Tag Archives: appliances

A 685K Fedora appliance

Using supermin appliances we can make some very small to download Fedora appliances. These ones are under 700K (yes, that’s “K” not “M”).

For Fedora 15, use this link:
http://koji.fedoraproject.org/koji/taskinfo?taskID=3421870

For Fedora 16, use this link:
http://koji.fedoraproject.org/koji/taskinfo?taskID=3421867

For Rawhide, use this link:
http://koji.fedoraproject.org/koji/taskinfo?taskID=3421803

You will need ~600 MB free space in /var/lib since that is where the real appliance gets built. Just install the RPM and run sudo boot-a-fedora-appliance. Then read that script and the README file.

Upstream source:
http://git.annexia.org/?p=a-fedora-appliance.git;a=summary

Advertisements

Leave a comment

Filed under Uncategorized

Supermin appliance – now in febootstrap

Q: Can you fit a bootable Fedora distribution into 100 kilobytes?
A: You bet!*
* by cheating … read on.

Take an ordinary Fedora appliance as made by febootstrap or appliance-creator. The appliance image is big because it contains copies of programs (/bin/bash) and libraries (/lib/libc.so), the kernel and kernel modules. It needs to, to make it self-contained.

But a technique we’ve been using for a few months in libguestfs is to say: we’re booting this appliance on a Fedora host. Let’s strip out all those programs and libraries from the appliance, and we’ll add them back from the host just before we launch it.

I called such appliances “supermin appliances”, and now I’ve ported the functionality from libguestfs into febootstrap so everyone can use it.

A supermin appliance is really small:

-rw-rw-r-- 1 rjones rjones 14K 2009-10-22 12:43 hostfiles.txt
-rw-rw-r-- 1 rjones rjones 87K 2009-10-22 12:43 supermin.img

yet it’s fully bootable, given the right sort of host:

It’s really easy to use the new febootstrap to make your own super-small supermin appliances.

We’ll start with this small shell script to make a supermin appliance:

#!/bin/sh -
distro=rawhide
febootstrap -i bash -i coreutils $distro fedora
febootstrap-minimize fedora
cat > init <<EOF
#!/bin/sh
echo Starting /init script ...
PATH=/sbin:/usr/sbin:$PATH
touch /etc/fstab
mount -t proc /proc /proc
mount -t sysfs /sys /sys
exec bash -i
EOF
febootstrap-install fedora init /init 0755 root.root
rm init
# Create the supermin appliance.
febootstrap-to-supermin fedora supermin.img hostfiles.txt
# Create the ordinary appliance just for comparison.
febootstrap-to-initramfs fedora > ordinary.img

You will need to use febootstrap >= 2.5, and set the distro variable so it exactly matches your base Fedora system (eg. set distro=fedora-11).

The script below can be used to boot the appliance, and it’s what I used to get the screenshot above.

#!/bin/sh -
time febootstrap-supermin-helper \
    supermin.img hostfiles.txt kernel initrd
qemu-system-x86_64 -m 1024 -kernel kernel -initrd initrd

4 Comments

Filed under Uncategorized