Re: File System Performance

Alan Cox
2001-11-12T22:33:04Z

> Corrections to speed-up the sizeing pass in Amanda:
> * tar.h: Declare dev_null_output.
> * buffer.c (open_archive): Detect when archive is /dev/null.
> (flush_write): Avoid writing to /dev/null.
> * create.c (dump_file): Do not open file if archive is being
> written to /dev/null, nor read file nor restore times.
> Reported by Greg Maples and Tor Lillqvist.
>
> One wonders why.

So when you archive the file set twice (once to compute its size) its
faster. Seems sane enough.