Virtualised DICE image - scoping Research and Teaching Unit Work in progress

Overview ➲ Use cases ➲ Software Requirements ➲ Possible solutions to user cases ➲ Problems

Use Cases ➲ Minimal image for specific courses ➲ DICE image for Staff (in Informatics) ➲ DICE(ish) image for IS labs ➲ DICE(ish) image Anywhere

Software Requirements ➲ Multi-platform ● Windows, linux, OS X ➲ Free (or very cheap) ➲ Scriptable management ➲ Support VMDK/VHD ➲ Easily installed ➲ Looked on paper at most of

Why VirtualBox ➲ Multiplatform (host and guest) ➲ Open source (well it was) ➲ Scriptable managment interface allows ➲ creation of Vms, VirtualDisks, filesystems, shared filesystems and directories.... ➲ Easy to install ➲ CLI...did I say scriptable?

Aside: Immutable images and differencing disks ➲ Immutable Image ● Effectively read only image ● Can be used by multiple users ● Can be used over network filesystem (performance) ● Treated by VirtualBox as a block device (~30G for SL6_64) ➲ Differencing disk ● Stores all write changes to Immutable image (/tmp,/var/tmp,/var/lcfg/log.....) ● disk is useless without original Immutable image ● ANY Change to Image breaks DD and hence VM ● Files 1Mb – Gbs

Minimal image for specific courses ➲ Currently have 2 examples ➲ Students need to have root access ➲ Minimal profile image (no X, minimal apps) ➲ Staff take image and add software to suit ➲ Requirements: ● scripts to build VM, capture additions, generate new profile/rpmlist ● System to deliver images ➲ Low development effort, probably low ➲ demand, low overhead.

Dice Image for staff ➲ Currently do this (only for COs) ➲ Produce script to automate install to Self Managed or DICE machine (Graham?) ➲ Issues: ● Not totally automated:- need profile and hostkey:- wallet? ● NAT or another IP ● DICE boxes being outside of DICE wires? ● Have to assume users will have root and obtain root password ➲ Low development effort, medium demand, low overhead

DICE(ish) on IS labs ➲ IS are “willing to discuss” but no VM software currently installed ➲ Requirements: ● Immutable images accessible from IS labs (~29GB) ● Scripts to build the VM ● Space to host the differencing disk....probably 1- 2Gb? ● Consider putting /tmp, /var/tmp or /var on temp filesystem ● If we want full DICE we need a mechanism for generating profiles...possibly lots of profiles! ➲ Med-high development, med demand?, med-high overhead

Dice(ish) anywhere ➲ Updates: ● pull a new 30Gb Image over Broadband? ● Vs ● Pull ~4gb of rpms every time you boot. ➲ DICE ● How does server handle updates (pull only) ● How do you know it's the correct host pulling the profile ➲ DICEish ● How DICEish do you go ● We do a lot of configuration via

Dice(ish) anywhere ➲ Back to the old DICE laptop era? ➲ DICE ● How does server handle updates (pull only) ● How do you know it's the correct host pulling the profile ● Install: install to image or build an image to be configured. ➲ DICEish ● How DICEish do you go ● We do a lot of configuration via components ➲ Updates: ● Pull a new 30Gb Image over Broadband? Or Pull lots of rpms every time you boot ● High development, ??? demand, med overhead

Problems ➲ Updates: ● via new vm images ● Users have to keep creating new vms (support calls) ● Image sizes ● via lcfg-client and updaterpms ● Users need multi-GB filespace for differencing disks ● lots of profiles (or one profile for a group of hosts) ➲ Security ● Running DICE on non dice subnets ● User has root, the root password access to everything