Conference turris::digital_unix

Digital recommends DLT as the primary backup media, DAT is NOT considered
to be a backup media for critical enterprise solutions. 

That beeing said, here are some answers (applicable for DLT & DAT tape loaders): 

1. You also need SCSI CAM Layered Components for Digital UNIX (CLC)

2. Networker *requires* CLC to operate the tape loader

3. No. If you are not using Networker, you'll need the Media Robot Utility (MRU)
   (SPD 64.44.01) to license CLC since CLC is only licensed together with 
   an application that's using it. 

Regards, 

Arnold

    .1 still misses one very important item. Except for NSR there is no
    software that will AUTOMATICALLY use a tape loader device to change
    tape.
    
    If you do a dump or vdump which is longer that one tape I do not
    believe the CLC or media robot utility can do the tape switch.
    

	re: .-1

	If you're doing the backup interactively, you can use mt(1)
	to force a tape change remotely; mt offline.  You can use
	MRU as well.  The problem is that dump and vdump are written 
	to be strictly interactive and expect that an operator is 
	present to intervene when a tape change is needed.

	The annoying part about this is that the ULTRIX version of
	dump would do sequential tape changes when it knew that it
	could.  The problem was that it had to know what all the
	sequential loaders were because the driver couldn't just
	tell it.  The Digital UNIX tape drives have access to just
	the feature that ULTRIX needed and for some devices it even
	works, but nothing takes advantage of it.

	If the customer needs automated backups, then NSR should be
	the first choice.  The potential problem, is that NSR takes
	over the loader and you have to very careful using it for
	other things.  If you don't interact with its media manager
	properly when you want to use the drive, you may find NSR
	trying to write on your data tapes.  You might do well to
	get a 2nd tape drive so you can have one for backups and one
	for data.

    
    Arnold, Ron & Rollow,
    
    Thank you for your replies.
    
    Points noted -
    -  DLT preferable to DAT
    -  MRU (with CLC can handle the tape drive) but not really useful 
       to write continuously on to multiple tapes.
    -  NSR is the only software that can really facilitate taking 
       advantage of the tape loader.
    
    I have a question for Rollow (as I have not used NSR). Can you 
    please let me know some more on "NSR takes over the loader" and 
    "one for backups and one for data".
    
    Are you suggesting something like have a tape loader dedicated to 
    NSR & have one single tape drive for other ad-hoc backups ?
    
    A general question -
    where can I get the docs for CLC & MRU ?
    
    Thanks in advance.
    
    Nandan

	NetWorker (aka NSR) expects access to any defined drive at all
	times.  If system dumps are taken using other tools like
	tar, dd, or dump, it is safer to send them to another drive.
	
	Using DLT for the primary backups with NetWorker and a TLZ06 or
	other DAT drive for a periodic system dump works very well.
	On a small system like a private desktop, stopping NetWorker
	once every week or two, changing tapes, and making the system
	dump is an alternative.  What ever method is used, the more care
	taken in the backups the quicker the system will be back in
	operation after a failure.

   
>Note 9406.1 
>ZUR01::SUTTER "Who are you ??? - I'm BATMAN !!!"    
>               -< Use DLT, not DAT as serious backup device ... >-
>----------------------------------------------------------------------------
>Digital recommends DLT as the primary backup media, DAT is NOT considered
>to be a backup media for critical enterprise solutions. 


	While I agree with you in general, I have never seen this 
	message in any material coming from Storage, certainly not
	in the product anouncement for the TLZ9L RDAT drive.

	Do you have a reference to where "Digital" makes this statement?

	The MRU kits are on:

		nabeth.cxo.dec.com:StorageWorks/ROBOT*.tar.Z
			   nabeth::StorageWorks/ROBOT*.tar.Z

	ROBOT120 is the field test kit.  ROBOT110 is the current
	kit.  If you don't see a .Z version of the archive, it
	means it got larger when compressed or wasn't enough
	smaller to mess to copies.  The archive expands to a
	documentation directory and kit directory.  You can point
	setld at the kit directory for an installation.  All the
	MRU and CLC documentation is included in the documentation
	directory.  The Software Library CDROM will also have the
	current CLC kit with its documentation.

	The CLC kit on the V1.1 MRU kit has a bug in it, but the
	T1.2 kit has the current CLC kit (V3.1A).

    
    Roger & Alan,
    
    Thanks for your response & the information.
    
    I have the kit with me. Alan, what I meant is do you get more info then
    the Install Guides & Release Notes that come with the kits, or is there
    more documentation available somewhere else.
    
    For example, are 'man' pages all that are available about MRU & CLC ?
    
    Thanks in advance.
    
    Nandan

	The installation guide, manual pages and GUI help files are all 
	the documentation that is available for MRU.  As manual pages
	go, we're told by an early field test site that the API manual
	pages in T1.2 are quite good.  The CDROM version of the kit
	and perhaps the documentation directory has an HTML version of
	the guide.

	We tried to keep the documentation thin so it wouldn't over-
	burden the boxes that the tape drives or their documentation
	come in.  If you have specific questions or suggestions on
	the MRU documentation, you can put them in our VAXnotes
	conference which is at COOKIE::MRU or send mail to:

		[email protected]

    
    Rollow,
    
    Thank you for the information.
    
    Nandan

>>Note 9406.1 
>>ZUR01::SUTTER "Who are you ??? - I'm BATMAN !!!"    
>>               -< Use DLT, not DAT as serious backup device ... >-
>>----------------------------------------------------------------------------
>>Digital recommends DLT as the primary backup media, DAT is NOT considered
>>to be a backup media for critical enterprise solutions.


>	While I agree with you in general, I have never seen this 
>	message in any material coming from Storage, certainly not
>	in the product anouncement for the TLZ9L RDAT drive.
>
>	Do you have a reference to where "Digital" makes this statement?

I don't think you'll find anything official from Storage in this regard. 

I was just trying to pass over my experiences with DAT drives where I've 
seen many of them generating problems over time here in MCS land. On the
other hand, I have seen very few problems with DLT tapes/drives.