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Date: Sat, 01 Mar 2008 21:11:33 +0100
To: "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org>
From: "Martin Laabs" <martin.laabs@mailbox.tu-dresden.de>
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Subject: multi volume dump with gzip/crypt - solved
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Hi,

I solved the dump problem in a not very
clean way.
First I changed dumps behaviour to ignore
the SIGPIPE signal when the -P and -a option
is given. The problem with occured than was
the loss of data because of the race condition
between "write date to pipe" and "receive SIGPIPE".

I solved that problem with a script that
takes the data from the pipe of dump, compress
it and sends a dedicated SIGPIPE to the three
dump processes when the output volume is nealy full.
After that it flushs the rest out of the pipe to
avoid data loss.

Greetings,
  Martin L.