A file with the ’t’ attribute will not have a partial block fragment at the end of the file merged with other files (for those filesystems which support tail-merging). This is necessary for applications such as LILO which read the filesystem directly, and which don’t understand tail-merged files. Note: As of this writing, the ext2 or ext3 filesystems do not (yet, except in very experimental patches) support tail-merging.
When a file with the ‘u’ attribute set is deleted, its contents are saved. This allows the user to ask for its undeletion. Note: please make sure to read the bugs and limitations section at the end of this document.
The ’X’ attribute is used by the experimental compression patches to indicate that a raw contents of a compressed file can be accessed directly. It currently may not be set or reset using chattr(1), although it can be dis- played by lsattr(1).
The ’Z’ attribute is used by the experimental compression patches to indicate a compressed file is dirty. It may not be set or reset using chattr(1), although it can be displayed by lsattr(1).
AUTHOR
chattr was written by Remy Card <Remy.Card@linux.org>. It is currently being maintained by Theodore Ts’o
<tytso@alum.mit.edu>.
BUGS AND LIMITATIONS
The ‘c’, ’s’, and ‘u’ attributes are not honored by the ext2 and ext3 filesystems as implemented in the current
mainline Linux kernels. These attributes may be implemented in future versions of the ext2 and ext3 filesys-
tems.
The ‘j’ option is only useful if the filesystem is mounted as ext3.
The ‘D’ option is only useful on Linux kernel 2.5.19 and later.
AVAILABILITY
chattr is part of the e2fsprogs package and is available from
SEE ALSO
lsattr(1)
E2fsprogs version 1.41.12 May 2010 CHATTR(1)