Look on powerlink for this document:

Technical Guidance for Upgrades to EMC NetWorker 7.4
Service Pack 2

Your answers will be in there, along with others. 

Specificially:
Note: The features described in this section only apply for NetWorker
versions 7.3.x and above. You would still be able to backup and recover
data from older client versions (7.2.x and older) using a NetWorker 7.4
SP 2 server, but without the benefits provided by the new features (such
as new authentication). Please refer to:
http://solutions.emc.com/emcsolutionview.asp?id=esg83215 for more
information.

Technically, 7.4 client on 7.2 server isn't supported, but does work (at
least most of the time). 

David M. Browning Jr.
IT Project Coordinator Enterprise Backups and Help Desk
 
 
-----Original Message-----
From: EMC NetWorker discussion [mailto:NETWORKER AT LISTSERV.TEMPLE DOT EDU] On
Behalf Of Valdis Kletnieks
Sent: Thursday, May 22, 2008 11:01 AM
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Subject: [Networker] NW 7.2->7.4 upgrade - clients...

So I inherited a fairly large (300 clients backing up to an SL8500) 7.2
server, and we have some LTO-4 tape drives on order, which apparently
need 7.3.3 or later to support, so I may as well upgrade to "latest and
greatest".  I've got the media, the documentation, the licenses, and all
that.

I found a nice blurb about the auto-ambush client upgrade on page 45 of
the Install guide, and quickly dismissed that as a non-starter in our
environment.

What I *can't* find is any clear statement about client versus server
release levels - in particular:

1) If the server is at 7.2, will a 7.4 client work if they upgrade
first?
2) Once the client goes to 7.4, what's the oldest client that will still
be supported? I think I've got a few 7.1 clients still out there...

Any "you idiot, read page NN of the Foo Guide" replies would be greatly
appreciated... :)

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