Conference cookie::mru

303.0. "TL8x0 shared heterogeneous environment" by GOYA::GALAN () Wed Mar 19 1997 01:15

    
    
    Crossposted NETWORKER conference (note 501.*)
    
    As far as I know, the TL8x0 can be attached to a system using more
    than 1 bus, but we can not configure the TL in a SCSI cluster (NSR doesn't
    support the tape and changer devices on a shared bus)
    
    My question is about a heterogeneous environment, not cluster, so not a
    shared bus. Something like this:
                                 -------
                                | TL8xx |
                                |       |
              ------             -------                    -------- 
             |HP    |             | | |                    |DEC Unix| 
             |Unix  |             | | +--------------------|system  |   
             |system|-------------|-+                       --------
              ------              |  
                                  |     not shared bus
                                --------
                                | DEC  |
                                | WNT  |
                                 ------
      
      where each system can use the DLT tapes independently.
    
    Maybe one of the system can centralise the dialog to the TL8xx for
    mounting, labeling the tape, and then each system could use its own bus
    to do the backup.
    
    - Will Digital have any solution to this?
    - Does anybody know any third-party solution, maybe using our TL8x0
    robot?
    
    Thanks,Ana Galan.
    PreSales Technical Support 
    
    
    
    

	As long as you avoid a shared bus, you could control the
	robot from a single system.  MRU doesn't offer an RPC
	based API, but you could run CLI or GUI on one of the
	systems (Digital UNIX) and serve the display or terminal
	emulator running the CLI back to either of the other two
	systems.  HP will probably support rsh, which would allow
	running CLI commands remotely, with suitable permissions
	or feeding each command a password.

	The real problem with this is moving the tape OUT of the
	tape drives.  The TL820 and TL810 family won't allow the
	SCSI Move Medium command to work until the tape drives
	receieve a SCSI UNLOAD command (as opposed to the MRU
	unload command).  From the two UNIX systems this would
	an "mt offline".  Windows NT probably has its own way.  
	This complicates the coordination needed to move tapes
	around.  And obviously, there is nothing built-in to help.

	The Networker solution would be to run one of the systems
	as a server and then put the client software on each of
	the others.  If network bandwidth is an issue, get a faster
	network between the systems.  All three should support FDDI
	and maybe Fast Ethernet.  This doesn't solve the problem
	of general tape access though.

    
    OpenVision claims to support this environment. Check with them.
    However, we can not claim support until we test it.
    
    T.