From the dmesg output:
total RAM covered: 4014M
Memory: 3862760K/4087216K
CPU0: Intel(R) Core(TM) i5-3210M CPU @ 2.50GHz
Ubuntu Server's minimum requirements are 1G, but this install looks like it has desktop elements (libreoffice, etc.) 4G is a bit on the lower side of the system requirements for Ubuntu Desktop, perhaps the upgrade process hit a resource limit that made mysql take longer than usual to shutdown?
From the dmesg output:
total RAM covered: 4014M
Memory: 3862760K/4087216K
CPU0: Intel(R) Core(TM) i5-3210M CPU @ 2.50GHz
Ubuntu Server's minimum requirements are 1G, but this install looks like it has desktop elements (libreoffice, etc.) 4G is a bit on the lower side of the system requirements for Ubuntu Desktop, perhaps the upgrade process hit a resource limit that made mysql take longer than usual to shutdown?