Linux lover consumed a quarter of the network
- Reference: 1690183633
- News link: https://www.theregister.co.uk/2023/07/24/who_me/
- Source link:
This week our story comes from "Charlie" who, some quarter of a century ago, was working on his PhD at "a large tertiary education institution on the south coast." The south coast of what? He doesn't say. Charlie is an enigma.
Charlie shared an office space with four other students, each of whom had their own desk with their own computer. Charlie's PC was running Windows NT4, but his dearest wish was to run Debian Linux like all the cool rebellious kids.
[1]
The problem was that the Debian installation required "something like a dozen CD-ROMs." These could be had by downloading from a federation of servers called Sunsite, which had an outpost nearby. Unfortunately, the internet connection in Charlie's office was slow and unreliable at the best of times, even when it wasn't being shared four ways.
[2]
[3]
Then Charlie had a brainstorm. Sunsite supported not only the FTP protocol, but also NFS, which of course had all sorts of tricky ways of maintaining and restoring itself over dodgy connections. Slow, to be sure, but at least it would download eventually.
All Charlie had to do was mount Sunsite as an NFS share, and copy the disk images to a local drive. That was where the quirks of NT4 came in, and this proved too complex a task.
[4]
Not for Charlie, though. His roomie, who he's asked us to call "Martin" so we will, was already running Linux and allowed Charlie shell access to his machine. Charlie used that to copy data from the NFS mount to a local drive on Martin's machine.
[5]Network died, hard, during company Christmas party, leaving lone techie to fix it
[6]Turning a computer off, then on again, never goes wrong. Right?
[7]Hacking a Foosball table scored an own goal for naughty engineers
[8]Security? Working servers? Who needs those when you can have a shiny floor?
The download began. Very slowly, but that was to be expected. (Note that nowadays you can download the latest Debian in about the time it takes to read this column, even on an average household connection. We've come a long long way.)
That was Monday afternoon. Monday night, it's still going. Tuesday morning it's not tone yet, but Charlie can see data is trickling through, so leaves it alone.
Tuesday afternoon, there's a knock on the door. The departmental sysadmin and someone from the university network team are there, looking concerned.
"Which machine in here is called martin?"
[9]
"This one," replied Martin.
"Whatever you're doing on there, can you stop it? You're using up a quarter of the university's bandwidth."
Oops.
Remember what we mentioned before about how NFS had all sorts of neat tricks to restore dodgy connections? Well, funny story.
As Charlie puts it: "It turns out that running NFS, which has infinite retries over UDP, is not a particularly good idea over a long-distance network with reliability issues. The two machines end up screaming at each other as fast as they can: 'I CAN'T HEAR YOU!' 'WHAT DID YOU SAY?' 'I SAID I CAN'T HEAR YOU! SAY THAT AGAIN!' 'WHAT DID YOU SAY? THIS LINE IS TERRIBLE!'"
So not much of what was happening over that very chatty connection was Charlie's data.
The download was stopped, the sysadmins got their network back, and an important lesson was learned.
Also, Charlie found someone who already had the CD-ROMs for Debian and could post them to him. Those were the days.
Have you ever fixed one problem, only to create a whole other one no-one saw coming? Tell us all about it in [10]an email to Who, Me? and we will make your exploits the stuff of legend.
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He's very lucky he didn't get himself a WAN from using the network...
He just got told to packet in
Yeah, he was a bit naughty...
...and without parity, even - that's the killer bit...
Charlie Says
Never play with matches download that which can be posted to you in 48 hours"
Re: Charlie Says
Yeah, taking that long to download, I'd be baud waiting...
Re: Charlie Says
Maybe pop out for a byte to eat whilst you're waiting...
Re: Charlie Says
[Bah! Too slow to edit!]
Nice coincidence on the title MyffyW! I watched all of the Charley Says a few days ago - proper memory lane! [1]Charley says...all 6 episodes .
