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).
[Impact]
Server will fail to start, causing upgrade/installation of MySQL to fail.
[Test case]
1. Install mysql-server in Ubuntu Trusty
2. Edit /etc/mysql/my.cnf and save it (can just add a comment)
3. Upgrade distro to Xenial
Expected behavior:
Server upgrades and starts normally
Actual behavior:
Server fails to upgrade, because it can't start, throwing an error about 'unknown option key_buffer'
[Regression Potential]
* If the sed command is faulty in some way it could mangle the options,
leading to the server not starting and installation failing
[Workarounds]
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/zzlocal.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)
From log:
2016-04-
2016-04-
2016-04-
2016-04-
2016-04-
2016-04-
2016-04-
2016-04-
2016-04-
2016-04-
2016-04-