[breezy install] LVM option?

[Colin Watson]

On Mon, Dec 05, 2005 at 01:44:31PM -0500, David Abrahams wrote:
> Well, here we go.  It's a detailed experience report; eventually
> things "work," but they work badly at best.  Who is in charge of
> installer software and should see this info?

That would be me, but unfortunately I don't have time to keep up with
all of ubuntu-users@ and I only saw this mail by dumb luck. Could you
please file this as a bug report in Bugzilla, on the component
'partman-lvm'? Please also attach /var/log/syslog, /var/log/messages,
and /var/log/partman from the installer (once you've finished the
install, these files live in /var/log/installer/ instead).

I'll answer a few of the comments inline here:

>     IDE1 master (hda) - 30.0 GB
>       #1 primary      16.4 MB ext3 Z :-X   /boot
>          pri/log     238.5 MB              FREE SPACE
>       #5 logical      28.8 GB        :^)   lvm
>     LVM VG Ubuntu, LV root - 28.5 GB Unknown
>       #1 28.5 GB      :-X  ext3              /
>     LVM VG Ubuntu, LV swap_1 - 1.2 GB Unknown
>       #1  1.2 GB      :-X  swap              swap
> 
>    Why do I have a 16.4 MB /boot now?  I don't know.
> 
>    Now attempt to resize #5 to soak up the remaining free space
>    
>      "New partition size:" (max)
> 
>    Hmm, no change.  What is up here?  Is there some rule that a given
>    partition can't have more than a certain number of blocks, so the
>    smallest blocks allowed on partition #5 are 256MB?

No, it's just that partitions are only ever resized by moving the end of
the partition, not by moving the start. Using extra space before the
partition you're trying to resize would involve moving all the data on
the partition, which could break bootloaders expecting to find things at
particular offsets in the disk, cannot really be made resilient against
failures part-way through the process (at least not without lots of
extra free space to work with), and is generally a really bad idea.

> Let's start over: I select the disk and wipe its partition table.
> Then I manage to set up something like this, which looks like a start:
> 
>     IDE1 master (hda) - 30.0 GB
>       #1 primary      16.4 MB :-X ext3  /boot
>          pri/log       6.0 GB :-X fat32 /windows
>       #5 logical      24.0 GB :-X ext3  /  
>     LVM VG Ubuntu, LV root - 28.5 GB Unknown
>       #1 28.5 GB      :-X  ext3     /
>     LVM VG Ubuntu, LV swap_1 - 1.2 GB Unknown
>       #1  1.2 GB      :-X  swap     swap

Two root filesystems there. Exciting ...

> Hmm, after several failures for reasons I don't remember I am now
> able to create a logical volume.  I call it lv-var (I'm going to put
> /var there).  Works!  OK, now I want to create one for /var/log.  I
> call it lv-var/log.  Fails for cryptic reasons.  I switch to the 3rd
> console (which it's only just now telling me about!) to find some
> diagnostic info.  Nothing useful there at all; it just looks like the
> result of some command-line to which wrong options were supplied.  I
> figure it's the slash so I try again using lv-var-log.  Success! 

Mm, yes, definitely some extra validation needed there. This is:

  http://bugs.debian.org/254630

> So now I have a bunch of LVs in my own volume group, and then the two
> LVs set up by the installer are still hanging out there, apparently
> attached to the nonexistent (?) "Ubuntu" VG.  It's hard to imagine
> that it /really/ doesn't exist, because my previous install used just
> those two LVs and it seemed to work.  What does that mean?
> I guess I'm going to have to delete the ones that Ubuntu made for me (?)

Yes, the integration with partman here is really nasty and confusing.
:-(

> Seems to be working.  I'm wondering if this would have gone better had
> I called the VG I created "Ubuntu"?

I think it would work better if you deleted all the vestiges of the VGs
and LVs created by the autopartitioning tools before starting to create
your own. (I'm not going to try to defend this UI as being sensible,
though.)

Cheers,

-- 
Colin Watson                                       [cjwatson at ubuntu.com]