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Conference ssag::ask_ssag

Title:Ask the Storage Architecture Group
Notice:Check out our web page at http://www-starch.shr.dec.com
Moderator:SSAG::TERZAN
Created:Wed Oct 15 1986
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:6756
Total number of notes:25276

6355.0. "TZ877 & Random Access Mode" by RHETT::PARKER () Tue Jan 28 1997 13:57

    
    
    Hi Folks, 
    
    I've got a Digital customer using a TZ877 tape loader/changer
    and they are using a 3rd party backup/restore utility similar
    to NSR called alexandria. They are trying to use the TZ877 in
    random access mode. They say the way they used to be able to
    put it in that mode is with a key on the front panel. Now when
    they finish writing a tape, it goes on and loads the next tape
    as if it's in sequential access mode. 
    
    I have not worked with any of this so I'm just reporting what
    I was told. The 3rd party is SpectraLogic (sp?) and they are
    very interested in fixing this for our mutual customers. They
    wanted to try to contact the Product Manager to see if they
    could arrange for a loaner to do their development on for a
    short time. 
    
    Does anyone here have any ideas on either of these issues?
    
    Thanks in advance!!
    
    Lee
    
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6355.1Sequencial vs RandomSUBSYS::TRANStraight <Left> Hitter..Tue Jan 28 1997 14:0110
    
    Ah, the mixed mode will get you everytime!!!
    
    To fix this, don't issue UNLOAD to the drive after you done with the
    cartridge. Just send MOVE MEDIUM command to the loader (LUN 1) and the
    drive will automatically spindown and the arm will move the cartridge
    back to the source slot since you are using it in RANDOM mode.
    
    T.
    
6355.2NABETH::alanDr. File System's Home for Wayward Inodes.Tue Jan 28 1997 14:142
	The UNIX translation of "UNLOAD" in this case is "mt offline"
	or the MTOFFL op-code to the MTIOCTOP ioctl.
6355.3Thanks !!RHETT::PARKERTue Jan 28 1997 14:496
    
    Wow! Thank you both for the quick response!! I'll pass along
    the advice!
    
    Lee
    
6355.4They say...RHETT::PARKERThu Jan 30 1997 08:2415
    
    Hi All, 
    
    According to the customer - 
    
    We are deffinitely using the A5 command, move medium.
    
    Also, they say the way to place the TZ877 in random mode is to
    turn the key in the front of the device. Is this correct? Did
    something possibly change?
    
    Thanks again!
    
    Lee
    
6355.5More infoRHETT::PARKERThu Feb 06 1997 13:2827
    
    Hi Folks, 
    
    I got more information from the customer - apparently there are 2
    Digital customers now with this TZ877 issue. 
    
    What someone forgot to log is that they get an error
    in response to the MOVE MEDIUM command :
    
    It's logged in the alexandria log file :
    
    Status code = 0x02
    Sense Key = 0x05
    ASC = 0x3B
    ASCQ = 0x0D
    
    And, according to SpectraLogic, the key needs to be in
    the service position but the customer says that is needs
    to be in the locked or disabled position.
    
    Does anyone have any ideas on this one? I have never even seen
    a TZ877! ;-)
    
    Thanks for any suggestions!
    
    Lee
    
6355.6NABETH::alanDr. File System's Home for Wayward Inodes.Thu Feb 06 1997 14:2328
	Actually it looks like Alexandria tried to move a cartridge
	to a slot or drive that was already full, since that is what
	3B/0D means.

	The key lock has four positions:

		OCP (a lock icon)
		Disabled

			Automatic (four arrows making a box icon)
			Mode

			Manual (a hand grabbing something icon)
			Mode

		Service (a wrench icon)
		Mode

	Manual mode disables auto-loading of the next cartridge,
	but the manual I'm looking at (*) doesn't mention the affect
	any position has on Medium Changer commands.  If manual
	allows Medium Changer commands, Alexandria may expect that
	as the usual setting since it may disable AutoLoad on the
	TZ887 as well.  If Alexandria didn't expect AutoLoad to
	be on and it was, that would explain why they got a
	destination full.

	(*) DLT 4000 family product manual.
6355.7Thanks!!RHETT::PARKERThu Feb 06 1997 15:126
    
    Thanks Alan!! 
    
    I must have an older SCSI spec. - or at least I could not find 
    that combination of ASC/ASCQ's in mine... 
    
6355.8NABETH::alanDr. File System's Home for Wayward Inodes.Thu Feb 06 1997 19:075
	Try: http://scsiexdv.com/SCSI2/SCSI2-D.html.  This is Annex D
	of the 10L draft of the SCSI-2 spec.  It has all the standard
	ASC/ASCQ values for all devices types (at the time it was
	written).  It also happens that 10L was the draft approved
	as the real SCSI-2, with some editorial changes, of course.