Announcement

Announcement Module
Collapse
No announcement yet.

Mysql_upgrade memory use

Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • Mysql_upgrade memory use

    I need to run mysql_upgrade after an upgrade to 5.1. Our host shut down our server unexpectedly so I suspect it will do a repair on the databases. Will the my.cnf [myisamchk] variables apply? Can anyone reccomend some values for a server with 18 gigs of RAM. Any other suggestions for speeding up the process?

  • #2
    "I need to run mysql_upgrade after an upgrade to 5.1."

    From what version did you upgrade? My experience is that the gab between 4.1->5.0 is better crossed by dumping the data and reloaded.

    "Our host shut down our server unexpectedly so I suspect it will do a repair on the databases."

    This statement is not quite true. For InnoDB tables, repair is automatic (and normally quite fast). For MyISAM tables no checking/repairing is done unless you turn on a setting called "myisam_recover".

    I wouldn't recommend myisam_recover, since it will run through each of the tables one by one - and it's probably better to write your own script to do this.

    "Will the my.cnf [myisamchk] variables apply? Can anyone reccomend some values for a server with 18 gigs of RAM. Any other suggestions for speeding up the process?"

    Myisamchk is a program that should only be run when the server is shutdown.

    The manual pages you want to read are:
    http://dev.mysql.com/doc/refman/5.0/en/myisam-crash-recovery .html
    http://dev.mysql.com/doc/refman/5.0/...am-repair.html

    They describe most of the configuration changes that will speed up recovery. The only one they don't mention, is that recovery is probably going to be faster if the MyISAM tables are in a filesystem cache. You may want to try doing something like "cat mytable.MYD > /dev/null" and see if it produces any measurable difference.

    Comment

    Working...
    X