[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

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

9770.0. "USE OF TLZ7L-VA ON DEC-UNIX V3.2G" by WARFUT::MELLING () Sun May 11 1997 08:18

    
    	Is it possible to use the TLZ7L-VA unit with the 12 cassette
    	magazine without the use of DECNSR.
    
    	I have a customer trying to use the device,working ok with
    	the 4 cassette magazine but unable to access the 5'th cassette
    	when the 12 slot magazine is used.
        The error returned is just to the dump command and nothing
    	is in the system errorlog.
    	
    	Is it necessary to use mt to allow the device driver to gather
    	information relating to a 12 cassette magazine being in use.
    
    
    	regards
    
    tony melling

T.R	Title	User	Personal Name	Date	Lines
9770.1		SSDEVO::ROLLOW	Dr. File System's Home for Wayward Inodes.	`Sun May 11 1997 14:20`	27
	To the best of my knowledge none of the usual tape utilties released with current or past versions of Digital UNIX have support for media changers. For sequential changers, you can use the mt(1) command to take the drive "offline" and it will load the next tape if there is one. You either have to do this by hand, watching for dump wanting a next tape or have something that runs dump, intercepts the messages and recognizes the need for an offline command. A TLZ7L with any of the magazines available, should be able to work in this environment. In the case of 8 and 12 slot carriers you need to make sure there is clearance in front, above and below the carrier to for it move. The motor that moves the magazine isn't strong enough to lever the drive, if it happens to run into a desk or tabletop... It would help if you could provide a transcript of the error. It could have nothing to do with the larger magazine. I'm assuming that the TLZ7L doesn't include a feature where it handles EOT internally to load a "next" tape. If it did support such a feature, I would assume that it work no matter what number of slots were in the carrier. For random access to the slots you can use the Media Robot Utility. It won't automate your backups anymore than mt(1) does, but it give more control over which tapes to load.
9770.2		WARFUT::MELLING		`Mon May 12 1997 09:26`	21
	Hello, The customer is using mt to offline the currently loaded tape and cause the unit to load the next tape in the magazine. This seems to work ok when the 4 cassette magazine is in use,the customer tried to use the 12 cassette unit and on accessing the 5'th tape the backup log shows an " I/O ERROR " .Nothing though in the system errorlog. It talks in the spec over media initialisation commands to determine the size of the magzine in use. I was wondering if there is an MT command that is required to perform this. regards tony
9770.3		SSDEVO::ROLLOW	Dr. File System's Home for Wayward Inodes.	`Mon May 12 1997 11:10`	11
	I'll shortly be gone for a week, so don't be surprised if I don't offer any more hints. Is the mt(1) failing with an I/O error or the dump? My experience with mt(1) is that when a tape takes "too long" to load, mt(1) will fail. I don't recall if this causes logged I/O errors or not. If dump is getting the I/O error, it could be similar timing problem. If the tape isn't loaded when dump tries to open the drive, it could fail as well. This points to a tape problem more than a magazine problem.