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Conference turris::digital_unix

Title:	DIGITAL UNIX(FORMERLY KNOWN AS DEC OSF/1)
Notice:	Welcome to the Digital UNIX Conference
Moderator:	SMURF::DENHAM

Created:	Thu Mar 16 1995
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	10068
Total number of notes:	35879

9901.0. "TZ887 multivolumn on unix 4.0 possible?" by HGOM22::DAVYSUN () Wed May 21 1997 05:40

    Hi,
    
    As we all know,TZ887  can be used as multivolume to backup data on
    
    Openvms without loading the  tapes in it one by oe manully.
    
    But on DIgital Unix , when we are using tar,How to reliaze to tar a big 
    
    file into multivolume while the TZ887 knows to load the tapes one by
    
    one automatically?
    
    
    
    Thank you in  advance!
    
    Davy

T.R	Title	User	Personal Name	Date	Lines
9901.1		SSDEVO::ROLLOW	Dr. File System's Home for Wayward Inodes.	`Wed May 21 1997 10:42`	28
	You give the TZ887 more credit than it is due. There is a class of medium changers with the semi-feature of loading the next tape in a "magazine" when the drive receieves a SCSI Unload command. The TZ887 is one of these medium changers. If OpenVMS behaves as you suggest, it is probably because BACKUP sends the necessary Unload command (). The ULTRIX versions of tar, dump and I think even dd had this feature of sending an Unload (or equivalent) for selected drives, but the feature seems to have been removed from Digital UNIX. What you want to do is: a. Develop a way of running tar (dump, cpio, etc) so that it can intercept the "please load next tape" message to use "mt offline" to load the next tape for you. b. Beat up on the product managers to get the feature put back. I don't think it is something that should be done blindly, since I've seen the grief this can cause other applications. c. Buy/use a backup product that will take advantage of the feature. () I'm pretty sure this is the case, because the semi- feature causes considable grief in a managed media system layered on top of BACKUP.
9901.2	ftp.kar.dec.com/GNU/tar-1.12.tar.gz	KAMPUS::NEIDECKER	EUROMEDIA: Distributed Multimedia Archives	`Fri May 23 1997 04:45`	4
	While I haven't tried it with our TZ887, using GNU tar with the --multivolume and --new-volume-script options should be able to do what you want (and it doesn't have any problems with files larger than 2 Gbyte).