ggd(1M)								       ggd(1M)

NAME    [Toc]    [Back]

     ggd - rate-guarantee-granting daemon

SYNOPSIS    [Toc]    [Back]

     ggd [ -v dbglevel ] [ -c cpunum ] [ -o iosize ]

DESCRIPTION    [Toc]    [Back]

     ggd manages the I/O-rate guarantees that have been	granted	to processes
     on	the system.  The daemon	is started from	a script in the	/etc/rc2.d
     directory.	 It reads the /etc/grio_disks file to obtain information about
     the available hardware devices.  Processes	can make requests for I/O-rate
     guarantees	by using the grio_action_list(3X), grio_reserve_file(3X), or
     grio_reserve_fs(3X) library calls.	 After determining if the I/O rate can
     be	guaranteed, the	daemon returns a confirmation or rejection to the
     calling process.

     The /etc/grio_disks file is only read when	the daemon is started.	If
     this file is edited, the daemon must be stopped and restarted in order to
     use the new information.

     The -v option causes the ggd daemon to display verbose execution
     information.  The dbglevel	can be set from	0 to 10.  0 indicating no
     verbose output, and 10 indicating most verbose output.  The -o option
     allows the	specification of an optimal iosize other than the default
     value of 64K. The iosize is specified as 64, 128, 256 or 512.  The	-c
     option causes the daemon to mark the given	cpunum cpu as a	real-time cpu.
     The cpu is	isolated from the rest of the processors on the	system and the
     ggd daemon	is allowed to only run on this cpu.  See the sysmp(2)
     reference page for	more information on real-time processing.

FILES    [Toc]    [Back]

     /etc/grio_disks

SEE ALSO    [Toc]    [Back]

     sysmp(2), grio_associate_file(3X),	grio_query_fs(3X),
     grio_action_list(3X), grio_reserve_file(3X), grio_reserve_fs(3X),
     grio_unreserve_bw(3X), grio_disks(4).

NOTES    [Toc]    [Back]

     If	the ggd	daemon is killed and restarted,	all previous rate guarantees
     become invalid.  It creates a lock	file, /tmp/grio.lock, to prevent more
     than one copy of the daemon from running concurrently.  To	make grio more
     secure, ggd has to	be run with the	priviledge of CAP_DEVICE_MGMT or as
     root.


									PPPPaaaaggggeeee 1111