Guided LVM allows trying to large LV's with crash

[Anton Hvornum]

When going through the ubuntu-server guided installation.
I created a manual partitioning scheme. One disk for / and /boot and one external drive for /home. The /home partition was a LVM DMcrypt combination where I used default sizes suggested by the paritioner throughout the whole process.

The partition scheme can be seen here: https://hvornum.se/20200512_002718.jpg
It crashes here: https://hvornum.se/20200512_002750.jpg without showing me any options for a log which is probably the first issue, the installer just hard-crash and resets to the beginning.

Here's all the debug files I managed to scramble up: https://hvornum.se/debug.log.tar.gz (also attached here in the ticket)

The gist of it is: "Volume group "vg0" has insufficient free space (238455 extents): 238463 required"

(I've created a separate issue for the fact that the debug log contains my disk (dmcrypt) password)

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The solution would be to verify the size discrepancy between the PV's and the LV's sizes. And not allow for a maximum partition size in the GUI and then do a pvresize after the encrypted volume is created to the maximum allowed size fits.

[Michael Hudson-Doyle (mwhudson)]

Hmm. We allow 16 MiB as overhead for the luks header, but it seems that we still try to make a LV that's ~32 MiB too big. That's quite a way off! I wonder if the defaults changed in focal?