Mirroring a server

[Dre G.]

On Tue, 2004-01-27 at 12:01, Brian Kelsay wrote:
> >The only problem with rsync is it can't run in a dameon mode & it can't tell when files have 
> >changed. I'd like to have something that would run in the background & sync's the files as
> >soon as they change.
> 
> On Tue, Jan 27, 2004 at 07:39:36AM -0600, Brian Kelsay wrote:
> > Jason Crowe wrote:
> > 
> > >How can I keep the two servers mirrored after they are put into use? I 
> > >had planned on using dd after the install. is using cat a better way?
> > >
> > >Thanks,
> > >Jason
> > >
> > 
> > man rsync, over ssh?
> 
> For a basic deal you could use cron to have it sync.  You may end up needing a second NIC to 
carry the sync load to the backup server.  If you just wanted a backup, I just read some 
interesting stuff on Mondo in Linux Journal.  It looks like a pretty good backup utility.  As 
Charles said, if you want auto failover and HA then you need to look further.  The simple fact that 
you are asking and not implementing, means you are probably not ready for HA or clustering or other 
complicated means.   I know I'm not.  Try something simple to start with to get your project off 
the ground and go complicated later.  You may be able to use your old mail server temporarily as 
the backup until the 2nd highend server is ready.  Just a thought.
> 
> Brian Kelsay
> 
> 
> 
> 

I currently use rsync over ssh, its simple and very effective. As others
have already pointed out, nicing it is very good because of the fact
that it will hammer the cpu for all its worth if you do not.

I in fact just back up whole mysql dbs as well (as they sit on the disk
being in read write mode at the time) and have never had a problem
putting things back even after full blow disk failures.

Example

A long time ago I was really dumb. I had my domain running on a stripe
setup. I did however have this backup policy. The stripe broke. I
installed the base OS and a few of the services and then just rsynced
back ALOT of things people think wont work, like read write databases,
etc etc etc... basically the whole server. I did this rebooted and it
worked wonderfully well. This has also worked to restore mysqldbs that
are mistakenly removed as well! yay!

I hope this input helps..

-- 

Dre G. <enabled at linuxjunkies.com>