I hit the following error shortly on entering the mysql "root" password:

An error occurred while setting the password for the MySQL administrative user. 

This may have happened because the account already has a password, or because of a

communication problem with the MySQL server.

Here is the full output of apt-get install mysql-server:

Reading package lists... Done

Building dependency tree       

Reading state information... Done

The following extra packages will be installed:

  libaio1 libdbd-mysql-perl libdbi-perl libmysqlclient18 libterm-readkey-perl

  mysql-client-5.5 mysql-client-core-5.5 mysql-common mysql-server-5.5

  mysql-server-core-5.5

Suggested packages:

  libclone-perl libmldbm-perl libnet-daemon-perl libplrpc-perl

  libsql-statement-perl tinyca mailx

The following NEW packages will be installed:

  libaio1 libdbd-mysql-perl libdbi-perl libmysqlclient18 libterm-readkey-perl

  mysql-client-5.5 mysql-client-core-5.5 mysql-common mysql-server

  mysql-server-5.5 mysql-server-core-5.5

0 upgraded, 11 newly installed, 0 to remove and 49 not upgraded.

Need to get 0 B/8,797 kB of archives.

After this operation, 93.5 MB of additional disk space will be used.

Do you want to continue? [Y/n] y

Preconfiguring packages ...

Selecting previously unselected package libaio1:i386.

(Reading database ... 88930 files and directories currently installed.)

Preparing to unpack .../libaio1_0.3.109-4_i386.deb ...

Unpacking libaio1:i386 (0.3.109-4) ...

Selecting previously unselected package mysql-common.

Preparing to unpack .../mysql-common_5.5.40-0ubuntu0.14.04.1_all.deb ...

Unpacking mysql-common (5.5.40-0ubuntu0.14.04.1) ...

Selecting previously unselected package libmysqlclient18:i386.

Preparing to unpack .../libmysqlclient18_5.5.40-0ubuntu0.14.04.1_i386.deb ...

Unpacking libmysqlclient18:i386 (5.5.40-0ubuntu0.14.04.1) ...

Selecting previously unselected package libdbi-perl.

Preparing to unpack .../libdbi-perl_1.630-1_i386.deb ...

Unpacking libdbi-perl (1.630-1) ...

Selecting previously unselected package libdbd-mysql-perl.

Preparing to unpack .../libdbd-mysql-perl_4.025-1_i386.deb ...

Unpacking libdbd-mysql-perl (4.025-1) ...

Selecting previously unselected package libterm-readkey-perl.

Preparing to unpack .../libterm-readkey-perl_2.31-1_i386.deb ...

Unpacking libterm-readkey-perl (2.31-1) ...

Selecting previously unselected package mysql-client-core-5.5.

Preparing to unpack .../mysql-client-core-5.5_5.5.40-0ubuntu0.14.04.1_i386.deb ...

Unpacking mysql-client-core-5.5 (5.5.40-0ubuntu0.14.04.1) ...

Selecting previously unselected package mysql-client-5.5.

Preparing to unpack .../mysql-client-5.5_5.5.40-0ubuntu0.14.04.1_i386.deb ...

Unpacking mysql-client-5.5 (5.5.40-0ubuntu0.14.04.1) ...

Selecting previously unselected package mysql-server-core-5.5.

Preparing to unpack .../mysql-server-core-5.5_5.5.40-0ubuntu0.14.04.1_i386.deb ...

Unpacking mysql-server-core-5.5 (5.5.40-0ubuntu0.14.04.1) ...

Processing triggers for man-db (2.6.7.1-1) ...

Setting up mysql-common (5.5.40-0ubuntu0.14.04.1) ...

Selecting previously unselected package mysql-server-5.5.

(Reading database ... 89293 files and directories currently installed.)

Preparing to unpack .../mysql-server-5.5_5.5.40-0ubuntu0.14.04.1_i386.deb ...

Unpacking mysql-server-5.5 (5.5.40-0ubuntu0.14.04.1) ...

Selecting previously unselected package mysql-server.

Preparing to unpack .../mysql-server_5.5.40-0ubuntu0.14.04.1_all.deb ...

Unpacking mysql-server (5.5.40-0ubuntu0.14.04.1) ...

Processing triggers for man-db (2.6.7.1-1) ...

Processing triggers for ureadahead (0.100.0-16) ...

Setting up libaio1:i386 (0.3.109-4) ...

Setting up libmysqlclient18:i386 (5.5.40-0ubuntu0.14.04.1) ...

Setting up libdbi-perl (1.630-1) ...

Setting up libdbd-mysql-perl (4.025-1) ...

Setting up libterm-readkey-perl (2.31-1) ...

Setting up mysql-client-core-5.5 (5.5.40-0ubuntu0.14.04.1) ...

Setting up mysql-client-5.5 (5.5.40-0ubuntu0.14.04.1) ...

Setting up mysql-server-core-5.5 (5.5.40-0ubuntu0.14.04.1) ...

Setting up mysql-server-5.5 (5.5.40-0ubuntu0.14.04.1) ...

141117 20:53:10 [Warning] Using unique option prefix key_buffer instead of key_buffer_size is deprecated and will be removed in a future release. Please use the full name instead.

start: Job failed to start

invoke-rc.d: initscript mysql, action "start" failed.

dpkg: error processing package mysql-server-5.5 (--configure):

 subprocess installed post-installation script returned error exit status 1

dpkg: dependency problems prevent configuration of mysql-server:

 mysql-server depends on mysql-server-5.5; however:

  Package mysql-server-5.5 is not configured yet.



dpkg: error processing package mysql-server (--configure):

 dependency problems - leaving unconfigured

Processing triggers for libc-bin (2.19-0ubuntu6.3) ...

No apport report written because the error message indicates its a followup error from a previous failure.

                                                                                                          Processing triggers for ureadahead (0.100.0-16) ...

Errors were encountered while processing:

 mysql-server-5.5

 mysql-server

E: Sub-process /usr/bin/dpkg returned an error code (1)

To completely uninstall mysql, I have run through the following steps:

sudo apt-get remove --purge mysql-server mysql-client mysql-common

sudo apt-get remove --purge mysql-server-core-5.5 mysql-client-core-5.5

sudo apt-get autoremove

sudo apt-get autoclean

sudo deluser mysql

sudo rm -rf /var/lib/mysql

sudo rm -rf /etc/mysql

This seems to completely remove everything, but subsequent installation attempts produce the same problem.

I have also set permissions on /tmp.

It may be of note that Postgres is installed on this machine, but from what I understand this should not be a problem.

Thanks in advance for any help/suggestions.