Tag: sql

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OpenStack Nova Essex MySQL Database Schema Diagram and SQL

I’m in the process of setting up an OpenStack Essex installation on a small cluster of Ubuntu 12.04 servers using the Canonical-supplied and supported packages. I innocently and unfortunately ended up with a state corruption issue causing nova-compute to crash on startup, and found it necessary to dive into the schema as a troubleshooting aid. I used MySQL workbench to reverse-engineer the schema into an EER diagram as well as raw SQL. I’m sure others will find this useful as the OpenStack community slowly upgrades to Essex. Hope it helps!

[Download diagram, SQL, and MySQL workbench file]

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computer

MacPort MySQL “Can’t find file: ‘./mysql/host.frm'” Error

I recently set up a new Mac OS X Snow Leopard laptop for software development purposes. After going through my usual MacPorts installation and installed MySQL using the following steps

  1. sudo install mysql5-server
  2. sudo cp /opt/local/var/macports/software/mysql5/5.1.44_0/opt/local/share/mysql5/mysql/my-medium.cnf /opt/local/etc/mysql5/my.cnf
  3. sudo -u mysql mysql_install_db5
  4. sudo launchctl load -w /Library/LaunchDaemons/org.macports.mysql5.plist

A few days past, and one day I notice that launchctl was loading the script, but `nmap localhost` did not show the the process listening on port 3306 as expected. I looked at the log file:

sudo tail -f /opt/local/var/db/mysql5/preston.local.err

..and noticed it was terminating with the following errors:

100331 12:05:30 [ERROR] /opt/local/libexec/mysqld: Can’t find file: ‘./mysql/host.frm’ (errno: 13)
100331 12:05:30 [ERROR] Fatal error: Can’t open and lock privilege tables: Can’t find file: ‘./mysql/host.frm’ (errno: 13)

100331 12:05:30 [ERROR] /opt/local/libexec/mysqld: Can’t find file: ‘./mysql/host.frm’ (errno: 13)100331 12:05:30 [ERROR] Fatal error: Can’t open and lock privilege tables: Can’t find file: ‘./mysql/host.frm’ (errno: 13)

After a considerable amount of grief I evertually discovered that the contents of /opt/local/var/db/mysql5/ need to be owned by the appropriate mysql user (in my case “_mysql”), but some files were being owned by the “root” user. After correcting all file ownership and restarting the service…

  1. sudo chown -R _mysql /opt/local/var/db/mysql5/
  2. sudo launchctl unload -w /Library/LaunchDaemons/org.macports.mysql5.plist
  3. sudo launchctl load -w /Library/LaunchDaemons/org.macports.mysql5.plist

Everything now seems to work fine again. Hope this helps!