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

Cosmo Lee <cosmo@echonyc.com> 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. : :My thought is that I need to run a level 0 archive, load that onto the :new machine, then just before we're ready to cut over, take the old :machine offline, bring the logs over from the old machine to the new :machine, roll them forward on the new machine, then bring the new :machine online. This would work if the versions of OnLine are exactly (or very near) the same and the machines and OS are similar enough. :My concern is that certain utilites seem to be chunk or page specific. :The new machine will not have the same partitioning as the old machine. :So I need to avoid any utilities which would rely on such specifics. Is there any reason why you can't set up the machines to be initially equivalent. You do use symbolic links so even if the disks/device drivers aren't exactly the same it should be doable. :Which backup utility would be best in such a case? I believe that :Ontape is not usable because it tries to restore to the same device, :(these will be different on the new machine) correct? Unload and :Dbexport don't keep logs after running, so I can't do a roll-forward. :Is OnArchive the choice in this scenario??? I don't know OnArchive very well, but judging from the problems people have had it may not be a good option. I don't know if it can restore to different dbspaces. One other idea *might* be to set up replication between the two machines. In that case you should be able to switch over with virtually no downtime at all. This of course requires fairly similar machines, OS and Informix versions as well. If they are too different you may be able to use the products from Praxis if they aren't too expensive for the purpose. Nils.Myklebust@idg.no NM Data AS, P.O.Box 9090 Gronland, N-0133 Oslo, Norway My opinions are those of my company The Informix FAQ is at http://www.iiug.org