libguestfs architecture ASCII art

There was a little bit of confusion about how exactly libguestfs works, so I drew the architecture diagram in wonderful ASCII art … This is what happens when you type guestfish -a disk.img …

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New tool: virt-list-filesystems

$ virt-list-filesystems Debian5×64.img
/dev/debian5×64/home
/dev/debian5×64/root
/dev/debian5×64/tmp
/dev/debian5×64/usr
/dev/debian5×64/var
/dev/sda1

You can also augment this tool with the -a and -l options. The -a option tells it to list swap partitions too. The -l option tells it to show the filesystem type on each partition that was found:

$ virt-list-filesystems -a -l Fedora12.img
/dev/sda1 ext4
/dev/vg_f12×64/lv_root ext4
/dev/vg_f12×64/lv_swap swap

While this is a fairly simple tool, [...]

Prebuilt distributions part 2

In part 1 I discussed how these days Linux Live CDs usually come with a prebuilt disk image of the distro which is simply copied over to the hard disk during installation. (The “old” method was to rpm/dpkg-install the packages which is much more time-consuming). However my first test wasn’t very successful because [...]

Prebuilt distributions part 1

Previously I took a look at unpacking Fedora and Ubuntu live CDs to find out what’s inside them and to ask the question can we use the prebuilt filesystem image that these live CDs contain to quickly create a Fedora or Ubuntu “all-defaults” virtual machine?
This is my first attempt, and it’s not successful, but it [...]

Interview: Virtualization improvements in F12

Lots of virt developers, including me, were interviewed for the Fedora 12 release by Mel Chua.

Looking closer at Fedora, Ubuntu live CDs

Previously I’ve shown you can use guestfish to unpack a Fedora live CD.
I’m interested in whether we can use the contents of these live CDs to mass-install operating systems using libguestfs.
If you imagine that you go through an “all defaults” install of say Fedora or Ubuntu to a new virtual machine, then when you end [...]

Easy introduction to the libguestfs API

Baffled by the 269 calls that libguestfs provides? Read the libguestfs API overview.

Also: Internet News interviews Paul Frields about Fedora 12.
Update: Another favourable F12 article at arstechnica.

mkfs compared on different filesystems

How long does it take to mkfs a 10GB disk with all the different filesystems out there?
See my test results here using the new guestfish sparse / filesystem support. btrfs is “best” and ext3 comes off “worst”.
As a test this is interesting, but it’s not that relevant for most users — they will be [...]

libguestfs launch times

Indulge me while a make a “note to self” about efforts to reduce the time taken by guestfs_launch which boots up the libguestfs appliance.

Time (s)
Operation

2s

Create supermin appliance: This has crept up over time from originally taking about 1/5th of a second to around 2s. Needs attention. Fixed see this [...]

Quick win

I got the libguestfs launch time down from 12 seconds to 9 seconds today, 25% faster!
It turns out that the appliance’s BIOS was waiting for 3 seconds for someone to hit [F12] on the imaginary keyboard. A simple patch to bochs BIOS fixes that … This patch benefits everyone using Fedora and virtualization, [...]