I had spent a few hours on this with no resolution.  Even with the mysql
service running as root, it failed to get permissions to write to a data
directory other than /var/lib/mysql (or whatever the default is if that's
wrong).  Even with apparmor configured to allow the new data directory, and
even in complain mode, it still failed to read/write files in the new
datadir or couldn't open a socket.

My fix was moving my data to the location; mounting a device to
/var/lib/mysql.

On Tue, Jun 21, 2016 at 11:43 AM, Mitch Claborn <email address hidden>
wrote:

> Re: [Workaround Option 3/3]
>
> I tried this method, placing my local customizations in
> /etc/mysql/mysql.conf.d/local.cnf but mysqld did not pick those up. I
> had to name my file zzlocal.cnf. I'm guessing it reads those file in
> alpha order, with the later files overriding the earlier.
>
> --
> You received this bug notification because you are subscribed to a
> duplicate bug report (1573878).
> https://bugs.launchpad.net/bugs/1571865
>
> Title:
>   mysql fails to start after upgrade if previous defaults were
>   customised
>
> Status in Release Notes for Ubuntu:
>   Fix Released
> Status in mysql-5.7 package in Ubuntu:
>   In Progress
> Status in mysql-5.7 source package in Xenial:
>   Triaged
>
> Bug description:
>   In 14.04 (both in 5.5 and 5.6), the default /etc/mysql/my.cnf shipped
>   with options "key-buffer" and "myisam-recover". In 5.7, these option
>   names have been removed and replaced with "key-buffer-size" and
>   "myisam-recover-options" instead. If a user customised
>   /etc/mysql/my.cnf before, then the entire file is preserved, including
>   the removed options, causing mysqld to fail to start after upgrade to
>   5.7 (eg. when upgrading to 16.04).
>
>   If your customisations were made in 15.04 or 15.10 and
>   /etc/mysql/my.cnf.migrated does not exist, then the workarounds below
>   are still essentially the same but with a couple of exceptions:
>
>   1. Instead of editing /etc/mysql/my.cnf.migrated, edit the file you
>   originally changed directly. This may be /etc/mysql/my.cnf (through
>   the symlink), or a file you changed or added in either
>   /etc/mysql/conf.d/ or /etc/mysql/mysql.conf.d/. The command "grep -Er
>   'key.buffer|myisam.recover' /etc/mysql" may help you in locating this.
>
>   2. No need to run update-alternatives to remove use of
>   /etc/mysql/my.cnf.migrated.
>
>   [Workaround Option 1/3]
>
>   To reset your MySQL configuration back to defaults, type "sudo update-
>   alternatives --remove my.cnf /etc/mysql/my.cnf.migrated" after the
>   upgrade. Then use "sudo service mysql start" to start the MySQL daemon
>   and "sudo apt-get -f install" to recover your system packaging state.
>
>   This option is not available if /etc/mysql/my.cnf.migrated doesn't
>   exist on your system, for example if your customisations were made on
>   15.04 or 15.10.
>
>   [Workaround Option 2/3]
>
>   For a quick fix while retaining your existing customised
>   configuration, edit the [mysqld] section /etc/mysql/my.cnf.migrated as
>   follows. But see the caveats detailed below and consider Workaround
>   Option 3/3 instead first.
>
>   1. Replace "key_buffer" with "key_buffer_size". Note that there is a
>   second occurrance of "key_buffer" under the [isamchk] section at the
>   end of the file; changing this second occurrance is not necessary.
>
>   2. Replace "myisam-recover" with "myisam-recover-options".
>
>   Then use "sudo service mysql start" to start the MySQL daemon again
>   and "sudo apt-get -f install" to recover your system packaging state.
>
>   However, this workaround does not put you in the best place for future
>   upgrades, since packaging will continue to not be able to perfectly
>   update this file while preserving your modifications. Additionally
>   there may be parts of your previously customised configuration that
>   still will not work with MySQL 5.7.
>
>   To make future upgrades smoother in the future, consider following the
>   next workaround option instead.
>
>   [Workaround Option 3/3]
>
>   Examine /etc/mysql/my.cnf.migrated for the customisations you made
>   previously. You can find an original version of /etc/mysql/my.cnf as
>   shipped with 14.04 at: http://bazaar.launchpad.net/~ubuntu-
>
> branches/ubuntu/trusty/mysql-5.5/trusty/view/head:/debian/additions/my.cnf
>
>   Determine the changes you made to /etc/mysql/my.cnf. Taking only these
>   changes and not the default contents of this file, add just your
>   customisations into a new file at /etc/mysql/mysql.conf.d/local.cnf
>   (preferred) and/or by editing /etc/mysql/mysql.conf.d/mysqld.cnf (to
>   be avoided if possible) if necessary.
>
>   Run: "sudo update-alternatives --remove my.cnf
>   /etc/mysql/my.cnf.migrated" to switch to the new configuration scheme.
>
>   Run: "sudo service mysql start" to start the MySQL daemon and "sudo
>   apt-get -f install" to recover your system packaging state.
>
>   [Original Description]
>
>   Upgrading from 15.10 to 16.04 fails here
>   Not sure if this is related to a bug report already reported.
>
>   ProblemType: Package
>   DistroRelease: Ubuntu 16.04
>   Package: mysql-server-5.7 5.7.11-0ubuntu6
>   ProcVersionSignature: Ubuntu 3.19.0-30.34-generic 3.19.8-ckt6
>   Uname: Linux 3.19.0-30-generic x86_64
>   ApportVersion: 2.20.1-0ubuntu2
>   Architecture: amd64
>   Date: Mon Apr 18 18:13:33 2016
>   ErrorMessage: subprocess installed post-installation script returned
> error exit status 1
>   InstallationDate: Installed on 2014-04-18 (731 days ago)
>   InstallationMedia:
>
>   Logs.var.log.daemon.log:
>
>   MySQLConf.etc.mysql.conf.d.mysql.cnf: [mysql]
>   MySQLConf.etc.mysql.conf.d.mysqld_safe_syslog.cnf:
>    [mysqld_safe]
>    syslog
>   MySQLConf.etc.mysql.conf.d.mysqldump.cnf:
>    [mysqldump]
>    quick
>    quote-names
>    max_allowed_packet   = 16M
>   MySQLConf.etc.mysql.mysql.conf.d.mysqld_safe_syslog.cnf:
>    [mysqld_safe]
>    syslog
>   MySQLVarLibDirListing: ['debian-5.7.flag', 'debian-5.5.flag',
> 'debian-5.6.flag', 'ib_logfile1', 'drupal8', 'servermail', 'ib_logfile0',
> 'auto.cnf', 'risenlif_risenlife2', 'dynazu_wiki', 'performance_schema',
> 'ibdata1', 'phpmyadmin', 'ib_buffer_pool', 'mysql_upgrade_info',
> 'parke_wiki', 'tracker', 'mysql']
>   ProcCmdline: root=LABEL=DOROOT ro
>   RelatedPackageVersions:
>    dpkg 1.18.4ubuntu1
>    apt  1.2.10ubuntu1
>   SourcePackage: mysql-5.7
>   Title: package mysql-server-5.7 5.7.11-0ubuntu6 failed to
> install/upgrade: subprocess installed post-installation script returned
> error exit status 1
>   UpgradeStatus: Upgraded to xenial on 2016-04-18 (0 days ago)
>
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>