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Systems Administration Notes

This page stores both generic notes, as well as additional pages and categories related to systems administration. My general modus operandi here is to start taking notes here, and then to break things out into separate pages when they get too large.

Documentation Projects

Blogs / Sysadmin Sites

Bootloaders

Scripting Languages

Bash

Regular Expressions

Monitoring / Debugging

Memory

Networking

Application-Layer Protocols

HTTP

TCPDump Tutorials

Security

Storage

ACLs

RAID-5

A list of pages discussing why not to use RAID5:

An article on the RAID "write-hole", which seems to be especially salient for RAID5:

Tape

  • tar tvf \<device_name> - Read the file name from the tar header for the current file that the tape is pointed at.

Database vs Filesystem

AI / Neural Network / Deep Learning Workloads

Identity Management / User Management

Applications

Web Servers

  • An analogy: web/app servers / load balancers belong to the same sub-class of problems that HPC schedulers treat, but are just more narrow in scope.
  • A 301 redirect in nginx for HTTPS requires a cert because the packet needs to be decrypted for nginx to inspect the host field of the packet header.
  • Canned nginx Configs (to use as templates)

Databases

Virtualization

  • Apparently KVM and Virtualbox are incompatible / can't be run simultaneously. See here for an idea on how to handle that (or just don't do that at all because it doesn't make too much sense to begin with- quoth the older and wiser me).
  • Xen Networking
  • Importing an OVA into KVM

Containerization

Cloud Computing

  • If an AWS S3 upload is MultiPart, the ETag attribute of an S3 bucket object is not an MD5 hash. It is the hashes for each part uploaded concatenated, plus a dash and the number of parts uploaded (see here).

S3-compatible object stores

Windows/Linux Compatibility

Tools