xlv_labd(7M)							  xlv_labd(7M)

NAME    [Toc]    [Back]

     xlv_labd, xlv_plexd, xlvd - logical volume	daemons

SYNOPSIS    [Toc]    [Back]

     xlv_labd
     xlv_plexd [ -m #_subprocs ] [ -b blocksize	] [ -w sleep-interval ]
	  [ -v verbosity ] [ -h	]

DESCRIPTION    [Toc]    [Back]

     xlv_labd, xlv_plexd, and xlvd are logical volume daemons.	xlv_labd and
     xlv_plexd reside in user process space and	xlvd resides in	kernel process
     space.

     The XLV label daemon, xlv_labd, is	a user process that writes logical
     volume disk labels.  It is	normally started during	system restart.	 Upon
     startup, xlv_labd immediately calls into the kernel to wait for an	action
     request from the kernel daemon, xlvd.  When an action request comes,
     xlv_labd processes	it and updates the appropriate volume disk labels.
     After completing the update, xlv_labd calls back into the kernel to wait
     for another request.

     The XLV plex copy daemon, xlv_plexd, is a user process responsible	for
     making all	plexes within a	subvolume consistent.  The master xlv_plexd
     process is	started	at system startup time with the	-m option and
     subsequently used when new	plexes are added.  It receives requests	to
     revive plexes via the named pipe /etc/.xlv_plexd_request_fifo and starts
     child processes to	perform	the actual plex	copy.

     -m	#_subprocs	 #_subprocs is the maximum number of subprocesses the
			 master	xlv_plexd process forks	off at any given time.

     -b	blocksize	 blocksize is the granularity of a single plex copy
			 operation in blocks.  The default is 128 blocks,
			 which means XLV initiates a plex copy of 128 blocks,
			 sleeps	as indicated by	the -w option (see below),
			 then moves on to the next set of 128 blocks.

     -w	sleep-interval	 sleep-interval	is an arbitrary	delay enforced at
			 regular intervals while performing a plex copy	in
			 order to share	available disk bandwidth.  The default
			 delay is 0.

     -v	verbosity	 verbosity is the level	of verbosity.  The minimum is
			 0 and the maximum is 3.  xlv_plexd writes its
			 messages to syslog.  The default verbosity is 2.

     -h			 Print the help	message.

     The XLV daemon, xlvd, is a	kernel process that handles I/O	to plexes and
     performs plex error recovery.  When disk labels require updating, xlvd
     initiates an action request to xlv_labd to	perform	the disk label update.
     If	there aren't multiple plexes, xlvd does	not do anything.



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xlv_labd(7M)							  xlv_labd(7M)

NOTE    [Toc]    [Back]

     All three daemons are automatically started and do	not need to be
     explicitly	invoked.

FILES    [Toc]    [Back]

     /etc/.xlv_plexd_request_fifo

SEE ALSO    [Toc]    [Back]

     xlv(7M).


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