What the most embarrassing technical mistake you ever made?

Ever spend hours or days trying to figure why something isn't working and then realise - oh - I forgot to XYZ.

I have a long list but I thought I would share my latest faux pax since I probably would not admit this other than anonymously.

I bought myself a new motherboard and cpu about 4 months ago. About 2 weeks ago, I finally cracked it open to setup. I've been mucking around with that mobo/cpu for the past 2 weeks. But I couldnt get it to POST. There was power to the drives, fans, etc. I initially thought that it was the power so I dragged out some old power supplies and even bought a brand new one. I replaced the memory and then I even bought all new memory for it. Eventually, I got frustrated and figured it had to be a DOA mobo and bought a new motherboard from a different company. The new mobo arrived today and I hooked it up and added the cpu from the "defective" mobo and it worked the first time. Feeling very smug, I concluded that it was poor quality original mobo.

As I was removing the "defective" board from the other case, it hit me - I never plugged in the 12v ATX CPU power.

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ptilsen

Virtualized a PDC Emulator using hardware time to an ESXi server that hadn't had time configured in the BIOS or OS. As soon as the errors started, I realized what I did.

That's what comes to mind, anyway.

Agent6376

Not very technical, but I had my project manager approve about 3 grand on Cisco copper GBICs only to find out that the model of 2960 was one of just a few that ONLY supported fiber GBICs. To this day there's $3000 of GBICs sitting in the Vice President's office, and I hear about it often (this was about 2 months ago)

Moral of the story - let the PSEs from Ingram Micro handle it (if you work for a VAR or run your own business). If they screw it up and give you the wrong ones, they'll take them back. If you just straight up order it on your own - as soon as you open the bag they're yours.

Lizano

Man, touch topic, there's a list...

I hit shutdown instead of reboot on a device located at an unmanned site.

Overlooked an interface being set to half duplex, I looked at the sh run like 5 times, missed it every time.

undomiel

Most embarrassing technical mistake ... well I've already told the story before about deleting a production virtual machine that the backups hadn't been working for. I guess next in the list would be a toss-up between when I yanked the power cords on the wrong server (and my slow brain was going "Wait, this one has two power cords and the one we're doing maintenance on only has one ... oh well") or when I was troubleshooting a BES authentication issue and completely migrated it to a new install on a new server -- unnecessarily! Found out that it was just the deployed version of IE refused to login but if an older version was used, or Opera/Chrome/Firefox, then you could login just fine. Of course it didn't help that I was being fed the misinformation that everyone was down when in reality they just couldn't login to activate a new user.

Trifidw

4 years and not one (noticeable) mistake.

rsutton

Powered off a file server I was RDP'ed in to thinking it was my local machine.

Bloogen

I somehow disabled the WAN NIC on an Amazon EC2 server. It was only a test server but it was one of those mistakes where as soon as you hit the button your stomach sinks.

CodeBlox

paul78 wrote: »

Ever spend hours or days trying to figure why something isn't working and then realise - oh - I forgot to XYZ.

I have a long list but I thought I would share my latest faux pax since I probably would not admit this other than anonymously.

I bought myself a new motherboard and cpu about 4 months ago. About 2 weeks ago, I finally cracked it open to setup. I've been mucking around with that mobo/cpu for the past 2 weeks. But I couldnt get it to POST. There was power to the drives, fans, etc. I initially thought that it was the power so I dragged out some old power supplies and even bought a brand new one. I replaced the memory and then I even bought all new memory for it. Eventually, I got frustrated and figured it had to be a DOA mobo and bought a new motherboard from a different company. The new mobo arrived today and I hooked it up and added the cpu from the "defective" mobo and it worked the first time. Feeling very smug, I concluded that it was poor quality original mobo.

As I was removing the "defective" board from the other case, it hit me - I never plugged in the 12v ATX CPU power.

I have had a similar case. With my new mobo, I plugged in a PCI-E 6 pin connector into the 4x4 PS connector on the mobo. Powered it on and it started sparking and smoking. I immediately turned it off and realized what I had done.

Sponx

Trifidw wrote: »

4 years and not one (noticeable) mistake.

