reception, the chair was not on the cable. Cheers James -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On 19 August 2011 10:32, Alan Pope a...@popey.com wrote: On 19 August 2011 10:21, Edward Beckmann edward.beckm...@gmail.com wrote: what duff error gives the most spectacular failure? Someone in an Ubuntu support channel complained of data loss when he'd run rsync with --delete and had the source and destination the wrong way round. Goodbye data! Thank goodness for '--dry-run' ... -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On 19 August 2011 11:48, Victor Churchill victorchurch...@gmail.com wrote: Thank goodness for '--dry-run' ... Indeed, that was the second thing he learned that day after the sequence of parameters :D Al. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On 19 August 2011 10:32, Alan Pope a...@popey.com wrote: On 19 August 2011 10:21, Edward Beckmann edward.beckm...@gmail.com wrote: what duff error gives the most spectacular failure? Someone in an Ubuntu support channel complained of data loss when he'd run rsync with --delete and had the source and destination the wrong way round. Goodbye data! Second job I had, Data General Eclipse, Assembler programs... ROLIO DP0 MT0 instead of the other way round. The old ones stick around... Al. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk -- -- best regards, Victor Churchill, Bournemouth -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
Good datacentre story: in one of our Mediterranean branches numerous boxes would crash out inexplicably at the same time each week. In the end it was decided to put someone in the datacentre an hour or so before the event. What he witnessed was a cleaner show up with a bucket and mop, power off the machines, slosh water all over the shop, mop it up and then power everything on again! Sean Sent from my HTC -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
how about this one that I have actually performed myself: rm -rf .* the scenario was I wanted to delete all folders in a subtree including folders beginning with a dot (.) to hide them from a normal ls listing. instead it deleted everything in the subtree .. AND everything in the supertree (../ then ../../ then ../../../ all the way up to / and then following back down again into every subdirectory of /) -- Regards, The Honeymonster aka Daniel Llewellyn -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition - thanks
Thanks guys - really brightened my day (though Sean, your datacentre story bears a remarkable resemblance to the series of deaths in a certain hospital bed where the polisher was plugged in instead of the monitors ;-) ). Funny the lack of windows stories - is it because it is difficult to tell the operator error disasters from the ones that come in the box? Good weekend all. -- Ed -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition - thanks
** Edward Beckmann edward.beckm...@gmail.com [2011-08-19 13:36]: Thanks guys - really brightened my day (though Sean, your datacentre story bears a remarkable resemblance to the series of deaths in a certain hospital bed where the polisher was plugged in instead of the monitors ;-) ). Funny the lack of windows stories - is it because it is difficult to tell the operator error disasters from the ones that come in the box? Good weekend all. ** end quote [Edward Beckmann] Where I used to work one of the other administrators changed some permissions on an NT4 drive and then filtered the changes down through the subdirectories. Unfortunatly this directory contained user and departmental shares that each had appropriate permissions set to restrict access to the appropriate people / groups. It took a long while to rebuild the permissions structure, although iirc there was a tool in the resource kit that could back up the permissions so they could be re-applied easily. -- Paul Tansom | Aptanet Ltd. | http://www.aptanet.com/ | 023 9238 0001 == Registered in England | Company No: 4905028 | Registered Office: Crawford House, Hambledon Road, Denmead, Waterlooville, Hants, PO7 6NU -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On 08/19/2011 10:21 AM, Edward Beckmann wrote: Hi All As it's friday and I have just caused my longsuffering sysadmin to moan at my stupidity yet again , I thought I would offer a challenge for amusing typos or human errors. A while ago I typed dd if=/dev/sda1 of=/dev/sda2 when I meant dd if=/dev/sda1 of=/dev/sdb1 on a client's server. Yes, I did have a backup. cheers Chris -- Chris Dennis cgden...@btinternet.com Fordingbridge, Hampshire, UK -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
Yes, I did have a backup. Some weeks back, a customer of mine typed something like make proj=foo clean To clean up his project. Except that he didn't. He typed make proj= foo clean The Makefile wasn't all that well written, so when it tried to rm -rf ./$proj , it did quite a number on the rest of his code. No, he didn't have a backup. No, he hadn't checked his work into svn, as corporate standards require. I earnt many brownie points for getting his data back :-) Vic. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
