Migrating MySQL 5.0.x to 5.1.x

[Kevin J. Cummings]

I just upgraded my F10 server to F11.  [long story, it was via a
preupgrade to F13, and somehow *some* F11 packages got installed instead
of F13, but my rpmfusion stuff got upgraded to rawhide, and my atrpms
got upgraded to F13 and F12!  so I fixed those and finished the package
upgrades from what was left as fc10 packages by hand.]

I've fixed up most of what got broken, except for MySQL.
It won't start.  I've re-installed the RPMs (mysql, mysql-libs,
mysql-server) numerous times to no avail.

> # service mysqld start
> MySQL Daemon failed to start.
> Starting MySQL:                                            [FAILED]

Here is what appears in /var/log/mysqld.log

> 100520 00:11:05 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
> 100520  0:11:05 [Note] Plugin 'ndbcluster' is disabled.
> /usr/libexec/mysqld: Table 'mysql.plugin' doesn't exist
> 100520  0:11:05 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
> 100520  0:11:05  InnoDB: Started; log sequence number 0 13634811
> 100520  0:11:05 [ERROR] Fatal error: Can't open and lock privilege tables: Incorrect key file for table 'host'; try to repair it
> 100520 00:11:05 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended

I've tried to run mysql_upgrade as the log suggests, but it won't run if
mysqld isn't running.   B^/

I've Googled the "Table 'mysql.plugin' doesn't exist" error and the
results say that the bug got fixed in 2007 or 2008, so I am confused as
to how to migrate my data bases from 5.0.x to 5.1.x....

Did anyone else run into this?  And if so, how did you get around it?
I didn't see anything in the F11 release notes....

AFAICT, my old databases are still intact, I supposed I could
"downgrade" back to the fc10 MySQL stuff in order to dump the database,
then upgrade and restore from the dump, but there has got to be an
easier way, isn't there?

I know I can install from scratch (I did so on an F13 test system), but
I need to migrate my data base intact.

-- 
Kevin J. Cummings
kjchome at rcn.com
cummings at kjchome.homeip.net
cummings at kjc386.framingham.ma.us
Registered Linux User #1232 (http://counter.li.org)