EXTATTRCTL(8)		  BSD System Manager's Manual		 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 extended attributes
     over the UFS1 file system.  It allows the starting and stopping of
     extended attributes on a file system, as well as initialization of
     attribute backing files, and enabling and disabling of specific extended
     attributes on a file system.

     The first argument on the command line indicates the operation to be per‐
     formed.  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 attribute will
	     be stored, using attrfile.

	     The -f argument may be used to indicate that it is alright to
	     overwrite an existing attribute backing file; otherwise, 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 avail‐
	     able for attributes when they are written, preventing 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 initial‐
	     ized attribute file attrfile.  Available namespaces are "user"
	     and "system".  The backing file must have been initialized using
	     initattr before its first use.  Attributes must have been started
	     on the file system prior to the enabling of any attributes.

     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 attributes
	     started on it, and the attribute most have been enabled 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				   BSD