EXTATTRCTL(8)           OpenBSD System Manager's Manual          EXTATTRCTL(8)

NAME
     extattrctl - manage FFS extended attributes

SYNOPSIS
     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
     extattrctl is the management utility for extended attributes over the FFS
     file system.  extattrctl allows the starting and stopping of extended at-
     tributes 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 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 at-
             tributes 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.

     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 start-
             ed on it, and the attribute must have been enabled using enable.

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

HISTORY
     Extended attribute support was developed as part of the TrustedBSD Pro-
     ject.  It was developed to support security extensions requiring addi-
     tional labels to be associated with each file or directory.

AUTHORS
     Robert N M Watson

OpenBSD 3.5                     March 30, 2000                               2