That's the key.

tpatt100

Years ago put up a WUS server on the city network. Back then you really had to tweak the GPO since it was pretty lacking in features. Well I found out the hard way how many systems were really out of date and missing patches. I got calls all day from people who had their XP machines rebooting numerous times because they were so out of date their machines would get a batch,install some more, reboot, get some more, reboot.

Later I realized I should have added containers one at a time and tested it our first.

the_Grinch

Here, I spent about two hours trying to join a PC to the domain and kept getting a denied message. Open a ticket with the university and still have the issue. Finally go under my desk and find that the network cable wasn't plugged in all the way.

At my last job we were doing a equipment migration for a customer to a new data center. Really easy job, we unplug everything and someone else would move it. So the senior engineer with me says we should probably start plugging stuff in at the new location. Just as he says "hang on, let me see if this is AC or DC" I plug a PC into a socket and poof power supply starts smoking. So I offer to replace the power supply with one from another pc and after removing everything found at they were different models and it wouldn't work.

Mistakes = experience

rwmidl

I've tripped over a network cable attached to an Exchange server. Moral of the story = keep your cabling neat

Asif Dasl

It was a few years ago now, but you know those Laptop IDE to USB adapters (pictured) well I plugged it in and was 1 pin out - it looked OK when I put it on but when I plugged it in to the USB - I got that burnt electronic smell which is unmistakable... everything on the hard drive was gone in an instant. I explained the situation to the customer and he was very understanding thankfully (nothing of real value was on the laptop), I bought a replacement hard drive and put Windows back on - I'll never forget it though.

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Sett

The latest one was that I forgot to save the config of a router after a major change which of course had to experience power outage a few days later.

Hypntick

Apparently shortly after starting this job over a year ago, I worked a ticket that was a combo file restore from backup and then a change in the backup location (file level backups). Did the file restore, verified everyone was happy and closed the ticket. A couple of weeks back, two quickbooks databases were overwritten (how I would love to know), in the location that was supposed to be backed up. Since the change hadn't taken place, a years worth of accounting data was lost. When I was investigating the issue and found the old ticket I was at home, needless to say I had a few drinks and started transferring anything I needed off my work laptop, certain I would be let go when I walked in the door the next day. Luckily I have a very understanding boss. Also luckily, it wasn't a total loss, the client just happened to have paper of everything that was lost.

MAC_Addy

About a year ago I switched out our Nortel PBX to a Cisco UC560. When I installed the UC560 I dismantled the old system. I even took the liberty in cutting (with scissors) the wires going into the 3 66 blocks connecting all the offices.

About an hour after I cut all those wires, something went wrong... All the cisco phones were in the "registering" phase. I couldn't ping the UC, so I connected with a console cable.

I got the infamous, "would you like to enter the initial configuration dialog". I almost poo'ed myself. Though, I thought to myself "okay, you just forgot to do a copy run start". I got all all back up and running - did the copy run start and backed everything up to my tftp server. About 10 minutes later, all phones went down again.

Turns out that my UC560 died. Cisco did a warranty replacement.

I managed to get the old Nortel backup and running, with the key users back on the 66 block within 20 minutes.

Though, this isn't really a technical mistake - I definitely thought it was at the time.

Letter

Had two putty sessions open at the same time, one to a core router and one to a test device... you can see where this is going.

Qord

I just got back to the office from a road trip. Had to visit a remote site to deploy some wireless AP's, about an hour and a half away. I made the trip twice today...forgot the AP's when I left this morning. Almost six hours of driving for 20 minutes worth of work.

RobertKaucher

Letter wrote: »

Had two putty sessions open at the same time, one to a core router and one to a test device... you can see where this is going.

All of TE wrote:

::groans::

Letter wrote:

I know, I'm in the future, too...

And that's how that would go if it were a Mike Birbiglia stand up show. It's easy to see when you're in the future!

pcgizzmo

When I was brand spanking new at my first consulting gig at my first customer I was under a table trying to sort out some wires and pulled a plug for whatever reason not thinking and took out 3 of their servers. They had no backup power etc.. I just stayed under the desk for a minute or two while my red face faded.

