tape (sa0) on sparc64 ?

[Matthias Andree]

Am 17.05.2013 02:56, schrieb Zaphod Beeblebrox:
> On Thu, May 16, 2013 at 8:30 PM, Greg 'groggy' Lehey <grog at freebsd.org>wrote:
> 
>> On Thursday, 16 May 2013 at 19:56:14 -0400, Zaphod Beeblebrox wrote:
>>> On Thu, May 16, 2013 at 5:08 PM, Bob Bishop <rb at gid.co.uk> wrote:
>>>> On 16 May 2013, at 21:51, Zaphod Beeblebrox wrote:
>>>>
>>
>>
> [about my tape drive not working]
> 
> 
>> The obvious question: can you write tapes and read them back?  My
>> experience with DDS tapes was of extreme unreliability.  The age
>> doesn't make things any easier.
>>
> 
>  Well... therein lies my other suspicion.  I don't have any DDS4 tapes to
> try writing, but the DDS3 tapes I have fail to write.
> 
> ... but they don't even try.  The tape spools up when inserted and "mt
> offl" works (ejects the tape) and the drive doesn't indicate any error at
> this point --- but it doesn't even try to start moving for either read or
> write.

Have you used dd, tar, or pax, to actually write data?  I suppose newer
DDS drives would not actually engage the tape to their head drum until
you were actually reading/writing, in order to reduce wear and tear of
tape and heads.

Not that it helps you now:

Personally, after a few first steps with DDS1DC and DDS2, I dropped
helical scan stuff because I often found that I could read tapes only on
the same drive that had written them (I had three drives around in the
late 1990s/early 2000); no matter if the heads were cleaned or not, and
I moved on going for for optical disks and linear tape (which includues
MLR/SLR, DLT, SuperDLT, LTO; personally I used SLR2, SLR4DC and SLR6 aka
SLR24).