[1] https://www.youtube.com/watch?v=CVOMK6YD6fw
Unnecessary
"Hamm is the code name for a former Stable Debian distribution. It was released on July 24th 1998 as Debian GNU/Linux 2.0. It was superseded by Debian/Slink on 09 Mar 1999."
(https://wiki.debian.org/DebianHamm)
I had mine through snail mail from some nice volunteer, IIRC linking from the Debian webpage. No chance to download it via a 33.6 modem.
Rule one...
...Never underestimate the bandwidth of a vehicle packed full of hard drives rolling down the road.
Rule two...
...Never talk about a vehicle packed full of hard drives rolling down the road.
Re: Rule one...
In the UK, that would either be a vehicle stuck in a traffic jam in central London, or stationary on the M20, trying to get to Dover.
Re: Rule one...
Which is why we have Rule two.
Re: Rule two...
ie.
Rule two...
...Never talk about a vehicle parked full of hard drives.
Re: Rule one...
> stationary on the M20
Aka [1]Operation Stack
Which really gets one right in the old pedantry nerve: that is a FIFO not a LIFO! They aren't stacking their operations, they are queueing!
Although calling it Operation Queue would just get it confused with SOP on the M25.
[1] https://en.wikipedia.org/wiki/Operation_Stack
Re: Rule one...
Canonically, that's "Never underestimate the bandwidth capability of a station wagon full of mag tape."
The quote is often attributed to Tanenbaum in 1996, but it was a common expression when I was at DEC long before that ... and I remember a similar comment from a student at Stanford in the early '80s when a professor expressed surprise at one of the vaxen already running the latest BSD build, released just a few hours before. Conversation went "How on earth did you get that code across the network that fast?" answer was "My motorcycle's latency might be sub-par, but it still has a much higher bandwidth capability than your network!".
Even today there are sites that have serious bandwidth limitations, such as odd research post in Antarctica where the glory of an 8Mbit satellite connection is shard by 20-100 people depending on the time of year.
Yep.
According to a buddy who works down there, uploading selfies is by appointment only ... and uploading research data is positively glacial.
Re: Yep.
Icy what you did there...
Positively Glacial
Oh dear, Jake! Icy what you did there!
Here -->
[Edit: Bloody hell Korev! In before! I was snowed under!]
Re: Positively Glacial
> [Edit: Bloody hell Korev! In before! I was snowed under!]
Maybe the network's being a bit flakey today...
Re: Positively Glacial
Yeah, damage at the base station - apparently caused by a penguin byte, then comms were frozen.
Home page label
Could you tag the article with "Who, Me?" please? Took me a little while to find today's.
Re: Could you tag the article with "Who, Me?" please?
Since they are running short of material, they skipped it in order to set up a "Who me Who me" story for next week :-)
Bandwidth...
It's not that many years ago that, as an experiment, they tried downloading a film (movie for non-Brits) from a server in London to a computer in Nottingham (130 miles or so by road), at the same time they sent a USB drive strapped to a pigeon's leg. The USB drive arrived before the download completed.
We had an incident 10-12 years ago with TomTom updates over our 2 meg leased line. The downloading PC sent the request to the Akamai server hosting the updates which duly sent the update, then when the server hadn't received an acknowledgement within a relatively short time frame it sent it again, and again, and again... I believe at one point there were 7 copies of the update being downloaded simultaneously, and not a lot else being done. Shutting down the PC concerned and terminating the connections cured the immediate problem, as did telling the user to not try that again. I then gradually blocked every Akamai address on the firewall to prevent a recurrence.
"something like a dozen CD-ROMs."?
Really? 'Debian installation required "something like a dozen CD-ROMs." "something like a dozen CD-ROMs."'?
On https://youtu.be/tQQCcvFUzrg?t=206 you can see Debian on just one CD.
Debian DoS'ed
I remember when i was still in university that a professor once shared the tale of when he DoS'ed the debian servers by trying to set up a mirror at the university lab, with the only caveat that being an academic institution, the Uni had 2 10gig lines to the literal national backbone... Let's just say that he's not welcome anymore on the other debian mirrors....
Looks like Charlie was visiting some CD sites...