Category: Sysadmin

  • Proving the Network is Not the Problem With iperf – Packet Life

    Proving the Network is Not the Problem With iperf – Packet Life: “When an application fails to perform as expected, the network is often the first thing blamed. I suppose this is because end users typically view the network as the sole limiting factor with regard to throughput, unaware of the intricacies of application, database,…

  • Copying large number of files between two Unix/Linux/OSX Servers

    Here are some quick tip(s) for copying a ton of files between unixy machines really fast. You’re probably thinking “why not use rsync?”…..well rsync can be miserably slow if your source or destination cpu is underpowered. You can always do a rsync after these commands to make 100% certain that everything checks out, but try…

  • OSX Server: Could not setup Mach task special port 9

    com.apple.launchd[1] (0x10f860.cron[43786]): Could not setup Mach task special port 9: (os/kern) no access If you’re seeing this warning/error in your OSX Server log files, it is more than likely caused by cron running jobs for mailman subsystem. Even if the Mail process is disabled in Server Admin, OSX will try to run these cron jobs.…

  • MySQL Replication howto for Snow Leopard…

    We recently upgraded our servers from old XServe G5’s running Tiger to the latest greatest running Snow Leopard. In this small howto I will deal with the procedure I followed to setup mysql master-slave replication between two new servers. I start out with two (master, slave) empty DB’s, setup the replication and then import my…

  • MySQL: Transfering users and priviledges to a new server….

    So this was a great big mystery this morning. How the heck do you transfer the users and their privileges out of a old mysql server and “import” them into a new server. We recently upgraded from OSX 10.4.11 to a couple of spanking new Snow Leopard servers and during the mysql export/import cycle this…

  • When SysAdmins Ruled The Earth…

    Just found this on Cory Doctrow’s blog…..When SysAdmins Ruled The Earth….It’s a great read/listen, specially if you’re a current/former SysAdmin. Here are the different parts read during his podcast over a couple of sessions: Part 1 Part 2 Part 3 Part 4 Part 5 Part 6 If you like to read it yourself here is…

  • Four little Security tools you should install in Ubuntu

    These should probably also be installed under other linux distros (might already be). But for the sake of completeness here they are: 1) denyhosts: great little package that’s already 98% configured after apt-get install process. It runs as a daemon and monitors /var/log/auth.log file for unsuccessful ssh logins and takes measures to ban the originating…

  • Changing DNS hostname on OSX Server

    If you ever need to check the DNS hostname under OSX server here is the command: $ sudo changeip -checkhostnameIf you need to change it (ie: after a DNS table change) use the following command (for OD sites):changeip /LDAPv3/127.0.0.1/ 192.0.0.12 192.0.0.12 old.example.com new.example.comchangeip also has a lot of other uses (ie: if you change the…