Learning Functional Reactive Programming

Functional Reactive Programming (FRP) is a programming technique that I think hasn’t filtered down to the level of workaday programmers (like myself) but is well-regarded in the academic community.
Upside is that it could make writing Gtk and web applications much simpler.
Downside is that no one from the academic world has ever managed to explain FRP [...]

guestmount and virt-inspector

I was asked on IRC what the purpose of the $(virt-inspector …) clause is from the previous example:

$ guestmount $(virt-inspector –ro-fish /dev/vg_trick/Debian5×64) /tmp/rich

Firstly $(…) is the cool modern way to write shell `backquotes`. As well as being cool and modern, it’s also better than using backquotes because you can nest it.
What does the virt-inspector [...]

Fedora virt-* commands

virt-* commands in Fedora, or (in italics) coming up:

virt-cat
Download a file from inside a VM.

virt-clone
Clone a VM.

virt-convert
Convert a VM disk image.

virt-df
Show real disk space used.

virt-dmesg
Show kernel messages from VM.

virt-edit
Edit a file in [...]

virt-top 日本語で

virt-top is the sane replacement to xentop. Virt-top looks and acts like the familiar top(1) command, displays virtual machines, and uses libvirt so it works with just about every virtualization system out there. It also has cool features for sysadmins, like you can use it to log stats into a database or spreadsheet [...]

Graphical “virt-df”

(Click to enlarge if WordPress.com squashes the image)
What I learned yesterday:

Programming Gtk apps is horrible. Gtk leaves far too much fiddly detail up to the programmer, and doesn’t have sensible defaults.
Programming Gtk apps with OCaml has an impedance mismatch (Gtk is imperative and highly mutable, OCaml is functional and mostly immutable). [...]

Dan uses OCaml + CIL to analyze libvirt’s locking patterns

Nice write-up of Dan Berrange’s experiences using OCaml + CIL to analyze libvirt here.
My earlier work using libvirt and CIL.

Stuck

Somedays I just spend the time going round in circles, and this was one of those days. Not really for lack of work, but lack of knowing the Right Thing to do. Below I’ll describe the problem I had today.
If you look at a virtual machine from the point of view of libvirt, [...]