ssum(1)

NAME
     ssum - Set file checksum attributes

SYNOPSIS
     ssum [-d] [-e] [-f] [-g] [-u] filename...

     ssum [-d] [-e] [-f] [-g] [-u] -r dirname...[filename...]

AVAILABILITY
     SUNWsamfs

DESCRIPTION
     ssum sets the checksum attributes on one or more files.   If
     the  generate attribute is set (-g), a 128-bit value is gen-
     erated when the file is archived.  When the file  is  subse-
     quently  staged, the checksum is again generated and is com-
     pared against the value generated at archive time if the use
     attribute  is  set  (-u).   By default, no checksum value is
     generated or used when archiving or staging a file.

     The generate attribute must be set  on  a  file  before  any
     archive  copy  has  been made.  Likewise, the selected algo-
     rithm cannot be changed after an archive copy has been made.

     Direct access (stage -n) and partial  release  (release  -p)
     are  not  allowed on a file that has the checksum use attri-
     bute set. Also, it is not valid to specify that a file never
     be  archived (archive -n) as well as specify that a checksum
     be used.  Therefore, when a direct access, partial  release,
     or  archive  never attribute is set on a file, attempting to
     set the checksum generate or use attribute on the file  will
     result  in  an  error  and the attributes will be unchanged.
     Similarly, when either the checksum generate or  use  attri-
     bute  is  set  on a file, attempting to set a direct access,
     partial release, or archive never attribute on the file will
     result in an error and the attributes will be unchanged.

     A file that has the checksum use  attribute  set  cannot  be
     memory  mapped.   The file also must be completely staged to
     the disk before access is allowed to the file's data.   This
     means  that  accessing  the first byte of offline data in an
     archived file that has this attribute  set  will  be  slower
     than  accessing the same archived file when it does not have
     this attribute set.   This  also  means  that  staging  will
     operate the same way as for staging with the -w option for a
     file with the use attribute not set.

OPTIONS
     -d   Return the file's checksum attributes to  the  default,
          which turns off checksumming.  Using the -d option will
          not reset the 'checksum valid' flag if a valid checksum
          has  been  generated  for a file. The -d option deletes

          the checksum attributes, if no valid checksum has  been
          generated.

     -e   Set data verification for the file or directory  speci-
          fied.   This forces the generation and use of checksums
          for archiving and staging, and prevents the release  of
          the file until all archive copies have been created and
          their checksums verified. A file with only one  archive
          copy  will  never be released. Only a superuser can set
          this attribute on a file.

          Files created in  directories  with  the  -e  flag  set
          inherit it.

     -f   Do not report errors.

     -r   Recursively set the attributes for any files  contained
          in the specified dirname and its subdirectories.

     -g   Generate a checksum value for the file when archiving.

     -u   Use the checksum value for the file when staging.   The
          generate  attribute  must  have been previously set, or
          must be set simultaneously.

SEE ALSO
     stage(1), release(1), archive(1), sls(1)