NAME    [Toc]    [Back]

     extattrctl - manage FFS extended attributes

SYNOPSIS    [Toc]    [Back]

     extattrctl start path
     extattrctl stop path
     extattrctl initattr [-f] [-p path] attrsize attrfile
     extattrctl enable path attrnamespace attrname attrfile
     extattrctl disable path attrnamespace attrname

DESCRIPTION    [Toc]    [Back]

     extattrctl is the management utility for extended attributes
over the FFS
     file system.  extattrctl 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 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 FFS  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 available
  for attributes when they are written, preventing low disk
             space conditions from denying attribute service.

             This file should not exist before running  initattr.

     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  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 must have  been  enabled
using enable.

EXAMPLES    [Toc]    [Back]

           # extattrctl start /

     Start extended attributes on the root file system.

           # extattrctl initattr 17 /.attribute/md5

     Create an attribute backing file in /.attribute/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/md5

     Enable  an  attribute  named  md5  on  the root file system,
backed from the
     file /.attribute/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    [Toc]    [Back]

     getextattr(8), setextattr(8), extattr(9)

HISTORY    [Toc]    [Back]

     Extended attribute support was  developed  as  part  of  the
TrustedBSD Project.
   It  was developed to support security extensions requiring additional
 labels to be associated with each file or  directory.

AUTHORS    [Toc]    [Back]

     Robert N M Watson

OpenBSD      3.6                          March      30,     2000