Schroot is good! Try schroot. You have LVM set up and some free extents in a vg? Try this:
# Create a new logical volume for a sid chroot lvcreate -n schroot-sid -L1G YOUR-VG-NAME mke2fs -j /dev/YOUR-VG-NAME/schroot-sid # Debootstrap sid into it mount /dev/YOUR-VG-NAME/schroot-sid /mnt debootstrap --keyring=/etc/apt/trusted.gpg sid /mnt http://ftp.uk.debian.org/debian umount /mnt
Then apt-get install schroot and put this in your /etc/schroot/schroot.conf:
[sid] type=lvm-snapshot device=/dev/YOUR-VG-NAME/schroot-sid description=Debian sid priority=5 users=YOUR-USER-NAME root-users=YOUR-USER-NAME source-root-users=root aliases=unstable lvm-snapshot-options=--size 2G
Now, schroot -c sid will make a LVM snapshot of
/dev/YOUR-VG-NAME/schroot-sid, mount it, set it up as a nice working system,
and chroot into it running a shell. Have a look around: resolv.conf is set up,
your home directory is bind mounted, /proc and /sys are mounted.
When you exit the chroot, the LVM snapshot disappears, and
/dev/YOUR-VG-NAME/schroot-sid is unchanged.
If you want to modify /dev/YOUR-VG-NAME/schroot-sid, you just schroot -c sid-source.
In my laptop, I did this:
# schroot -c sid-source (sid)# echo 'APT::Install-Recommends "false";' > /etc/apt/apt.conf.d/50enrico (sid)# apt-get install build-essential pbuilder devscripts fakeroot (sid)# apt-get clean
At this point, to build a debian package like if I were using pbuilder, I do this:
pkgdir$ schroot -c sid (sid)pkgdir$ su -c /usr/lib/pbuilder/pbuilder-satisfydepends (sid)pkgdir$ debuild -us -uc
You can repeat this whole process with lenny and etch, for example, and if you are on an amd64 system, you can also do sid32, lenny32 and etch32.
If you don't want to redownload packages all the time, install
approx and configure the -source chroots
to use it. This also allows you to easily switch all systems from one mirror
to another if, for example, you are traveling abroad.
If you want to do the same as pbuilder update, you can do this:
# schroot -c sid-source (sid)# apt-get update (sid)# apt-get dist-upgrade (sid)# apt-get autoremove (sid)# apt-get clean
You can use schroot -c sid-source for all sorts of permanent maintenance
works.
You can also create persistent named snapshots:
$ schroot -b -c sid -n playground
This will only disappear when you do:
$ schroot -c playground -e
And you can enter the schroot as many time as you want with:
$ schroot -r -c playground
You can also enter a temporary snapshot as many times as you want, by using the
random name that schroot generated for it (you can see it, for example, when
running df or mount).
You fear that lvm snapshots are a little fragile and a little slow at the moment? It's not a problem: your home is bind-mounted inside the chroot, so you can do all the work in your normal home filesystem, without stressing the snapshot.
This is good not only to build packages. For example, now that
svk is broken in sid and lenny, I just
did schroot -b -c etch -n svk, installed svk on it, and then every time I
need svk, I can do schroot -r -c svk and have it ready.
Added links: * using sbuild as a Debian maintainer * a similar article about schroot