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Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/btrfs-man5.asciidoc | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/Documentation/btrfs-man5.asciidoc b/Documentation/btrfs-man5.asciidoc index 367736ce..b20abf05 100644 --- a/Documentation/btrfs-man5.asciidoc +++ b/Documentation/btrfs-man5.asciidoc @@ -14,9 +14,11 @@ tools. Currently covers: 2. filesystem features -3. file attributes +3. filesystem limits -4. control device +4. file attributes + +5. control device MOUNT OPTIONS @@ -608,6 +610,40 @@ the filesystem contains or contained a raid56 profile of block groups + reduced-size metadata for extent references, saves a few percent of metadata + +FILESYSTEM LIMITS +----------------- + +maximum file name length:: +255 + +maximum symlink target length:: +depends on the 'nodesize' value, for 4k it's 3949 bytes, for larger nodesize +it's 4095 ++ +The symlink target may not be a valid path, ie the path name components +can exceed the limits, there's no content validation at `symlink`(3) creation. + +maximum number of inodes:: +2^64^ but depends on the available metadata space as the inodes are created +dynamically + +inode numbers:: +minimum number: 256 (for subvolumes), regular files and directories: 257 + +maximum file length:: +inherent limit of btrfs is 2^64^ (16 EiB) but the linux VFS limit is 2^63^ (8 EiB) + +maximum number of subvolumes:: +2^64^ but depends on the available metadata space, the space consumed by all +subvolume metadata includes bookeeping of the shared extents can be large (MiB, +GiB) + +maximum number of hardlinks of a file in a directory:: +65536 when the `extref` feature is turned on during mkfs (default), roughly +100 otherwise + + FILE ATTRIBUTES --------------- The btrfs filesystem supports setting the following file attributes using the |