<RANT>

I'll give my reasons for using the IBMtape driver... Simple fact of life...
the IBM LTO1 and LTO2 drives are probably going to run a little better with
an IBM driver.  Yeah, there are alternatives, but just because SUN and
Veritas might not support it doesn't mean IBM won't support it.  You're
already dealing with the Triple-headed hydra of support nightmares... I find
that it's easier to not try and avoid that when in the situation, but
embrace the monster and dance with it.  Might not be fun, but avoiding it is
just a dance of a slightly different kind.

Also, I have more than one library and server setup. I have a lot of
different ones. And I find the tapeutil utility that IBM provides to be the
best tool for the job when diagnosing problem drives and doing general
maintenance. Most of the libraries and servers I support are spread out
across the globe as part of my companies attempts to drive my bat-shit
insane. (At least I think that's the reason. Of course, they tell me they
have "business" reasons for it. I choose not to believe them.) So, being
able to remotely manage things is nice.  I know there are other tools to do
this... but they would then be spread across several different programs and
scripts -- and having them all in one place is nice.

And back to the support issue.  Being that I've been playing with tape
drives and backups and DR for sometime now, I know when the problem is
hardware, software, and the weird driver and firmware lands in-between most
of the time.  Most folks on this list probably have at least a general idea
what's wrong when things "break".  So, just because Veritas or Sun or IBM
says something is unsupported doesn't mean that that's the problem.  So,
I've learned to lie to vendors when I need too.  What they don't really need
to know doesn't hurt them -- half the time they're just asking mindless
questions while they fire up their search tool and think for a couple of
minutes anyway.

I know that a lot of this is the simple fact that I work for a large company
that has all the good support contracts and can  therefore get the vendors
too at least try to play nice amongst themselves.  Do I maybe abuse the
vendors? Maybe.  But then, that's what they're for, right?  :-)

</RANT>

------------------------------------
David N. Reiss          407-736-3912
david.reiss AT siemens DOT com
...one of God's own prototypes -- a high-powered mutant of some kind who was
never even considered for mass production. He was too weird to live and too
rare to die.

-----Original Message-----
From: Joost Mulders [mailto:mail AT j-mulders.demon DOT nl]
Sent: Friday, August 08, 2003 6:24 AM
To: Huslage.Aaron AT cnf DOT com
Cc: veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] LTO-1


>No reply anyone???
>How does the SG driver work? Doesn't it need to talk through the st driver
>to get its work done?

OK, I'll bite. 

No. 'sg' (SCSI generic) does not use 'st' (SCSI tape). sg attaches itself to

every HBA driver of the class scsi. sg is a pass thru driver: It allows 
userland applications to pass scsi commands to arbitrary scsi devices, just 
like Solaris' own USCSI interface.

IBMtape is a replacement for 'st'. So, even if you have IBMtape, you still 
need 'sg' for various purposes: serialization of devices and I believe that 
also reserve/release is done via 'sg'.

To rave on about the use of IBMtape: Why use it? 
 - VERITAS does not support it
 - SUN does not support it
 - You have trouble with it
What's the advantage of IBMtape over st?
 
SUN's policy is that there is 'st' support for every tape drive that SUN 
ships/resells with proper defaults (like variable block length). 

Sure there is support for LTO-1 and LTO-2 for IBM, HP and Seagate. Just 
install the latest 'st' patch for your OS and your set. There is really no 
need to modify st.conf if you have the latest 'st'. 

The current 'st' patches are:
 Solaris 2.6    105505-16
 Solaris 7      107461-14
 Solaris 8      108725-13
 Solaris 9      113277-12

Best regards, 

Joost
-- 
Long may you run.

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