[DRBD-user] Questions

[Helmut Wollmersdorfer]

crisen at tiscali.co.uk schrieb:

 > Q1: Do you mean install all (OS and applications) identically on both 
machines
 > and then configure DRBD, services?

Yes.

 > Or can I install all on one and just
 > the OS on the second, put in DRBD on both, configure the services and see
 > all replicated to the second?


Theoretically, but this is complex.

 > I am starting from scratch.


You can put the harddisk of the second machine into the first and clone 
the installation.

 > Q2: You mentioned heartbeat, and I see it's included in the 9.1 distro.
 > Is this to be installed and configured after DRDB but before the 
services?
 > Or last?


You can install, run and configure them independantly, but if they 
should work together, you should configure them together.

 > Q3: Is there a list somehwere? Apart from data, how do I know that on 
primary
 > fail, some essential service hasn't been left out from the secondary 
because
 > I did not include some directory on the primary for mirroring?


You will see it, because the service will not work. Then have a look in 
the logs.

There is no list, what to mirror or not. This depends on your needs, 
technical constraints, and capabilities of the services. E.g. in case of 
Apache someone wants the conf be identical, someone wants an other conf 
in an failover situation. Maybe you want to mirror the access.log, but 
not the error-log, maybe none, maybe both.

Helmut Wollmersdorfer