vxiod(1m) [hpux man page]

vxiod(1M)																 vxiod(1M)

NAME

       vxiod - start, stop, and report on Veritas Volume Manager I/O threads

SYNOPSIS

       vxiod

       vxiod [-f ] [set count]

DESCRIPTION

       The  vxiod utility starts, stops, or reports on Veritas Volume Manager (VxVM) I/O kernel threads.  An I/O thread provides a process context
       for performing I/O in VxVM.

       When the vxio module is loaded, 16 I/O threads are created, plus 2 threads per additional CPU for a system with more than 8 CPUs, up  to  a
       maximum	of  64	threads.  At least one I/O thread must be running while the vxio module is loaded, and the number of I/O threads cannot be
       forced to zero.

       When invoked with no arguments, vxiod prints the current number of I/O threads to the standard output.

       The number of threads that is required for handling I/O requests depends on the system load and usage.  If volume recovery seems to proceed
       more slowly at times, it may be possible to improve its performance by increasing the number of I/O threads up to a maximum of 64.

KEYWORDS

       set	 When  invoked with the set keyword, vxiod creates the number of I/O threads specified by count.  If more volume I/O threads exist
		 than are specified by count, the excess processes terminate.  If more than the maximum number(64) are specified,  the  requested
		 number is silently truncated to that maximum.

OPTIONS

       -f	 This option has no effect from release 5.0 onward.  The number of I/O threads cannot be reduced to zero.

EXIT CODES

       The  vxiod  utility  prints a diagnostic on the standard error, and exits if an error is encountered. If an I/O request occurs within a I/O
       thread, the state of that I/O request is not reflected in the exit status for vxiod.  Otherwise, vxiod returns a non-zero  exit	status	on
       error.

       Usage  errors  result in an exit status of 1 and a usage message.  If the requested number of threads cannot be created, the exit status is
       2, and the number of threads that were successfully started is reported.  If any other error occurs, the exit status is 3.

FILES

       /dev/vx/iod		     The device used to report on and start volume I/O threads.

NOTES

       Veritas Volume Manager I/O threads cannot be killed directly through the use of signals.

       Depending on the operating system, VxVM I/O threads may not appear in the list of processes that is output by the ps command.   The  number
       of I/O threads that is currently running can be determined by running vxiod.

SEE ALSO

       fork(2), ps(1), vxconfigd(1M), vxdctl(1M), vxintro(1M), vxio(7), vxiod(7)

VxVM 5.0.31.1							    24 Mar 2008 							 vxiod(1M)

thr_join(3C)						   Standard C Library Functions 					      thr_join(3C)

NAME

       thr_join - wait for thread termination

SYNOPSIS

       cc -mt [ flag... ] file...[ library... ]
       #include <thread.h>

       int thr_join(thread_t thread, thread_t *departed, void **status);

DESCRIPTION

       The  thr_join()	function suspends processing of the calling thread until the target thread completes. The thread argument must be a member
       of the current process and cannot be a detached thread. See thr_create(3C).

       If two or more threads wait for the same thread to complete, all will suspend processing until the thread  has  terminated,  and  then  one
       thread will return successfully and the others will return with an error of ESRCH. The thr_join() function will not block processing of the
       calling thread if the target thread has already terminated.

       If a thr_join() call returns successfully with a non-null status argument, the value passed to thr_exit(3C) by the terminating thread  will
       be placed in the location referenced by status.

       If  the target thread ID is  0, thr_join() finds and returns the status of a terminated undetached thread in the process. If no such thread
       exists, it suspends processing of the calling thread until a thread for which no other thread is waiting enters that state, at  which  time
       it  returns  successfully,  or  until all other threads in the process are either daemon threads or threads waiting in thr_join(), in which
       case it returns EDEADLK. See NOTES.

       If departed is not NULL, it points to a location that is set to the ID of the terminated thread if thr_join() returns successfully.

RETURN VALUES

       If successful, thr_join() returns 0. Otherwise, an error number is returned to indicate the error.

ERRORS

       EDEADLK	   A joining deadlock would occur, such as when a thread attempts to wait for itself, or the calling thread  is  waiting  for  any
		   thread to exit and only daemon threads or waiting threads exist in the process.

       ESRCH	   No undetached thread could be found corresponding to the given thread ID.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       thr_create(3C), thr_exit(3C), wait(3C), attributes(5), standards(5)

NOTES

       Using thr_join(3C) in the following syntax,

	 while (thr_join(0, NULL, NULL) == 0);

       will wait for the termination of all non-daemon threads, excluding threads that are themselves waiting in thr_join().

SunOS 5.11							    27 Mar 2000 						      thr_join(3C)