Re: Redundant FTP

What we do is have a cluster of 2 Red Hat ftp servers that have content
synced up via a central staging server.  Most of our content is purely
outgoing, so internal "authorized" users place content on the staging
server and it rsyncs new stuff out every 5 minutes to the FTP servers.
Incoming content from anonymous users is synced to the central server as
well and then back out to the front-facing FTP servers.  This avoids having
a single point of failure via SAN/NFS solutions - the content is local on
each box.  We use a third party load balancer/failover tool, Resonate
Central Dispatch, to manage the front end (the only non-free software
involved).  Can't speak to the radius part.

Through careful use of rsync options you can prevent collisions.  We looked
into clustering and whatnot but it was way too much overkill for what we
needed to do.  We're pumping out 160 GB/day and it's working fine for us.

Ernest




                                                                           
             Ole Michaelsen                                                
             <omic+wuftpd@fys.                                             
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> What is the best way to create a redundant ftp setup with dual Red Hat 8
> systems that synchronizes ftp data and authenticates against a radius
> server?

For a redunant setup you could place your ftp-data on shared storage,
for example on SAN - then put wuftpd under control of application
cluster software, running on both nodes.

Users connect to a service ip-address, which is on the active node. When
the node dies, the cluster software notices, and attaches the storage to
the standby-node, attaches the service ip-address, and (since wuftpd is
launched from inetd) lets users connect again.

I don't know of cluster software to Redhat Linux, but for Solaris, HPUX,
and AIX I would use Veritas Cluster Server from Veritas,
www.veritas.com.

By having shared storage you don't need to sync between the two
machines.

With regards to authentication against radius, then I guess you can make
PAM do that?

Sorry for being so unspecific. It sounds like an interesting project
you're doing, and I hope you'll share your experiences when you get
further.

Brgds

--
Ole Michaelsen, Darmstadt, Germany
http://www.fys.ku.dk/~omic