Upgrading within a major version
It is usually safe to upgrade within a major version over the same data. Here's how:
1. Unless you already have a complete backup, backup all databases with:
mysqldump -uUSR -pPWD -K -E -A -R -f >some_backup_dir/mysqlbakVERSION.sqlsubstituting your values for
USR, PWD and VERSION. If mysqldump reports errors, fix them and repeat.
2. Stop the server
3. Upgrade MySQL in place
4. Restart the server with --skip-grant-tables to disable privilege checking
5. Run mysql_upgrade
6. Restart the server normally, ie without --skip-grant-tables
Upgrading across major versions
For upgrades across major versions, MySQL recommends that for each major version jump, you do a complete backup with mysqldump, then restore that copy of your databases into a new folder for the new installation. Here is a safe sequence:
1. Substituting your values for USR, PWD and VERSION, backup all databases with:
mysqldump -uUSR -pPWD -K -E -A -R -f >some_backup_dir/mysqlbakVERSION.sqlIf you are upgrading to 5.7.2 or later, add
--skip_flush_privileges to the above command. If mysqldump reports errors, fix them and repeat.
2. Stop the server
3. Install the next version
4. Restart the server with --skip-grant-tables
5. Reload the dump file using the source command in the mysql client
6. Run mysql_upgrade
7. Restart the server normally, ie without --skip-grant-tables
8. Test thoroughly, and fix any issues before proceeding to the next version
When things go awry, a useful diagnostic trick is to run ...
dmesg -T | grep mysqland look for words like "debied", "fail", "error".
There is a MySQL document about one-step upgrade from 5.0 to 5.6: http://mysqlserverteam.com/upgrading-directly-from-mysql-5-0-to-5-6-with-mysqldump/
Last updated 16 Aug 2019
