This is a quick guide to mounting a qcow2 disk images on your host server. This is useful to reset passwords, edit files, or recover something without the virtual machine running.
Step 1 - Enable NBD on the Host
modprobe nbd max_part=8
Eric Wolf typetetris
typetetris
/ killbutmakeitlooklikeanaccident.sh
Created
July 17, 2022 15:24
— forked from moyix/killbutmakeitlooklikeanaccident.sh
Script to inject an exit(0) syscall into a running process. NB: only x86_64 for now!
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| #!/bin/bash | |
| gdb -p "$1" -batch -ex 'set {short}$rip = 0x050f' -ex 'set $rax=231' -ex 'set $rdi=0' -ex 'cont' |
typetetris
/ mount_qcow2.md
Created
April 6, 2022 09:58
— forked from shamil/mount_qcow2.md
How to mount a qcow2 disk image
typetetris
/ fork-is-evil-vfork-is-good-afork-would-be-better.md
Created
February 28, 2022 20:46
— forked from nicowilliams/fork-is-evil-vfork-is-good-afork-would-be-better.md
fork() is evil; vfork() is goodness; afork() would be better; clone() is stupid
I recently happened upon an implementation of popen() (different API, same idea) using clone(2), and so I opened an issue requesting use of vfork(2) or posix_spawn() for portability. It turns out that on Linux there's an important advantage to using clone(2). I think I should capture the things I wrote there in a better place. A gist, a blog, whatever.
So here goes.
Long ago, I, like many Unix fans, thought that fork(2) and the fork-exec process spawning model were the greatest thing, and the Windows sucked for only having [exec*()](http://pubs.opengroup.org/onlinepubs/9699919
typetetris
/ Rust Optimization.md
Created
September 1, 2021 10:55
— forked from jFransham/Rust Optimization.md
typetetris
/ latency.txt
Created
July 6, 2021 15:06
— forked from jboner/latency.txt
Latency Numbers Every Programmer Should Know
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| Latency Comparison Numbers (~2012) | |
| ---------------------------------- | |
| L1 cache reference 0.5 ns | |
| Branch mispredict 5 ns | |
| L2 cache reference 7 ns 14x L1 cache | |
| Mutex lock/unlock 25 ns | |
| Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Zippy 3,000 ns 3 us | |
| Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
| Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |
typetetris
/ haskeller_competency_matrix.md
Created
September 11, 2020 09:52
— forked from graninas/haskeller_competency_matrix.md
Haskeller competency matrix
See also List of materials about Software Design in Haskell
| Junior | Middle | Senior | Architect | |
|---|---|---|---|---|
| Haskell level | Basic Haskell | Intermediate Haskell | Advanced Haskell | Language-agnostic |
| Haskell knowledge scope | Learn you a Haskell | Get programming with Haskell | Haskell in Depth | Knows several languages from different categories |
| Get programming with Haskell | Haskell in Depth | Functional Design and Architecture | ||
| [Other books on Software Architecture in Haskell](https://github.com/graninas/software-design-in-haskell#Books-on-S |