MAXBUF

   MAXBUF sets the maximum allowable size for any single buffered
   I/O packet. Buffered I/O packets are allocated from the
   permanently resident nonpaged dynamic pool. The terminal,
   mailbox, and printer device drivers are examples of device
   drivers that perform buffered I/O.

   The number of bytes specified in the I/O request plus the size of
   a driver-dependent and function-dependent header area determine
   the required buffered I/O packet size. The size of the header
   area is a minimum of 16 bytes; there is no absolute upper limit.
   However, this header area is usually a few hundred bytes in size.

   The default value on Alpha and Integrity servers continues to be
   8192.

   The maximum value of MAXBUF is 64000 bytes.

   MAXBUF is a DYNAMIC parameter.