From b681e2536ec8f03a7d25de68f52ddd03ca5de845 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 26 Jun 2015 16:23:00 +0200 Subject: btrfs-progs: doc: update defrag page - update wording for -t - add optional argument to -c Signed-off-by: David Sterba --- Documentation/btrfs-filesystem.asciidoc | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'Documentation') diff --git a/Documentation/btrfs-filesystem.asciidoc b/Documentation/btrfs-filesystem.asciidoc index 26c3fbc..31cd51b 100644 --- a/Documentation/btrfs-filesystem.asciidoc +++ b/Documentation/btrfs-filesystem.asciidoc @@ -49,27 +49,32 @@ Defragment file data and/or directory metadata *online*. If '-r' is passed, files in dir will be defragmented recursively. The start position and the number of bytes to defragment can be specified by start and len using '-s' and '-l' options below. -Any extent bigger than threshold given by '-t' option, will be considered -already defragged. -Use 0 to take the kernel default. +Extents bigger than value given by '-t' will be skipped, otherwise this value +is used as a target extent size, but is only advisory and may not be reached +if the free space is too fragmented. +Use 0 to take the kernel default, which is 256kB but may change in the future. You can also turn on compression in defragment operations. + `Options` + -v:::: be verbose --c:::: -compress file contents while defragmenting +-c[]:::: +compress file contents while defragmenting. Optional argument selects the compression +algorithm, 'zlib' (default) or 'lzo'. Currently it's not possible to select no +compression. -r:::: -defragment files recursively +defragment files recursively in given directories -f:::: -flush filesystem after defragmenting +flush data for each file before going to the next file. This will limit the amount +of dirty data to current file, otherwise the amount cumulates from several files +and may increase system load. -s [kKmMgGtTpPeE]:::: defragment only from byte onward -l [kKmMgGtTpPeE]:::: defragment only up to bytes -t [kKmMgGtTpPeE]:::: -defragment only files at least bytes big +target extent size, do not touch extents bigger than + For , , it is possible to append units designator: \'K', \'M', \'G', \'T', \'P', or \'E', which represent -- cgit v1.2.1