Comment 2 for bug 1475247

In another stuck install, looks like sgdisk eventually moves on:

2015-07-16 15:11:33 INFO mon-relation-changed ^MReading state information... 0%^M^MReading state information... 0%^M^MReading state information... Done
2015-07-16 15:11:33 INFO mon-relation-changed ^GCaution: invalid backup GPT header, but valid main header; regenerating
2015-07-16 15:11:33 INFO mon-relation-changed backup header from main header.
2015-07-16 15:11:33 INFO mon-relation-changed
2015-07-16 15:11:33 INFO mon-relation-changed Warning! Main and backup partition tables differ! Use the 'c' and 'e' options
2015-07-16 15:11:33 INFO mon-relation-changed on the recovery & transformation menu to examine the two tables.
2015-07-16 15:11:33 INFO mon-relation-changed
2015-07-16 15:11:33 INFO mon-relation-changed Warning! One or more CRCs don't match. You should repair the disk!
2015-07-16 15:11:33 INFO mon-relation-changed
2015-07-16 15:55:33 INFO mon-relation-changed ^G^G****************************************************************************
2015-07-16 15:55:33 INFO mon-relation-changed Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk
2015-07-16 15:55:33 INFO mon-relation-changed verification and recovery are STRONGLY recommended.
2015-07-16 15:55:33 INFO mon-relation-changed ****************************************************************************
2015-07-16 15:55:33 INFO mon-relation-changed GPT data structures destroyed! You may now partition the disk using fdisk or
2015-07-16 15:55:33 INFO mon-relation-changed other utilities.
2015-07-16 15:55:33 INFO mon-relation-changed The operation has completed successfully.

Look at the delta between the "repair the disk" advice and the last line. That would account for sgdisk in D state doing stuff to the disk. What, I don't know.

This disk in particular, /dev/sdb, is a:
[ 3.913915] sd 0:0:1:0: [sdb] 5860533168 512-byte logical blocks: (3.00 TB/2.72 TiB)