Syncing Servers

[jjones]

This following was asked by a friend of mine. Does anyone have any suggestions?

We are looking into migrating our main enterprise system, from Risc6000
AIX, to a linux server.

What we are looking to set up is, 3 linux servers (identical hardware
setup), these servers will need to be
setup as a cluster (so if one goes down, the other will automatically
take over).

2 of the servers would be sitting side by side on premise. 1 of the
servers would be offsite.

The 2 servers on site would be syncing constantly, so as mentioned, if
one failed, it would automatically switch over
to the 2nd server and we would be able to continue working....

the 3rd off-site server, we would not need it to sync constantly, but we
would want it to sync regularly, perhaps twice a day,
so if our premise became un-accessable, we could move to the offsite
one, and it would be relatively up-to-date, and we could
continue to function with minimumal interuption.

How difficult would it be to setup the above scenario?, what flavour of
linux would you recommend?

At this moment, we are just investigating the feasability of such a
setup. Your input would be appreciated.

[richiefrich]

You can do that with any linux.. All you need to do is run
rsync -a /foo /newfoo

you can set it up in cron to do that when ever you like.

[gtmtnbiker98]

This is an interesting topic. How would you provide credentials for a remote transfer via a Cron job?

I mean, for example: rsync -avz administrator@192.168.1.35:home/*.* /home/administrator/Documents

When I run the above, I'm prompted for an administrator password for that user account. How could I automate this task, where the password is automatically passed and how can I achieve this using Cron?

I'm not very script savvy!

[jjones]

I think you would have to use key based authentication to do it gtmtnbiker98.

Richiefrich I just discovered rsync and have been reading up on that. Cron would be okay for the off site server that was only synced twice a day, but what about the other two that they want in constant sync. I there a way to do that with a config file, as I think a cron job running every 5 or 10 mins would eat up a lot of resources.

I was also reading about GFS. Any comments on that?

[mitto]

Yes, You should use key based authentication for remote server sync.