Dear Maintainer,

   * What led up to the situation?

Installing on a Sony Vaio Z2 which has a (fake) raid (intel matrix) disk.

When I create partitions on /dev/dm126 (the raid0 volume) the partition table
is updated but the /dev entries are not created.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

Created (secondary) partitions for my /boot and / filesstems

   * What was the outcome of this action?

The partition table was updated but the corresponding /dev entries weren't created

   * What outcome did you expect instead?

/dev entries (e.g. /dev/md126p5) to be created reflecting the change to the
partition table.

(Workaround:  Create the partition table entries, reboot, the /dev/ entries
are created as the partition tables are read).