From 5eb10904fcc64bb5e421b6f7e6a907543a94fe3b Mon Sep 17 00:00:00 2001 From: Kern Sibbald Date: Mon, 6 Aug 2012 21:58:02 +0200 Subject: [PATCH] Update sparse documentation --- docs/manuals/en/main/fileset.tex | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/docs/manuals/en/main/fileset.tex b/docs/manuals/en/main/fileset.tex index 3d531564..3bf78b63 100644 --- a/docs/manuals/en/main/fileset.tex +++ b/docs/manuals/en/main/fileset.tex @@ -517,9 +517,9 @@ Change: 2005-11-06 12:36:48.000000000 +0100 ndbm. The default is {\bf no}, so no checks are made for sparse files. You may specify {\bf sparse=yes} even on files that are not sparse file. No harm will be done, but there will be a small additional overhead to - check for buffers of all zero, and a small additional amount of space on - the output archive will be used to save the seek address of each - non-zero record read. + check for buffers of all zero, and if there is a 32K block of all zeros + (see below), that block will become a hole in the file, which + may not be desirable if the original file was not a sparse file. {\bf Restrictions:} Bacula reads files in 32K buffers. If the whole buffer is zero, it will be treated as a sparse block and not written to @@ -547,6 +547,9 @@ Change: 2005-11-06 12:36:48.000000000 +0100 benchmark the difference or set sparse for only those files that are really sparse. + You probably should not use this option on files or raw disk devices + that are not really sparse files (i.e. have holes in them). + \label{readfifo} \item [readfifo=yes\vb{}no] \index[dir]{readfifo} -- 2.39.2