Looks like this bug/inconsistency has been fixed, at least for the time being.
Just to clarify my previous observation… Prior to the fix, when installing root (/) into an Ext4 formatted LUKS partition, the system recognized the LUKS device as /dev/dm-0, rather than as /dev/mapper/sdaX_crypt. The are various ways that this could be observed. However, the easiest way to see this is by looking at sysmon. See U1604-2016-02-03.png, which is a screenshot showing sysmon running on a system installed using the U1604 daily build from 2016-02-03. And here’s what can be observed after installing with a more recent daily build… After the fix, when installing root (/) into an Ext4 formatted LUKS partition, the system recognizes the LUKS device as /dev/mapper/sdaX_crypt. See U1604-2016-02-26.png, which is a screenshot showing sysmon running on a system installed using the U1604 daily build from 2016-02-26. I’ll just add… This bug/inconsistency seems to have been unique to installing root (/) into an Ext4 formatted LUKS partitions. When installing root (/) into a BTRFS formatted LUKS partition, the system recognized the LUKS device as /dev/mapper/sdaX_crypt, both before and after the fix. Similarly, when installing root (/) into an XFS formatted LUKS partition, the system recognized the LUKS device as /dev/mapper/sdaX_crypt, both before and after the fix. Don’t know who submitted the fix, or if this report had anything to do with it, but thanks! ** Attachment added: "U1604-2016-02-03.png" https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1531387/+attachment/4583141/+files/U1604-2016-02-03.png -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1531387 Title: U1604: Installing root (/) into an Ext4 formatted LUKS partition creates /dev/dm-0, rather than /dev/mapper/sdaX_crypt To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1531387/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs