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Diffstat (limited to 'Documentation/btrfs-filesystem.asciidoc')
-rw-r--r-- | Documentation/btrfs-filesystem.asciidoc | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/Documentation/btrfs-filesystem.asciidoc b/Documentation/btrfs-filesystem.asciidoc index dc032faa..9782af9b 100644 --- a/Documentation/btrfs-filesystem.asciidoc +++ b/Documentation/btrfs-filesystem.asciidoc @@ -11,9 +11,10 @@ SYNOPSIS DESCRIPTION ----------- -*btrfs filesystem* is used to do the whole filesystem level tasks, including -all the regular filesystem operations like resizing, space stats, label -setting/getting, and defragmentation. +*btrfs filesystem* is used to perform several whole filesystem level tasks, +including all the regular filesystem operations like resizing, space stats, +label setting/getting, and defragmentation. There are other whole filesystem +taks like scrub or balance that are grouped in separate commands. SUBCOMMAND ---------- @@ -116,15 +117,23 @@ compression. See also section 'EXAMPLES'. -r:::: defragment files recursively in given directories -f:::: -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. +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 will increase system load. This can also lead +to ENOSPC if there's too much dirty data to write and it's not possible to make +the reservations for the new data (ie. how the COW design works). ++ -s <start>[kKmMgGtTpPeE]:::: defragmentation will start from the given offset, default is beginning of a file -l <len>[kKmMgGtTpPeE]:::: defragment only up to 'len' bytes, default is the file size -t <size>[kKmMgGtTpPeE]:::: -target extent size, do not touch extents bigger than 'size' +target extent size, do not touch extents bigger than 'size', default: 32M ++ +The value is only advisory and the final size of the extents may differ, +depending on the state of the free space and fragmentation or other internal +logic. Reasonable values are from tens to hundreds of megabytes. *du* [options] <path> [<path>..]:: Calculate disk usage of the target files using FIEMAP. For individual |