RE: any experience with backup solutions for servers in the dmz?

From: spiff (spiffat_private)
Date: Thu Jan 13 2000 - 15:20:07 PST

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    Been busy of late, sorry to drop into this mid-thread.
    
    In my experience, dmz machines need their own tape drives, one for every
    host. It's just a place where one can't afford to skimp. While the cost
    may become high in instances of massive www server-farms, I think the
    benefits outweigh the cost. Consider that these machines are in your DMZ
    and so on the drontline of any attack you may experience. Just as one
    would make a backup of these machines in a known good state (and this is
    one reason the host should have it's own tape drive/dvdrom/MO
    disk/cd-writer), before putting them online in production, so too should
    there be a minimized risk associated with each separate host. Even if they
    are load-balanced mirrors, each should have it's own internal
    backup. Consider the scenario where you have 10 hosts in a dmz all
    connected to a backup server on their subnet. If one of those hosts is
    compromised, the likelihood of the backup server and the other 9 hosts
    being compromised increases significantly. The added admin overhead of
    authentication and monitoring is considerably higher with a networked
    backup server. It's a case of doing things completely differently than SOP
    for internal network stuff. It is far simpler to have each host in a dmz
    with it's own backup system.
    
    spiff
    
    On Tue, 11 Jan 2000, James R Grinter wrote:
    
    > On Mon 10 Jan, 2000, "Ginsberg Rainer (QI/INF4) *" <Rainer.Ginsbergat_private> wrote:
    > >ADSM uses a TCP connection. The port is configurable, default 
    > >is 1500. TCP connections will be established from both sides. 
    > >First, the server tells the client to do the backup, then the 
    > >client opens another connection and sends all its data.
    > 
    > Here's my understanding of the current situation with ADSM (TSM).
    > 
    > As things stand you can't limit where an Admin user can log in from, 
    > the admin client makes a connection to the same port 1500.
    > 
    > Can someone get an admin client program/binary easily? Yes.
    > Can someone connect from your system as an Admin? Yes, if they know/can
    >  deduce a user and password
    > Can someone sit there guessing passwords for an Admin user? If you've
    >  not set an invalid signon limit.
    > Can an admin user wreak havoc upon your backups? Yes, if they get one
    >  with sufficient privileges.
    > 
    > You can stop an ADSM client (node) from being able to delete backup
    > data, though.  You've just got to hope that someone doesn't back up
    > enough sets of data to blow a whole in your data retention policies
    > (eg. Ten previous sets of files - make 10 backups of corrupted
    > datafiles) before you notice and get back your off-sites: oh, you'd
    > probably need to restore the database to match them too because it
    > would have dropped all the previous backups. I don't think there's
    > a way around that - talk with your site ADSM expert or try asking
    > the ADSM-users list.
    > 
    > (I expect there are similar issues with other backup products.)
    > 
    > I can think of a few approaches to tackling the above issues. Maybe a
    > second dedicated server which transfers its data, after the backup
    > window, directly to another server? Or export filesystems inwards
    > to a seperate partitioned network and backup from another node.
    > 
    > James.
    > 
    



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