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Diffstat (limited to 'doc/guix.texi')
| -rw-r--r-- | doc/guix.texi | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index f38e018dff..92ea87d6b7 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -12348,17 +12348,23 @@ server socket is open and the signing key has been read. @item --compression[=@var{method}[:@var{level}]] @itemx -C [@var{method}[:@var{level}]] Compress data using the given @var{method} and @var{level}. @var{method} is -one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip} -is used. +one of @code{lzip}, @code{zstd}, and @code{gzip}; when @var{method} is +omitted, @code{gzip} is used. When @var{level} is zero, disable compression. The range 1 to 9 corresponds to different compression levels: 1 is the fastest, and 9 is the best (CPU-intensive). The default is 3. -Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small -increase in CPU usage; see -@uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web -page}. +Usually, @code{lzip} compresses noticeably better than @code{gzip} for a +small increase in CPU usage; see +@uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip +Web page}. However, @code{lzip} achieves low decompression throughput +(on the order of 50@tie{}MiB/s on modern hardware), which can be a +bottleneck for someone who downloads over a fast network connection. + +The compression ratio of @code{zstd} is between that of @code{lzip} and +that of @code{gzip}; its main advantage is a +@uref{https://facebook.github.io/zstd/,high decompression speed}. Unless @option{--cache} is used, compression occurs on the fly and the compressed streams are not @@ -15400,7 +15406,9 @@ at level 7 and gzip at level 9, write: @end lisp Level 9 achieves the best compression ratio at the expense of increased CPU -usage, whereas level 1 achieves fast compression. +usage, whereas level 1 achieves fast compression. @xref{Invoking guix +publish}, for more information on the available compression methods and +the tradeoffs involved. An empty list disables compression altogether. |