User Do's and Don'ts

Preserving our Control Network

• DON'T use control network unless absolutely necessary. This means:

  • DON'T use full node names such as ping node1.YourExperiment.YourProject when communicating between nodes in your experiment

    • DO use short names such as ping node1. This ensures that traffic goes over experimental network.

  • DON'T generate traffic to 192.168.x.x network.

    • DO use addresses of experimental interfaces. These can be from any IPv4 address range, depending on your NS file, but are often from the 10.10.x.x address range.

Preserving our File System

• DON'T store large files (e.g. uncompressed kernel source) in your home or project directory unless you need them in multiple experiment instances.

  • DO store these files locally on a node, e.g., in /tmp folder. If you need more disk space on a Linux or FreeBSD node you can mount more to /mnt/local by doing

    sudo mkdir /mnt/local
    sudo /usr/local/etc/emulab/mkextrafs /mnt/local
    user=`whoami`
    sudo chown $user /mnt/local

Remember to transfer the files to your home directory before you swap out to save them.

• DON'T transfer large (>500 MB) files frequently between your home or project directories and a local directory on your experimental machine.

  • If you need to regularly save and read large files that persist between experiment instances create a ticket and we will help you use our ZFS storage.

• DON'T perform large (> 500 MB) or frequent (< 10 s) reads/writes on your experimental nodes into your home or project directory

  • DO perform these reads/writes on a local disk (/tmp or /mnt/local on experimental machines)

• DON'T compile software or kernels in your home directory

  • DO compile them on a local disk (/tmp or /mnt/local on experimental machines)

Preserving CPU Cycles on users

• DON'T compile large files or run CPU intensive jobs on users.deterlab.net.

  • DO allocate experimental nodes, store files locally and compile/run jobs there.