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Re: Cygrunsrv and backups
"Craveiro, Marco" wrote:
>
> "Don Sharp" wrote:
>
> > > anyway, there's just one thing i dont understand on your script:
> > >
> > > mt -f /dev/nst0 tell
> > >
> > > why do you need this?
> > >
> >
> > One doesn't strictly need it. I use it to tell me how near to a full
> > tape I am using so I reshuffle what goes on which tape when it proves
> > necessary.
> >
> hey, that is quite cool as I want to add 2 tests to my script (is
> the tape full, is the tape empty). how do i interpret the tell output, i.e.
> whats the max blocks on a compressed dds-2 tape?
The initial
mt -f /dev/nst0 status
reports
tape capacity : 1760887 KB remaining : 1760887 KB
current block : 0 write protected :
no datcompression : on
Note the tape capacity report. This is NOT a constant as bad blocks are
removed from the capacity automatically. The tape is a DDS-1 of
nominally 2Gb capacity.
The tape blocks reported by "tell" depends on the blocking set before.
In my case because I am using default tar blocking it reports in 10K
blocks. However I have noticed that if I run an NT backup beforehand,
"tell" reports in 1K blocks. I believe that you can set the block size
for the hardware using "mt".
HTH
Don Sharp
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