Control: severity -1 important Control: clone -1 -2 Control: retitle -2 Installation manual should warn about the use of LVM partition types Control: reassign -2 installation-guide
On Sun, Jan 18, 2015 at 04:24:43PM +0000, Steve McIntyre wrote: >On Wed, Nov 19, 2014 at 03:36:19PM -0600, Drake Wilson wrote: >>FYI: I've just confirmed with partman-lvm 99 (plus whatever libparted is in >>the last Debian testing weekly ISO) that MBR disklabels using 8e (Linux LVM) >>as a type code for LUKS are also affected by this. So it's not just GPT. >>It's arguably even more dangerous for MBR, because the type code space is >>so small that collisions should be expected, but util-linux's fdisk in MBR >>mode also provides a 0xda code for "non-FS data", so users in that case may >>be less tempted to default to the underlying volume type. > >Hi Drake, > >I've just reproduced your findings here, and I'm looking at the code >right now. As you've guessed, the partman-lvm code currently >unconditionally tries to set up *every* partition with an LVM >partition type, regardless. If you're interested the code is in >partman-lvm/choose_partition/lvm/do_option:do_initial_setup(). It >calls into partman-lvm/lib/lvm-base.sh:pv_create(), and pv_create() >checks to see if the partition is already set up as a PV (by calling >"pvs") - if so, it leaves it alone, otherwise it calls "pvcreate". > >So... There are a few things to do here: > > 1. Don't do what you're doing! This is one of the few areas where the > partition type matters in d-i > 2. I'm looking to add a check in pv_list() so it will either: > (a) Ignore partitions tagged with LVM type but some other > filesystem/blkid contents; OR > (b) Warn about such partitions and ask the user what to do. > >2(a) looks much easier, I'll be honest, so that's my plan for now. And after playing with this a lot more, I'm going to have to admit defeat I'm afraid. The code in partman-lvm is very flexible in terms of allowing user choice, but that actually makes this particular case even harder. The best thing I can tell you is: don't use the partition types for LVM unless you really want to use LVM on those partitions! Sorry. :-/ We should add a warning in the installation manual for this corner case, at least. I've opened a new bug for that above. -- Steve McIntyre, Cambridge, UK. st...@einval.com There's no sensation to compare with this Suspended animation, A state of bliss -- To UNSUBSCRIBE, email to debian-boot-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/20150126154631.ga7...@einval.com