From: hampshire-boun...@mailman.lug.org.uk [mailto:hampshire-boun...@mailman.lug.org.uk] On Behalf Of Edward Beckmann Sent: 19 August 2011 10:21 To: hampshire@mailman.lug.org.uk Subject: [Hampshire] error competition Funnily enough, today I did rm -rf * but in a directory which was one too high. For some reason, it took me a good 20 seconds to kill it - not sure why. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On Friday 19 Aug 2011, Michael Pavling wrote: On 19 August 2011 10:21, Edward Beckmann edward.beckm...@gmail.com wrote: Bonus marks for anyone brave / foolhardy enough to say I did ... as opposed to I knew someone who did ... I have flicked the off-switch (pesky old-style toggles) on an AS/400 crossing my legs while sitting at a terminal in the computer room... I've done that with boxes too, most annoying as it's always in the middle of doing something important! -- Adam Trickett Overton, HANTS, UK Deck of Cards: $1.29. 101 Solitaire Variations book: $6.59. Cheap replacement for the one thing Windows is good at: priceless -- Shane Lazarus -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
Hi Daniel, On Fri, Aug 19, 2011 at 01:01:17PM +0100, Daniel Llewellyn wrote: how about this one that I have actually performed myself: rm -rf .* the scenario was I wanted to delete all folders in a subtree including folders beginning with a dot (.) to hide them from a normal ls listing. instead it deleted everything in the subtree .. AND everything in the supertree (../ then ../../ then ../../../ all the way up to / and then following back down again into every subdirectory of /) Are you sure? Was this not Linux? rm on Linux doesn't recurse through ..: $ cd /tmp/ $ mkdir -vp foo/bar/baz mkdir: created directory `foo' mkdir: created directory `foo/bar' mkdir: created directory `foo/bar/baz' $ cd foo/bar/baz $ rm -rv .* rm: cannot remove directory `.' rm: cannot remove directory `..' Also on the topic of disasters, if anyone has not seen this gem it's worth a read: http://lug.wsu.edu/node/414 of course these days you would expect a quicker disaster recovery without needing to sacrifice a goat with a black candle like this.. Cheers, Andy -- http://bitfolk.com/ -- No-nonsense VPS hosting Eyecon freecycle is for dating single mothers signature.asc Description: Digital signature -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
Hi, On Fri, Aug 19, 2011 at 19:12, Andy Smith a...@strugglers.net wrote: Hi Daniel, On Fri, Aug 19, 2011 at 01:01:17PM +0100, Daniel Llewellyn wrote: how about this one that I have actually performed myself: rm -rf .* Are you sure? Was this not Linux? rm on Linux doesn't recurse through ..: $ cd /tmp/ $ mkdir -vp foo/bar/baz mkdir: created directory `foo' mkdir: created directory `foo/bar' mkdir: created directory `foo/bar/baz' $ cd foo/bar/baz $ rm -rv .* rm: cannot remove directory `.' rm: cannot remove directory `..' memory serves that it was on Ubuntu 10.04LTS. Cheers, Andy -- Regards, The Honeymonster aka Daniel Llewellyn -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
On Fri, 19 Aug 2011, Michael Pavling wrote: On 19 August 2011 10:21, Edward Beckmann edward.beckm...@gmail.com wrote: Bonus marks for anyone brave / foolhardy enough to say I did ... as opposed to I knew someone who did ... I have flicked the off-switch (pesky old-style toggles) on an AS/400 crossing my legs while sitting at a terminal in the computer room... I once powered down a Mac with a large amount of unsaved work on it... It was back in the days of floppy drives and I was a PC user, never used a Mac before, so I hit the button by the disk drive to eject the disk... Turns out that wasn't the way to eject a disk on a Mac :( Andy -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
About 25 years ago, I got to the 29th floppy disk out of 30 when installing SCO UNIX on a PC and mistakenly hit the PC's power button rather than the floppy disk eject button. Suffice it to say, there was no Continue installation option, I had to start all over again and sit there for another 2 hours reinstalling it. --Peter On 19 August 2011 21:11, Andy Random andy.ran...@gmail.com wrote: On Fri, 19 Aug 2011, Michael Pavling wrote: On 19 August 2011 10:21, Edward Beckmann edward.beckm...@gmail.com wrote: Bonus marks for anyone brave / foolhardy enough to say I did ... as opposed to I knew someone who did ... I have flicked the off-switch (pesky old-style toggles) on an AS/400 crossing my legs while sitting at a terminal in the computer room... I once powered down a Mac with a large amount of unsaved work on it... It was back in the days of floppy drives and I was a PC user, never used a Mac before, so I hit the button by the disk drive to eject the disk... Turns out that wasn't the way to eject a disk on a Mac :( Andy -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/**mailman/listinfo/hampshirehttps://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --**--**-- -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] error competition
In message cacaqtbfhsn+b1twem0fxypdx9q7uveo2rpxb+fhqkjxtd0-...@mail.gmail.com,
Edward Beckmann writes:
Hi All
As it's friday and I have just caused my longsuffering sysadmin to moan at
my stupidity yet again , I thought I would offer a challenge for amusing
typos or human errors. Examples could be:
who can do the most damage to a system with the fewest number of keystrokes?
