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From: petri@ibr.cs.tu-bs.de (Stefan Petri)
Newsgroups: comp.unix.wizards
Subject: Re: Data Redundancy made simple
Keywords: amd - mount Dir eine
Message-ID: <1991Jun28.145910.16988@ibr.cs.tu-bs.de>
Date: 28 Jun 91 14:59:10 GMT
References: <992@bcstec.boeing.com> <1991Jun26.112529@cunix7.prime.com>
Reply-To: petri@ibr.cs.tu-bs.de (Stefan Petri)
Organization: TU Braunschweig, Informatik, Bueltenweg, Germany
Lines: 42

In article <1991Jun26.112529@cunix7.prime.com> jasonp@cunix7.prime.com (Jason Pascucci) writes:
>In article <992@bcstec.boeing.com>, ruben@bcstec.boeing.com (Reuben
>Wachtfogel) writes:
>|> I could store dual copies of these files on 2 seperate nodes and 
>|> code the application to perform all updates of
>|> these files on this MASTER node as well as a BACKUP MASTER node
>|> so that if the MASTER were vaporized, the BACKUP could be slipped
>|> in with minimal downtime.
>|> 
>|> My question is: 
>|> 	
>|>          'Is there some application transparent way to achieve
>|>           data redundancy in a unix network ?'
>|> 
>
>I haven't heard about anything which would do this for you,

But I have :

What you want is to have a look at rdist(1)

	rdist - remote file distribution program

To keep the contents of your Backup consistent with the Master, and 
at amd(8) to create replicated NFS-Servers for your Users/Clients

	amd - automatically mount file systems

rdist should be contained in any reasonable version of Unix, maybe its also
in the freed parts of the BSD-Sorces (I didnt check that).

Amd is the BSD4.4-Automounter, but it runs on a broad variety of Unix'es

It's operation principles are similar to Sun's automount, but is has more
capabilities, especially to configure Backup Servers that get automagically
used when the Master is down.

Rdist and amd together work like a charm for us since several month now.

amd is available from usc.edu in ~ftp/pub/amd .

S.P.