Panzer of the Lake's CLI Wisdom

Description

This is a two-panel meme using the 'Panzer of the Lake' format. The top panel features a black-and-white photo of a soldier with a rifle standing on the shore, looking at a tank turret submerged in the water. The text overlay reads, 'O panzer of the lake, what is your wisdom?'. The bottom panel shows the tank again, delivering its wisdom in a text overlay: 'dd is a very dangerous command, use of instead of if and you end up overwriting what you are trying to backup!! Notice how the keys o and i are next to each other? So be very very very careful.' The meme's humor comes from receiving a highly specific, critical piece of technical advice from a surreal, wise entity. The advice itself is a legendary piece of Linux/Unix folklore: the 'dd' command is a powerful disk-copying tool, but accidentally swapping the 'if' (input file) and 'of' (output file) parameters - an easy typo since 'i' and 'o' are adjacent on QWERTY keyboards - can catastrophically overwrite the source disk instead of the destination, leading to total data loss. It's a painful rite of passage for many system administrators and developers

Common Tags

CLI CommandLineInterface DataLoss Linux ShellScriptingLanguages BackupStrategy DiskManagement DiskImaging Sysadmin

Comments

Anonymous ★ Top Pick Some learn about the `dd` `if`/`of` typo from a wise panzer in a lake. The rest of us learn it from a 3 a.m. incident ticket and a resume update

Anonymous ★ Top Pick

Some learn about the `dd` `if`/`of` typo from a wise panzer in a lake. The rest of us learn it from a 3 a.m. incident ticket and a resume update
Anonymous

dd if=/dev/sda | ssh backup 'dd of=/dev/sda' - the only deployment pipeline where one missed i turns your DR site into a sunken relic
Anonymous

The dd command has earned its nickname 'disk destroyer' for good reason - it's the only tool where a single typo can turn your carefully planned backup strategy into an impromptu lesson in disaster recovery, all because some sadist at Bell Labs decided that 'if' and 'of' were perfectly reasonable parameter names despite 'i' and 'o' being keyboard neighbors
Anonymous

The panzer speaks truth from its watery grave - a fitting metaphor for the dd command, which has sent more data to the depths than any ransomware campaign. Senior engineers know that 'dd' doesn't stand for 'disk duplicator' but rather 'data destroyer,' especially at 3 AM when muscle memory swaps if= and of=. The real wisdom? Always triple-check your parameters, use dd with status=progress, and remember: the keys 'o' and 'i' being adjacent on QWERTY keyboards has caused more production incidents than any zero-day exploit. Some say the tank sank during WWII; others whisper it was a sysadmin who fat-fingered a dd command on the wrong block device
Anonymous

DD's if/of swap: keyboard neighbors plotting filesystem Armageddon since SVR4
Anonymous

dd isn’t a backup tool; it’s a wire-speed footgun - flip if= and of= and you’ll measure your RPO at disk throughput
Anonymous

If your DR plan hinges on remembering if vs of, you don’t have backups - you have a recurring postmortem
@alexolexo 5y

Holy shot, he's right
@sylfn 5y

Just don't use dd
@slnt_opp 5y

Do you guys know anybody mistaken like this?_.
1. @Stepan_Poznyak 5y
  
  I don't know, but that's easy. I and O are neighbors
  
  @slnt_opp 5y
  
  I mean, I see the point, but never heard/read about this issue, while it's even mentioned in Wikipedia article about dd (at least Russian)
  
  @RiedleroD 5y
  
  the problem is that dd is used so rarely that it doesn't really occur. At least that's my experience
@UQuark 5y

I have a habit to twice-check my dd command before execution