David Mathog wrote:

> In order to keep a streaming tape streaming it must be fed data at a
> very high rate of speed. When that data is coming from a remote system
> that's generally impossible to do unless a program like Lee McLoughlin's
> "buffer" is used. The thing is, buffer only allows a maximum buffer of
> around 16Mb. I've found that with an SDLT320 that only ends up
> streaming the drive for a few seconds, for instance like this (linux
> system with tape drive, remote linux, same sort of thing if remote
> is Solaris):
>
> ssh root@$REMOTE "dump -0 -q -B 2000000000 -f - -u $TPARTITION | gzip
> -3 -c" <dev/null 2>>$BLOG | \
> buffer -m 16384k -p 75 -B -o /dev/nst0 2>>$BLOG
>
> What I'm looking for is a program that can buffer to two disk files of
> say 1G each, filling one while writing the other to tape.
> Probably these should be on two different disks. Anyway, the idea
> is that when the buffer file is filled it can easily stream the full
> 1Gb to tape. The tape spends much more time streaming, and much, much
> less time rewinding and waiting - which wears both the drive and the
> tape. If a 16M buffer results in 5 seconds of streaming then a 1Gb
> buffer file should be around 5 minutes of streaming.
>
> The question is - is there such a program around already? I've googled
> but keywards like "file" and "buffer" are so common that it's hard to
> find anything.
>
> Thanks,
>
> David Mathog

How did you wind up with a tape drive that needs a higher data rate than
your system can supply? Given what tape drives, especially high
performance tape drives, cost it seems like a waste of money. If you
manage to provide a gigabyte buffer, your tape drive will stream for
five minutes, sit idle for X minutes, stream for five minutes. . . .

Or am I missing something?