Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

We are about to upgrade our MySQL boxes from 5.1 to 5.5 and because of the size, would prefer to do this as an in-place upgrade. Are there any issues with this? From my research, I noticed that the MySQL manuals for 5.0 and 5.1 mention that they are ok, but the 5.5 manual recommends a dump/restore. I've seen on blogs, for instance, vague responses of "I've had problems..." but nothing specific.

Has anyone done this and have had success or failure? For reference, I'm on RH 5. Thanks! -Dave

(Note: Not sure if this belongs here or DB Admins but I see more similar questions here )

share|improve this question
up vote 2 down vote accepted

As a MySQL DBA, I have never trusted mysql_upgrade. The Achilles' heel of moving data from one release of MySQL to a higher release of MySQL is the risk of messing up the tables in the mysql schema. The best thing you can do is dump all databases except information_schema database (mysqldump ignores that by default) and the mysql database.

How can one safely migrate the MySQL user permissions from an old mysql instance to a new one ???

I have done that way for years and I would never recommend otherwise.

Give it a Try !!!

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.