[clue] 32 bit app, 64 bit OS

[rjohnston at denverinternet.com]

 On May 25, 2012 at 8:44 AM grant thus quoth :

> I am wondering the pitfalls of running 32 bit applications on 64 bit Linux.
>
> We are looking at upgrading a large enterprise system.   It would be
> very helpful if we could upgrade the operating system first, because
> then we can upgrade the application in place and carry over all of our
> settings and data more easily.   The old version is a 32 bit
> application, the new one is a 64 bit application.   If we upgrade the
> hardware and operating system first, this is better, since it is due a
> hardware upgrade anyway, and we are looking at maybe moving it to a
> new data center.   We would like to run this way for a while, then do
> the upgrade, since it is a large project to upgrade this mess.  Where
> is this going to bite us?


something big like this is actually benefited by upgrading the hardware as well.
 when possible, I like to set up my new, install and test the 64bit os, and turn
it into my staging server.  if it's a db -  send my transaction logs to it, and
run both in parallel and at some point make the new into the live.

the largest unknown is most likely the new 64 app - because it is really a low
level re-write, rather than an upgrade.
so I approach them as a migration. and hopefully someone has tested
compatibility already, but I prepare a backout plan just in case.

...r