what duff error gives the most spectacular failure?
what error can trigger the longest chain of disasters?
I am sure you get the gist
Bonus marks for anyone brave / foolhardy enough to say I did ... as
opposed to I knew someone who did ...
Excellent questions.
Two things spring to mind.
Firstly, when I was a {sys,net}adm in the University of Bath in the late
'90s, I used to run regular nmap scans of the campus networks to look
for machines with known vulnerabilities. The site was predominantely a
Sun customer so unfortunately a very large number of machines suffered
from bug #4178455.
Basically, nmap triggered a problem such that the next time you closed
a scanned socket the machine would panic. It didn't panic right away.
I'd run the scan weekly and a hapless sysadm would run:
kill -HUP pid-of-inetd
or try to shutdown the machine any time after that and his/her machine
would panic.
I was quite highly regarded amoung the admins around the site so they
often turned to me for help. It was some weeks before I figured out
the cause of the strange panics they were seeing (to be fair I saw a
fair number myself as I owned more machines than most) and was able to
suggest a patch. They were very grateful (less so when I admitted the
cause).
I dread to think how much time was wasted due to my careless scanning.
The number keystrokes to weeks of confusion ratio was pretty high.
The second is more likely to be repeated and thus perhaps more
educational (with respect to learning from my mistakes and it is
Linux-related). I don't recall exactly what I was doing but it was
something like moving a bunch of files from /tmp/blah to an existing
directory /opt/blah. I intended to do:
root@host:/opt/blah# mv /tmp/blah/* .
quite simple except I somehow managed to add a single space in (probably?)
the worse place possible:
root@host:/opt/blah# mv /tmp/blah /* .
Thus moving /tmp/blah and everything (except /opt of course[0]) to /opt/blah.
Obviously, nothing worked so I soon spotted what I'd done. Fortunately
I didn't exit the shell.
I tried to fix it:
root@host:/opt/blah# mv * /
bash: /bin/mv: No such file or directory
But 'bin/mv' definitely was there[1]:
root@host:/opt/blah# echo bin/m*v
bin/mv
So, obviously dynamic libraries were a bit broken. Then I remembered a trick
using the dynamic loader directly to execute binaries:
root@host:/opt/blah# lib/ld*.so bin/mv * /
bin/mv: error while loading shared libraries: libselinux.so.1: cannot open
shared object file: No such file or directory
which felt like progress, so I tried:
root@host:/opt/blah# LD_LIBRARY_PATH=lib lib/ld*.so bin/mv * /
Bingo. Everything back where it should be . . . well almost everything
cleaning up /blah had to wait until I'd had a large coffee.
Regards,
Mark.
[0] mv: cannot move `/opt' to a subdirectory of itself, `./opt'
[1] The shell still works so 'echo *' can be used instead of 'ls'. I knew
this as I'd made mistakes and fixed other peoples many times ;-)
I expect a brilliant sysadmin named Icarus Sparry taught me this the
first time.
[2] This is changing a bit with multiarch support. You might have to use the
echo trick to find the right lib/ld*.so file
--
Please post to: Hampshire@mailman.lug.org.uk
Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire
LUG URL: http://www.hantslug.org.uk
--
Re: [Hampshire] error competition
Hm. Sat in a coffee shop, decided to tidy things on the laptop. By
uninstalling old kernels.
Nothing wrong in that. Just type the version number of the OLD ones, not the
kernel that's actually running...
