What are the canonical answers we've discovered over the years?

Question

We've created, appointed, or otherwise identified certain question/answer pairs that are the canonical answer for certain problems. A list of these problems is given in the accepted answer below.

Please:

• Post an Answer to nominate a question for inclusion. Questions explicitly posted for the purpose of creating a canonical Question/Answer can skip this.
• Delete content that has been merged into the official list. Try to keep this post neat and tidy.

Answer 1

These are the questions we have identified as Canonical:

Capacity Planning

• Generic Capacity Planning: Can you help me with my capacity planning?
• How do you do Load Testing and Capacity Planning for Databases
• How do you do Load Testing and Capacity Planning for Web Sites

Career

• Starting out: What a beginner should know/learn for sysadmin job?

Datacenter Design

• Fire Suppression: What's the best fire suppression for a server room?

Documentation

• Getting started with documentation

EMail & Spam

• Incoming: Fighting Spam - What can I do as an: Email Administrator, Domain Owner, or User?
• Bystander: How to stop people from using my domain to send spam?
• Outgoing: How to send emails and avoid them being classified as spam

Hardware

• Why is business-class storage so expensive?
• What are the different widely used RAID levels and when should I consider them?
• What is a Storage Area Network, and which benefits does it have over different storage solutions?

Hosting provider/server hardware shopping

• Dedicated server or Cloud Hosting?
• Use Google Apps/Cloud Services as a Domain Controller Replacement

Infrastructure Software

• What is Active Directory and how does it work?
• Can I have multiple DHCP servers on one network?

• What is Group Policy and how does it work?

  DNS
  • How long does it take for DNS records to propagate?
  • What is a glue record?
  • How to use DNS/Hostnames or Other ways to resolve to a specific IP:Port
  • Why does DNS work the way it does?

Licensing

• Can you help me with my software licensing issue?

Networking

• Not getting expected performance from 100Mbps Ethernet network
• Hairpin NAT: How come I can't redirect TCP ports on this wireless router?
• What tool do you use to monitor your servers?
• What am I looking for in a Monitoring Solution?
• How does IPv4 Subnetting Work?
• How does IPv6 subnetting work and how does it differ from IPv4 subnetting?
• How do VLANs work?

General Unix/Linux OS Stuff

• Why is Linux reporting "free" memory strangely?

Security

• How do I deal with a compromised server?
• Linux Webserver Rights: What are the best linux permissions to use for my website?
• Misbehaving users: What should I do about this user?
• Restricted Shell: How to restrict the users' shell allowing to execute shell programs
• How to convince a big boss that he does not need administrator privileges?
• Tips for Securing a LAMP Server
• How do I deal with the removal/eradication of an unknown worm on our network?
• Why is "chmod -R 777 /" destructive?

SSH

• ProxyCommand: How to configure a shortcut for an SSH connection through a SSH tunnel

Terminal Server (RDS)

• Find out the bottleneck for windows remote desktop server (Terminal server)

Uptime

• 100% uptime for a web application
• reaching 99.9999% uptime

Unix (General)

• Unix Server Partitioning & Filesystem Layout

Virtualization

• Enabling hardware virtualisation BIOS; anything to beware?

Web Servers

• mod_rewrite: Everything you wanted to know about mod_rewrite rules but were afraid to ask
• Picking the right MPM (on *NIX systems): How do I select which Apache MPM to use?
• One-click (x)AMP: Why not use a WAMP stack?, Meta: What to do with XAMPP/MAMP/WAMP questions
• IIS7: What are the differences between Websites, Directories, Virual Directories, and Applications in IIS 7?
• SNI: Multiple SSL domains on the same IP address and same port?

Windows (General)

Answer 2

I notice that we have a lot of "My cronjob is not working" questions, and the answers are often the same (Check your environment (PATH), look in the logs, remember that output is sent to the MAILTO address (root by default), optionally send your errors to syslog instead of via email).

The following questions are similar:

• Bash script is not working as cron job (Answer: remember that cron has a special environment)
• trac-admin hotcopy not working when run from crontab (Answer: remember that cron has a special environment)
• Parts of script not executing in cron (Answer: remember that cron has a special environment)
• Ubuntu server cron.d file not working - newbie question

I am looking for Canonical answers to these common questions. If one cannot be found, I may write one myself if I have time.

Answer 3

List of Canonical Topics that do not have a Q/A yet or need improvement:

Career

• When does my small business need a SA
• How many users/servers/whatever should a SA be responsible for
• How do I protect my company from my IT guy?
• Value of Certifications?

Datacenter Design

• What to look for in a server rack?
• Physical server security
• What Data Center room routine maintenance tasks should be done?

Infrastructure Software

• How is DNS related to Active Directory and what are some common configurations that I should be aware of?
• Windows AD Domain naming recommendations
  Needs Merging: What should I name my Active Directory?

Networking

• Hairpin NAT (et al)
• Find out the bottleneck for windows remote desktop server (Terminal server)
• How to set up VLAN network
• Firewall Theory
  • Depth of Defense : Several border firewalls in the same network
  • IDS/IPS?
  • DLP/ILP?
• Cabling...
  • I've inherited a rat's nest of cabling. What now?
  • How do you organise the cables in your racks?
• IPv6
  • NAT/Security
    • IPv6: the end of NAT?
    • Switch to IPv6 and get rid of NAT? Are you kidding?
  • Addressing (may roll into How does IPv6 subnetting work and how does it differ from IPv4 subnetting?)
    • How do you set up IPv6 alongside an IPv4-based NAT configuration?
    • IPv6 without nat but what about an isp change?
    • Do all IPv4 IP addresses have an IPv6 equivalent?
    • IPv6 configuration for my private network when prefix delegation is not supported by the provider?
    • What is the IPv6 equivalent to IPv4 RFC1918 addresses?
  • Tunneling
    • Teredo - how to connect to host behind NAT?
    • 6to4
    • 6RD
    • ISATAP
  • Support
    • How do IPv4 only applications work on IPv6 only hosts?
    • Are many IP addresses on a single interface a bad thing?
    • Can a global IPv6 address be NAT'd to an internal IPv4 address at a firewall-level?
    • Should I use IPv6 only or both IPv4 and IPv6 in my web server?

Web Servers

• Apache vHost
• Apache .htaccess/overrides

Enterprise Storage

Create one Question that covers "ES" topics, including questions about all this. Merge these answer into that Question (keeping them separate/complete answers).

• What is a Storage Area Network, and which benefits does it have over different storage solutions?
• What is the difference between SAN, NAS and DAS?
• Why is business-class storage so expensive?
• How should I set up my Fibre Channel (FC) network?
• Tuning iSCSI storage
• 2.5 inch drives versus 3.5 inch drives
• Reliability of ssd drives

Answer 4

In response to Why The Hostility, I wrote this for consideration as a canonical Q/A:

What are the basics of running a Web Server?