The kernel was unable to re-read the partition table on /dev/md0 (Invalid argument).

インストール時のSoftware RAID構成で、下記の警告が発生。
原因不明だが、インストール後は問題ないようなので、しばらく様子見。

"The kernel was unable to re-read the partition table on /dev/md0 (Invalid argument).
This means Linux won't know anything about the modifications you made until you reboot.
You should reboot your computer before doing anything with /dev/md0."