Friday, July 27, 2007

First a list of references

Starting from where to get the CD image everything has been new to me. So the first place to find was, the download location. This one is for the so called amd64 which Marius educated me was just a common moniker for all 64 bit [including Intel processors].
And have to start this one with a big Thank You to Marius Ducea for showing me around this OS. I have been on FreeBSD most recently @ Y.
I am working in an environment running the etch release (Debian GNU/Linux 4.0)

Some basics that helped me get on firm ground:

  1. wrong time zone : I installed the OS and set my server in the wrong timezone. Use /usr/sbin/tzconfig.


    • Use ntpdate to keep date in sync with a time server.

    • Suggest a simple script like this,

      #!/bin/sh
      /usr/sbin/ntpdate ntp.somedomain.com

      Pay attention to the note in the setup - do not query the level 1 NTP servers.

  2. wrong hostname: /bin/hostname ; and set it in /etc/hostname, /etc/hosts for permanence across reboot. Good howto in Marius' blog post.
  3. Changing IP: ifconfig, and /etc/network/interfaces.
  4. redundant NIC setup - if you 2 NICs on board then ifenslave [version 2.6] is the way to go. A good howto. We did it slightly differently.

    • Took out the iface definitions from /etc/network/interfaces
    • Added ifenslave lines to /etc/rc.local
    • And added sysctl -p in rc.local after ifenslave setup.
    • modprobe bonding mode=active-backup miimon=100
      ifconfig bond0 10.1.2.3 netmask 255.255.255.0 up
      ifenslave bond0 eth0
      ifenslave bond0 eth1 ## or eth2 as the case maybe
      route add default gw 10.31.1.254
      sysctl -p > /dev/null
      exit 0 ### important to come out cleanly for boot sequence


  5. Setup your /etc/hosts, /etc/resolv.conf right ; otherwise be prepared for name lookup timeouts. SImple rules to follow there:


    • Add local hosts to /etc/hosts - no need to look up name servers for those. NOTE: Does mean you have to maintain it when you change names/IPs

    • Find a good name server that is local - normally your ISP can help here. for critical services, good idea is to setup your own dns cache server like djbdns

  6. Debian support for aptitude is one of the biggest advantages in my opinion - having come from the yinst world at Y.


  7. # apt-get update ## first step after installation to get security patches
    # apt-get openssh-server openssh-client sudo ntpdate