[SATLUG] Simple fail-over options

[Channing.ML]

Samuel Leon wrote:
> I need to get redundancy on a business webserver.  Not really sure how 
> to go about this.  First I got to figure out the best way to keep the 
> 2 servers synced.  And then I was thinking about maybe writing a bash 
> script on server#2 or something that would ping server#1 every minute 
> or so.  Then if the ping times out, it will run another script to 
> change its IP to server#1's IP.  Seems like it would work as long as 
> server#1 is truly down and doesn't come back to life and we end up 
> with 2 of the same IP's on the same network.  Sound good or alittle 
> too dirty?
>
>
> Sam
Regarding file-system synchronizing, here is a tool that I read about 
some time back, but have not had a chance to use yet.  It's based on 
rsync, but targets those needs such as you have described.

http://blog.kowalczyk.info/articles/usingUnison.html

There are also tools such as drdb & enbd which are designed to mirror 
filesystems across a network (think RAID 1 via TCP/IP).

HTH,
Channing