Re: Best way to migrate to new machine w/ min downtime.

Paul Watson wrote: > > Cosmo Lee wrote: > > > > I need to migrate a client from one machine to another. The problem is > > that the machine is online (pun intended) all of the time, so they can > > only afford a minimum of downtime. > > > cutting > > Depending on the hardware/software etc. have you considering just > replicating the systems. > > -- > Paul Watson > WF Software Ltd > Tel: +44 121 440 3179 > Fax: +44 121 440 3806 > Email: paulw@wfsoftware.co.uk As I wrote earlier, replication is not a good option, because replication requires the two systems to have identical chunk configurations. Part of our migration involves changing the layout of chunks because the original system was badly configured. Although, one of the strategies I'm considering is to implement replication, then altering the tables once we have the data copied over. This will require us to procure at least enough disk space to hold the equivalent of two copies of the entire databases for the duration of the table alterations. What that boils down to is having one set of disks, partitioned exactly like the original server, then another set with the desired partitioning. We mirror the original server on the first set of disks. Once the data is replicated, we bring the system online. Then we alter the tables to fragment to the desired chunks (on the second set of disks) to get the new partitioning. This way the downtime could at least be limited to a specific table for the duration of the alteration. Whew! It's not going to be pretty, but it's the only way I can figure of avoiding the downtime of migration using dbexport. Unless anybody has a better idea??? -- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Blah Blah Lounge - "Do You Have Something Smart To Say?" Cosmo Lee email: cosmo@echonyc.com Brooklyn, NY * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *