HASTCTL(8)		  BSD System Manager's Manual		    HASTCTL(8)

NAME
     hastctl — Highly Available Storage control utility

SYNOPSIS
     hastctl create [-d] [-c config] [-e extentsize] [-k keepdirty]
	     [-m mediasize] name ...
     hastctl role [-d] [-c config] ⟨init | primary | secondary⟩ all | name ...
     hastctl list [-d] [-c config] [all | name ...]
     hastctl status [-d] [-c config] [all | name ...]
     hastctl dump [-d] [-c config] [all | name ...]

DESCRIPTION
     The hastctl utility is used to control the behaviour of the hastd(8) dae‐
     mon.

     This utility should be used by HA software like heartbeat or ucarp to
     setup HAST resources role when changing from primary mode to secondary or
     vice versa.  Be aware that if a file system like UFS exists on HAST
     provider and primary node dies, file system has to be checked for incon‐
     sistencies with the fsck(8) utility after switching secondary node to
     primary role.

     The first argument to hastctl indicates an action to be performed:

     create  Initialize local provider configured for the given resource.
	     Additional options include:

	     -e extentsize  Size of an extent.	Extent is a block which is
			    used for synchronization.  hastd(8) maintains a
			    map of dirty extents and extent is the smallest
			    region that can be marked as dirty.  If any part
			    of an extent is modified, entire extent will be
			    synchronized when nodes connect.  If extent size
			    is too small, there will be too much disk activity
			    related to dirty map updates, which will degrade
			    performance of the given resource.	If extent size
			    is too large, synchronization, even in case of
			    short outage, can take a long time increasing the
			    risk of losing up-to-date node before synchroniza‐
			    tion process is completed.	The default extent
			    size is 2MB.

	     -k keepdirty   Maximum number of dirty extents to keep dirty all
			    the time.  Most recently used extents are kept
			    dirty to reduce number of metadata updates.  The
			    default number of most recently used extents which
			    will be kept dirty is 64.

	     -m mediasize   Size of the smaller provider used as backend stor‐
			    age on both nodes.	This option can be omitted if
			    node providers have the same size on both sides.

	     If size is suffixed with a k, M, G or T, it is taken as a kilo‐
	     byte, megabyte, gigabyte or terabyte measurement respectively.

     role    Change role of the given resource.  The role can be one of:

	     init	Resource is turned off.

	     primary	Local hastd(8) daemon will act as primary node for the
			given resource.  System on which resource role is set
			to primary can use /dev/hast/<name> GEOM provider.

	     secondary	Local hastd(8) daemon will act as secondary node for
			the given resource - it will wait for connection from
			the primary node and will handle I/O requests received
			from it.  GEOM provider /dev/hast/<name> will not be
			created on secondary node.

     list    Present verbose status of the configured resources.

     status  Present terse (and more easy machine-parseable) status of the
	     configured resources.

     dump    Dump metadata stored on local component for the configured
	     resources.

     In addition, every subcommand can be followed by the following options:

     -c config	Specify alternative location of the configuration file.  The
		default location is /etc/hast.conf.

     -d 	Print debugging information.  This option can be specified
		multiple times to raise the verbosity level.

FILES
     /etc/hast.conf    Configuration file for hastctl and hastd(8).
     /var/run/hastctl  Control socket used by hastctl to communicate with the
		       hastd(8) daemon.

EXIT STATUS
     Exit status is 0 on success, or one of the values described in
     sysexits(3) on failure.

EXAMPLES
     Initialize HAST provider, create file system on it and mount it.

	   nodeB# hastctl create shared
	   nodeB# hastd
	   nodeB# hastctl role secondary shared

	   nodeA# hastctl create shared
	   nodeA# hastd
	   nodeA# hastctl role primary shared
	   nodeA# newfs -U /dev/hast/shared
	   nodeA# mount -o noatime /dev/hast/shared /shared
	   nodeA# application_start

     Switch roles for the shared HAST resource.

	   nodeA# application_stop
	   nodeA# umount -f /shared
	   nodeA# hastctl role secondary shared

	   nodeB# hastctl role primary shared
	   nodeB# fsck -t ufs /dev/hast/shared
	   nodeB# mount -o noatime /dev/hast/shared /shared
	   nodeB# application_start

SEE ALSO
     sysexits(3), geom(4), hast.conf(5), fsck(8), ggatec(8), ggatel(8),
     hastd(8), mount(8), newfs(8)

AUTHORS
     The hastctl was developed by Pawel Jakub Dawidek ⟨pjd@FreeBSD.org⟩ under
     sponsorship of the FreeBSD Foundation.

BSD				March 14, 2013				   BSD