xlv_labd, xlv_plexd, xlvd - logical volume daemons
xlv_plexd [ -m #_subprocs ] [ -b blocksize ] [ -w sleep-interval ]
[ -v verbosity ] [ -h ]
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
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.
All three daemons are automatically started and do not need to be
PPPPaaaaggggeeee 2222 [ Back ]