1 ZFD(7D)                             Devices                            ZFD(7D)
   2 
   3 NAME
   4      zfd - Zone file descriptor driver
   5 
   6 DESCRIPTION
   7      The zfd character driver exports devices into the zone which can be used
   8      by a a standalone process within the zone as stdin, stdout, and stderr.
   9      The zfd driver behaves in a similar manner as the zcons(7D) device.
  10      Inside a zone, the slave side devices appear as /dev/zfd/[0-4].
  11 
  12      The zone's zfd device configuration is driven by zoneadmd and a zone
  13      attribute zlog-mode which is somewhat of a misnomer since its purpose has
  14      evolved. The attribute can have a variety of values, but the lowest two
  15      positions in the value string are used to control how many zfd devices
  16      are created inside the zone and if the primary stream is a tty.
  17 
  18            --
  19            -n
  20            t-
  21            tn
  22 
  23      With the t flag set, stdin, stdout, and stderr, are multiplexed onto a
  24      single full-duplex stream which is configured as a tty.  That is, ptem,
  25      ldterm and ttycompat are autopushed onto the stream when the slave side
  26      is opened. There is only a single zfd device (0) needed for the primary
  27      stream.
  28 
  29      When the n flag is set, it is assumed that output logging will be done
  30      within the zone itself. In this configuration 1 or 2 additional zfd
  31      devices, depending on tty mode (t flag), are created within the zone. An
  32      application can then configure the zfd streams driver into a multiplexer.
  33      Output from the stdout/stderr zfd(s) will be teed into the correspond
  34      logging zfd(s) within the zone.
  35 
  36 
  37 SEE ALSO
  38      zlogin(1), zoneadmd(1M), zonecfg(1M), zcons(7D)
  39 
  40 illumos                        October 16, 2015                        illumos