MySQL rightly says you should dump and reload. As William said, you should read the release notes for every release between your current release and the target release.
I have done this several times. I am currently planning a migration from 4.1.22 to 5.1.49 with a brief stop at 5.0 along the way. There is almost 200 gigs of data on the master server in this situation so it does take some foresight and planning. However, the end result will be no significant downtime. You can configure MySQL 5.0 as a slave of MySQL 4.1 so you might consider doing that. That way when its time for the actual upgrade you just point the application to the MySQL 5.0 server and shut down the MySQL 4.1 server (which CANNOT be a slave of MysQL 5.0 -- it's a one way relationship due to the changes in the binary logging. Hope that helps. keith On Mon, Aug 16, 2010 at 11:42 AM, Wm Mussatto <mussa...@csz.com> wrote: > > > On Mon, August 16, 2010 07:26, Nunzio Daveri wrote: > > Hi all, I > was reading a few of the notes on this forum from a few months > > > back > > and it seems that ONE WAY of upgrading from 4.x to 5.X with > MyISAM only > > databases is to copy the actual data folder from the > 4.X version to a temp > > place, then remove 4.x from the OS, > install 5.X and then just put the 4.X > > data > > folder into > the 5.X folder??? > > > > > > Is it really that > simple? Has anyone done this and can verify this > > please? I > > am thinking I am missing a few commands you have to run at least??? > My > > database > > is pretty small is an only 1.8GB so I am > thinking this is a walk in the > > park :-) > > > > > Please advise... > > > > And as always... TIA... > > > > > Nunzio > What version of 4.x, I upgraded between > Debian stable versions and got burned because in the middle of the 4.x > group MySQL changed to a more "correct" version of JOINs. > Didn't effect to data, which will should work as you expect, but did have > subtle impact on the select statements embedded in various programs. > Read the release note between YOUR current and new versions. > ------ > William R. Mussatto > Systems Engineer > http://www.csz.com > 909-920-9154 > -- Chief Training Officer Paragon Consulting Services 850-637-3877
