extattrctl(8)
NAME
extattrctl - manage UFS1 extended attributes
SYNOPSIS
extattrctl start path
extattrctl stop path
extattrctl initattr [-f] [-p path] attrsize attrfile
extattrctl showattr attrfile
extattrctl enable path attrnamespace attrname attrfile
extattrctl disable path attrnamespace attrname
DESCRIPTION
- The extattrctl utility is the management utility for extend
- ed attributes
over the UFS1 file system. It allows the starting and stop - ping of
extended attributes on a file system, as well as initializa - tion of
attribute backing files, and enabling and disabling of spe - cific extended
attributes on a file system. - The first argument on the command line indicates the opera
- tion to be performed. Operation must be one of the following:
- start path
- Start extended attribute support on the file system
- named using
path. The file system must be an UFS1 file system, - and the
UFS_EXTATTR kernel option must have been enabled. - stop path
- Stop extended attribute support on the file system
- named using
path. Extended attribute support must previously - have been
started. - initattr [-f] [-p path] attrsize attrfile
- Create and initialize a file to use as an attribute
- backing file.
You must specify a maximum per-inode size for the - attribute in
bytes in attrsize, as well as the file where the at - tribute will
be stored, using attrfile. - The -f argument may be used to indicate that it is
- alright to
overwrite an existing attribute backing file; other - wise, if the
target file exists, an error will be returned. - The -p path argument may be used to preallocate
- space for all
attributes rather than relying on sparse files to - conserve space.
This has the advantage of guaranteeing that space - will be available for attributes when they are written, prevent
- ing low disk
space conditions from denying attribute service. - This file should not exist before running initattr.
- showattr attrfile
- Show the attribute header values in the attribute
- file named by
attrfile. - enable path attrnamespace attrname attrfile
- Enable an attribute named attrname in the namespace
- attrnamespace
on the file system identified using path, and backed - by initialized attribute file attrfile. Available namespaces
- are "user"
and "system". The backing file must have been ini - tialized using
initattr before its first use. Attributes must have - been started
on the file system prior to the enabling of any at - tributes.
- disable path attrnamespace attrname
- Disable the attributed named attrname in namespace
- attrnamespace
on the file system identified by path. Available - namespaces are
"user" and "system". The file system must have at - tributes
started on it, and the attribute most have been en - abled using
enable.
EXAMPLES
- extattrctl start /
- Start extended attributes on the root file system.
extattrctl initattr 17 /.attribute/system/md5- Create an attribute backing file in /.attribute/system/md5,
- and set the
maximum size of each attribute to 17 bytes, with a sparse - file used for
storing the attributes.
extattrctl enable / system md5 /.attribute/system/md5- Enable an attribute named md5 on the root file system,
- backed from the
file /.attribute/system/md5.
extattrctl disable / md5- Disable the attribute named md5 on the root file system.
extattrctl stop /- Stop extended attributes on the root file system.
SEE ALSO
ffs(7), getextattr(8), setextattr(8), extattr(9)
HISTORY
- Extended attribute support was developed as part of the
- TrustedBSD Project, and introduced in FreeBSD 5.0. It was developed to
- support security extensions requiring additional labels to be associated
- with each
file or directory.
AUTHORS
- Robert N M Watson
- BSD March 30, 2000