I was showing this to a few people at DebConf and people seemed
generally in favour of the UI changes, so I thought I'd post it for
wider comment here.
The process of setting up complex block devices (LVM, RAID, crypto) in
partman is currently rather tedious. You have to separately edit each
partition you want to use as a physical volume, change its Use as:
field, and then a Configure foo menu item appears that lets you
assemble the physical volumes. This is very cumbersome, and it also has
discoverability problems - if your goal is to set up LVM, you can't even
see the menu item that lets you do that until you're part-way through
the process.
I'd like to introduce an alternative way to do this that's more
goal-oriented: in other words, I'd like people to be able to select
Configure the Logical Volume Manager, select from a menu of all the
partitions that *could* be used as LVM PVs, and have partman-lvm
automatically set them up for them.
The attached set of three patches implements this for each of
partman-lvm, partman-md, and partman-crypto. In the case of
partman-crypto, I had to add a menu, which both brings it into line with
LVM and RAID and will allow adding a way to deconfigure encrypted
volumes in the future (#381892). The partman-md patch is rather
complicated because I had to cope with the way it trims partitions
already selected as active devices when prompting for spare devices; the
code in this patch is the result of several attempts, and most of my
previous attempts had much twistier uses of IFS that I eventually
rejected.
Talking through this with Max Vozeler identified several problems that
I'd still like to fix:
* There are several common chunks of code that should be moved into
partman-base.
* It'd be nice to show more detail in the partition menus, especially
including a status field and the mountpoint. We can't quite reuse the
standard partition tree as this relies on a separate line to identify
the disk device, which doesn't really work here, but we could do
something similar.
* There's some weird bug in handling of locked devices; the LVM menu,
at least, offers the underlying devices of configured encrypted
volumes when it shouldn't.
* Max suggests that we might exclude partitions with mountpoints to
reduce the probability of mistakes. This seems to make sense - d-i
doesn't automatically set up mountpoints, so if a partition has a
mountpoint then it's because the user deliberately gave it one.
If you'd like to try this out, then I guess a reasonable way to do so
would be to play with a current Ubuntu installation image:
http://cdimage.ubuntu.com/releases/karmic/alpha-3/
(alpha release produced today, CD-sized; use the server option)
http://cdimage.ubuntu.com/ubuntu-server/daily/current/
(server daily build, may be arbitrarily broken)
http://cdimage.ubuntu.com/netboot/karmic/
(netboot images, may be arbitrarily broken though usually not too
bad)
Thanks,
--
Colin Watson [cjwat...@ubuntu.com]
=== modified file 'choose_method/lvm/choices'
--- choose_method/lvm/choices 2007-12-05 20:18:24 +
+++ choose_method/lvm/choices 2009-07-13 21:40:14 +
@@ -1,45 +1,11 @@
#!/bin/sh
-. /lib/partman/lib/base.sh
+. /lib/partman/lib/lvm-base.sh
dev=$1
id=$2
-cd $dev
-
-lvm=no
-if grep -q /dev/md $dev/device; then
- # LVM on software RAID
- lvm=yes
-elif grep -q /dev/mapper/ $dev/device; then
- # LVM on device-mapper crypto
- if type dmsetup /dev/null 21; then
- device=$(cat $dev/device)
- if [ $(dmsetup status $device | cut -d' ' -f3) = crypt ]; then
- lvm=yes
- fi
- fi
-fi
-
-# sparc can not have LVM starting at 0 or it will destroy the partition table
-if [ $(udpkg --print-architecture) = sparc ] \
- [ ${id%%-*} = 0 ] [ $lvm = no ]; then
-exit 0
-fi
-
-if [ $lvm = no ]; then
- open_dialog VALID_FLAGS $id
- while { read_line flag; [ $flag ]; }; do
- if [ $flag = lvm ]; then
- lvm=yes
- fi
- done
- close_dialog
-fi
-
-if [ $lvm = no ]; then
- exit 0
-fi
+pv_allowed $dev $id || exit 0
db_metaget partman/method_long/lvm description
=== modified file 'choose_partition/lvm/choices'
--- choose_partition/lvm/choices 2007-12-05 20:18:57 +
+++ choose_partition/lvm/choices 2009-07-09 09:42:49 +
@@ -3,8 +3,9 @@
. /usr/share/debconf/confmodule
. /lib/partman/lib/lvm-base.sh
-# Only show menu option if there is at least one LVM PV
-[ $(pv_list | wc -l) -gt 0 ] || exit 0
+# Only show menu option if there is at least one partition that can be used
+# as an LVM PV
+[ $(pv_list_allowed | wc -l) -gt 0 ] || exit 0
db_metaget partman-lvm/text/configure_lvm description
=== modified file 'choose_partition/lvm/do_option'
--- choose_partition/lvm/do_option 2008-07-31 11:29:20 +
+++ choose_partition/lvm/do_option 2009-07-22 13:12:33 +
@@ -43,15 +43,32 @@ do_display() {
}
do_vg_create() {
- local pvs pv output vg
+ local pvs line pv output vg pathmap
pvs=
+