Not long after this I was at a city government office and a lady asked me to put some paper in a printer for her. I pulled out the drawer and didn't fan the paper or square it up and just stuck it in there and closed the door. Her first print jammed the printer. She walked over and took out the paper and did everything I should have done and said "Man, you are new aren't you?" I was just nervous and I new more than I let on but my nerves got the best of me in those early days.

I still make stupid mistakes but I've never pulled another plug. (Knock on wood)

cxzar20

Blew away the BGP configuration on a remote device...thank God I had a tech at the site to do a quick power cycle.

Lizano

Letter wrote: »

Had two putty sessions open at the same time, one to a core router and one to a test device... you can see where this is going.

Oh yeah I did that one too hehe...

matt333

i was playing around with some NAT settings and took the internet down, and almost had a heart attack trying to log back into the firewall.. i still laugh about it

Akaricloud

I was doing some inventory and needed to check the asset tag on the bottom of the Dean's laptop. She asked me if she needed to save anything and I told her no it would just take a second. Properly undock the laptop, record the asset tag ID, redock it and it bluescreens. The hard drive ended up being dead and she lost everything that she had open.

I ALWAYS ask them to save first now no matter what I'm doing.

alan2308

My second PC build, a pair of Athlon MP processors and a Gigabit motherboard. It was my first dual processor system and it slipped my mind to put the HSF on the second processor. Apparently I didn't leave it powered up long enough to let all of the magic smoke out because it still works to this day 10 years later.

unclerico

Configuring a LAG on a Juniper stack and accidentally configured LACP on ae0 instead of ae1 which took out all back end connections to our POS NetApp.

No matter what, always own up to your mistakes even if you think it might cost you your job. Integrity is worth more than money.

wd40

Auditors are in office and asking for Server Backup logs, at the same time we had an issue with low disk space on an old server, I decided we do not need backup software on it, so having open sessions to the old server and the new one that I need the logs from, I proceeded with uninstalling the backup software from the new server .. and we do not have backups of the backup database ..

So I gave them a 1 month old report and they where happy with it, it is a good thing that my boss was on leave and the auditors just wanted to finish and go home early

RomBUS

Haha I love your guys stories, laughed at some of them

Way back at my first IT job I was given the responsibility of just simply making sure the conference room PC was turning on and working so they would be able to use it for their meeting. So I check to see if the PC booted up and Windows loaded fine. I was so sure that everything was OK and I had thought to myself "wow no actual work to do". So I stick around until their actual meeting....so one of the guy had logged in and went to the IE browser and started getting pop-ups of advertisements and pornographic images. I had then realized I didnt log in to see if the PC was actually healthy and only made sure it turned on, everyone had thought I had put a virus on there and using it for my own entertainment. About 20+ people all turned their heads in my direction. In embarrassment I had to call my boss and he had to cover my ass.

Lesson learned: Cover your ass and cover all bases before thinking everything is OK

epicdean

I added a Vlan to gi2/12 instead of the port-channel on a PE router, taking down alot of people for about 2 min.

Architect192

Hmmm... Been in IT since 1989... So many things happened

Back in the early days, working at a computer store, I was installing a hard drive in a client's PC and the only screw i had left was a wood screw... Well, it threaded properly so I used it. Until the pointy end slipped over the circuit board and toasted the drive upon powering up.

My claim to fame though, it this one. I was newly hired as a sysadmin. The previous guys did a piss poor job at maintaining things so in my first few days, I started cleaning up. First disabling the 4 administrator accounts (guys before me) that were still domain admins and still active, then removing old user accounts, and PC accounts. On a 120 user domain, there were over 400 systems registered...

So far so good. I then tackle the systems cleanup part. In NT4, the users & computers tool had an option to show only workstations and only servers. Thing is, in the "workstations only" view, the servers were listed but greyed out. So I deleted them

This was in my first week there. 20 servers nuked from the domain. Ok, no biggie, I ran to the server room and re-registered them into the domain but that was one heck of a stressful moment for me!

Oh and that day where I decided to rearrange the power cables wiring on a server with dual power supplies... I figured it only needs one to run so I decided to pull one plug at a time... First one brought it right down (HP netserver). So I finished the job and turned it back on lol. It was down anyway. What's another minute

Like someone else said before me, NEVER hide the truth. Own up to your mistakes. I always did.