RC
On 19 August 2011 23:41, Mark Hindess list-hants-...@temporalanomaly.comwrote:
In message
cacaqtbfhsn+b1twem0fxypdx9q7uveo2rpxb+fhqkjxtd0-...@mail.gmail.com,
Edward Beckmann writes:
Hi All
As it's friday and I have just caused my longsuffering sysadmin to moan
at
my stupidity yet again , I thought I would offer a challenge for amusing
typos or human errors. Examples could be:
who can do the most damage to a system with the fewest number of
keystrokes?
what duff error gives the most spectacular failure?
what error can trigger the longest chain of disasters?
I am sure you get the gist
Bonus marks for anyone brave / foolhardy enough to say I did ... as
opposed to I knew someone who did ...
Excellent questions.
Two things spring to mind.
Firstly, when I was a {sys,net}adm in the University of Bath in the late
'90s, I used to run regular nmap scans of the campus networks to look
for machines with known vulnerabilities. The site was predominantely a
Sun customer so unfortunately a very large number of machines suffered
from bug #4178455.
Basically, nmap triggered a problem such that the next time you closed
a scanned socket the machine would panic. It didn't panic right away.
I'd run the scan weekly and a hapless sysadm would run:
kill -HUP pid-of-inetd
or try to shutdown the machine any time after that and his/her machine
would panic.
I was quite highly regarded amoung the admins around the site so they
often turned to me for help. It was some weeks before I figured out
the cause of the strange panics they were seeing (to be fair I saw a
fair number myself as I owned more machines than most) and was able to
suggest a patch. They were very grateful (less so when I admitted the
cause).
I dread to think how much time was wasted due to my careless scanning.
The number keystrokes to weeks of confusion ratio was pretty high.
The second is more likely to be repeated and thus perhaps more
educational (with respect to learning from my mistakes and it is
Linux-related). I don't recall exactly what I was doing but it was
something like moving a bunch of files from /tmp/blah to an existing
directory /opt/blah. I intended to do:
root@host:/opt/blah# mv /tmp/blah/* .
quite simple except I somehow managed to add a single space in (probably?)
the worse place possible:
root@host:/opt/blah# mv /tmp/blah /* .
Thus moving /tmp/blah and everything (except /opt of course[0]) to
/opt/blah.
Obviously, nothing worked so I soon spotted what I'd done. Fortunately
I didn't exit the shell.
I tried to fix it:
root@host:/opt/blah# mv * /
bash: /bin/mv: No such file or directory
But 'bin/mv' definitely was there[1]:
root@host:/opt/blah# echo bin/m*v
bin/mv
So, obviously dynamic libraries were a bit broken. Then I remembered a
trick
using the dynamic loader directly to execute binaries:
root@host:/opt/blah# lib/ld*.so bin/mv * /
bin/mv: error while loading shared libraries: libselinux.so.1: cannot open
shared object file: No such file or directory
which felt like progress, so I tried:
root@host:/opt/blah# LD_LIBRARY_PATH=lib lib/ld*.so bin/mv * /
Bingo. Everything back where it should be . . . well almost everything
cleaning up /blah had to wait until I'd had a large coffee.
Regards,
Mark.
[0] mv: cannot move `/opt' to a subdirectory of itself, `./opt'
[1] The shell still works so 'echo *' can be used instead of 'ls'. I knew
this as I'd made mistakes and fixed other peoples many times ;-)
I expect a brilliant sysadmin named Icarus Sparry taught me this the
first time.
[2] This is changing a bit with multiarch support. You might have to use
the
echo trick to find the right lib/ld*.so file
--
Please post to: Hampshire@mailman.lug.org.uk
Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire
LUG URL: http://www.hantslug.org.uk
--
--
Rgds
RC
Robin Catling
Full Circle Podcast
--
Please post to: Hampshire@mailman.lug.org.uk
Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire
LUG URL: http://www.hantslug.org.uk
--
Re: [Hampshire] error competition
Setting no read/write/exec perms on all files and subdirs in a certain folder on a shared user system... root@local: chmod -R 000 / instead of, chmod -R 000 ./ it took a while to get it all back running! On Friday 19 August 2011 10:21:06 Edward Beckmann wrote: Hi All As it's friday and I have just caused my longsuffering sysadmin to moan at my stupidity yet again , I thought I would offer a challenge for amusing typos or human errors. Examples could be: who can do the most damage to a system with the fewest number of keystrokes? what duff error gives the most spectacular failure? what error can trigger the longest chain of disasters? I am sure you get the gist Bonus marks for anyone brave / foolhardy enough to say I did ... as opposed to I knew someone who did ... -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
