Date: Fri, 20 Sep 1996 09:26:17 +0000 From: Darius Moos <moos@degnet.baynet.de> To: Sean Kelly <kelly@fsl.noaa.gov> Cc: FreeBSD-questions <questions@freebsd.org> Subject: Re: SCSI Tape support ? Message-ID: <32426339.7C79@degnet.baynet.de> References: <199609192017.UAA10787@gatekeeper.fsl.noaa.gov>
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Sean Kelly wrote:
> >>>>> "Timothy P Layton, Sr " <tlayton@global-sol.com> writes:
> If you used a block size when you dumped, use it with restore:
> restore tbf 64 /dev/rst0
> > Also I am using a density of 61000 as an argument for the dump
> > command. I am assuming that this is the correct density for a 2 Gb
> > DAT tape ?
> I wouldn't use the density argument because it's intended to help dump
> find the end-of-tape on devices that don't indicate end-of-tape. But
> your HP DAT drive certainly can detect end-of-tape. So, use the B
> option to specify a huge number of blocks. Before I started using
> Amanda for dumps, I used this command:
> dump 0nubBf 64 999999 /dev/nrst0 <filesystem>
Wasting space on the tape here.
The default block-size for dump is 1024 and you cannot change it for
DAT-tapes. As Joerg Wunsch stated in a mail to this group a few weeks
ago, the option "b" specifies only the number of blocks that are
written at once on every write-attempt for a dump-record.
More interesting to you would be the option "B", that specifies the
length of the tape. So for a 2 GB tape you get the following value:
B := 2 [GB] / 1024 [bytes] = 1024 * 1024 * 1024 * 2 / 1024 [bytes]
= 2097152 [blocks of 1024 bytes]
This will give you the full capacity of the tape.
Just ignore the density-option.
Also check the mail-archive on this topic.
Darius Moos.
--
email: moos@degnet.baynet.de
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