Amanda-Users

Re: Different tapetypes

2005-04-01 14:19:45
Subject: Re: Different tapetypes
From: Gene Heskett <gene.heskett AT verizon DOT net>
To: amanda-users AT amanda DOT org, erik AT epo DOT dk
Date: Fri, 01 Apr 2005 14:14:06 -0500
On Friday 01 April 2005 13:49, Erik P. Olsen wrote:
>On Fri, 2005-04-01 at 13:09 -0500, Gene Heskett wrote:
>> On Friday 01 April 2005 03:19, Erik P. Olsen wrote:
[...]
>Last year I had head crash with my two 60 GB disks when they where
> still under warranty. I had them replaced but couldn't wait the 3
> weeks it took, so I had to buy new ones. Last time it happened
> (there were 6 months in between) the tape streamer also died and
> took the tape with it. I'm sure Murphy has a law for that. As a
> consequence I could not restore the system even with a new and well
> functioning tape station in place. Statistically this problem
> should never occur, but it did.
>
And you weren't taunting the happy fun ball?  :-)

>> > It worked extremely
>> > well, if I crashed my system - which I did very often - it took
>> > me about half an hour to recover either using a stand-alone
>> > recover program or my maintenance OS/2 if it was alive and I
>> > kept an archive of up to 8 weeks of back-ups.
>>
>> I was always told that OS2 was stable.  And I stay quite bleeding
>> edge in terms of the kernel I run on this FC2 system, which is
>> also backing up my RH7.3 firewall box.  Currently running
>> 2.6.12-rc1, the smoothest running, snappiest kernel yet in the 2.6
>> series.  I can't recall the last time I actually crashed a running
>> system.  Several months ago in any event.
>
>OS/2 is stable though not as stable as FC3. The frequent crashes
> were mainly because I did a lot of testing with new system
> software.

So do I, new firewire movie camera & a pcHDTV-3000 card.
Which I might add is working flawlessly witu 2.6.12-rc1, but nothing 
later in the mm or realtime pipelines.

>> > Now with Linux and Amanda I
>> > use 9 tapes mainly because Amanda won't add today's back-up to
>> > yesterday's tape.
>>
>> Thats a security risk amanda won't take.  When amanda is done, and
>> has released the drive, there is nothing to prevent someone from
>> removing the tape, and either reinserting it, in which case the
>> tape is rewound and will be totally overwritten, or even the wrong
>> tape might be reloaded.  Either way, amanda has no ironclad
>> assurance that the tape will be sitting in the same position it
>> was left in, ready to append new files to it.  Yes, most drives
>> today can do an 'mt -d/dev/nst0 seof' and hit within a quarter of
>> an inch of it.  But some drives cannot, and that locks amanda out
>> of useing that feature for all users.  At some point, the last
>> legacy drive that cannot do that might die, but we have no idea
>> when that might be...
>
>I suppose the back-up software placed a sort of end-of-tape mark
> after each back-up and just searched for that tapemark when a new
> back-up was about to be run. I've used it for 5 years and it never
> failed. It would even ask for another tape to continue the back-up
> if the first tape ran full.

It does, and it works flawlessly for me with any of the many DDS2 
drives I've had.  However, when that command became generally 
available, I don't know.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
99.34% setiathome rank, not too shabby for a WV hillbilly
Yahoo.com and AOL/TW attorneys please note, additions to the above
message by Gene Heskett are:
Copyright 2005 by Maurice Eugene Heskett, all rights reserved.

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