section recognizes the following keywords:
.TP 17
.B polling_interval
-interval between two path checks in seconds For properly functioning paths,
-the interval between checks will gradually increase to (4 * polling_interval);
+interval between two path checks in seconds. For properly functioning paths,
+the interval between checks will gradually increase to
+.B max_polling_interval;
default is
.I 5
.TP
+.B max_polling_interval
+maximal interval between two path checks in seconds; default is
+.I 4 * polling_interval
+.TP
.B udev_dir
directory where udev creates its device nodes; default is
.I /dev
.TP
+.B multipath_dir
+directory where the dynamic shared objects are stored; default is system
+dependent, commonly
+.I /lib/multipath
+.TP
.B verbosity
default verbosity. Higher values increase the verbosity level. Valid
levels are between 0 and 6; default is
.I 2
.TP
+.B reassign_maps
+enable reassigning of device-mapper maps. With this option multipathd
+will remap existing device-mapper maps to always point to multipath
+device, not the underlying block devices. Possible values are
+\fIyes\fR and \fIno\fR. Default is
+.I yes
+.TP
.B path_selector
The default path selector algorithm to use; they are offered by the
kernel multipath target. There are three selector algorithms.
The default program and args to callout to obtain a unique path
identifier. Should be specified with an absolute path. Default value
is
-.I /lib/udev/scsi_id --whitelisted --device=/dev/%n
-.TP
-.B prio_callout
-The default program and args to callout to obtain a path priority
-value. The specified program will be executed and should return a
-numeric value specifying the relative priority of this path. Higher
-number have a higher priority. A '%n' in the command line will be expanded
-to the device name, a '%b' will be expanded to the device number in
-.I major:minor
-format.
+.I /lib/udev/scsi_id --whitelisted --replace-whitespace --device=/dev/%n
+.TP
+.B prio
+The name of the path priority routine. The specified routine
+should return a numeric value specifying the relative priority
+of this path. Higher number have a higher priority.
.I "none"
-is a valid value. Currently the following path priority programs are
-implemented:
+is a valid value. Currently the following path priority routines
+are implemented:
.RS
.TP 12
-.B mpath_prio_emc /dev/%n
-Generate the path priority for EMC arrays
+.B const
+Return a constant priority of \fI1\fR.
+.TP
+.B emc
+Generate the path priority for EMC arrays.
.TP
-.B mpath_prio_alua /dev/%n
+.B alua
Generate the path priority based on the SCSI-3 ALUA settings.
.TP
-.B mpath_prio_ontap /dev/%n
+.B ontap
Generate the path priority for NetApp arrays.
.TP
-.B mpath_prio_rdac /dev/%n
-Generate the path priority for LSI/Engenio RDAC controller.
+.B rdac
+Generate the path priority for LSI/Engenio/NetApp E-Series RDAC controller.
.TP
-.B mpath_prio_hp_sw /dev/%n
+.B hp_sw
Generate the path priority for Compaq/HP controller in
active/standby mode.
.TP
-.B mpath_prio_hds_modular %b
+.B hds
Generate the path priority for Hitachi HDS Modular storage arrays.
.TP
+.B random
+Generate a random priority between 1 and 10.
+.TP 12
+.B weightedpath
+Generate the path priority based on the regular expression and the
+priority provided as argument. requires prio_args keyword.
+.TP
Default value is \fBnone\fR.
.RE
.TP
+.B prio_args
+Arguments to pass to to the prio function. Currently only used with
+.I weighted, which needs a value of the form
+.I "<hbtl|devname> <regex1> <prio1> <regex2> <prio2> ..."
+.I hbtl
+regex can be of SCSI H:B:T:L format Ex: 1:0:.:. , *:0:0:.
+.I devname
+regex can be of device name format Ex: sda , sd.e
+.TP
.B features
-Specify any device-mapper features to be used. The most common of
-these features is
-.I "1 queue_if_no_path"
-Note that this can also be set via the
+Specify any device-mapper features to be used. Syntax is
+.I num list
+where
+.I num
+is the number of features in
+.I list.
+Possible values for the feature list are
+.RS
+.TP 12
+.B queue_if_no_path
+Queue IO if no path is active; identical to the
.I no_path_retry
keyword.
.TP
+.B no_partitions
+Disable automatic partitions generation via kpartx.
+.RE
+.TP
.B path_checker
-The default method used to determine the paths' state. Possible values
+The default method used to determine the paths state. Possible values
are
.RS
.TP 12
.B readsector0
-Read the first sector of the device
+(Deprecated) Read the first sector of the device. This checker is being
+deprecated, please use \fIdirectio\fR instead
.TP
.B tur
Issue a
Check the path state for HP storage arrays with Active/Standby firmware.
.TP
.B rdac
-Check the path state for LSI/Engenio RDAC storage controller.
+Check the path state for LSI/Engenio/NetApp E-Series RDAC storage controller.
.TP
.B directio
Read the first sector with direct I/O.
.TP
-Default value is \fIreadsector0\fR.
+Default value is \fIdirectio\fR.
.RE
.TP
.B failback
-Tell the daemon to manage path group failback, or not to. 0 or
-.I immediate
-means immediate failback, values >0 means deferred failback (in
-seconds).
-.I manual
-means no failback. Default value is
-.I manual
+Tell multipathd how to manage path group failback.
+.RS
+.TP 12
+.B immediate
+Immediately failback to the highest priority pathgroup that contains
+active paths.
+.TP
+.B manual
+Do not perform automatic failback.
+.TP
+.B values > 0
+deferred failback (time to defer in seconds)
+.TP
+Default value is \fImanual\fR.
+.RE
.TP
.B rr_min_io
The number of IO to route to a path before switching to the next in
-the same path group. Default is
+the same path group. This is only for BIO based multipath. Default is
.I 1000
.TP
+.B rr_min_io_q
+The number of IO requests to route to a path before switching to the
+next in the same path group. This is only for request based multipath.
+Default is
+.I 1
+.TP
.B rr_weight
If set to \fIpriorities\fR the multipath configurator will assign
path weights as "path prio * rr_min_io". Possible values are
Default is
.I no
.TP
+.B flush_on_last_del
+If set to
+.I yes
+, multipathd will disable queueing when the last path to a device has been
+deleted. Default is
+.I no
+.TP
.B max_fds
Specify the maximum number of file descriptors that can be opened by multipath
and multipathd. This is equivalent to ulimit -n. A value of \fImax\fR will set
.TP
.B dev_loss_tmo
Specify the number of seconds the scsi layer will wait after a problem has
-been detected on a FC remote port before removing it from the system.
+been detected on a FC remote port before removing it from the system. This
+can be set to "infinity" which sets it to the max value of 2147483647
+seconds, or 68 years.
.TP
.B queue_without_daemon
If set to
.I no
, avoids this problem. Default is
.I yes
+.TP
+.B bindings_file
+The full pathname of the binding file to be used when the user_friendly_names option is set. Defaults to
+.I /var/lib/multipath/bindings
+.TP
+.B log_checker_err
+If set to
+.I once
+, multipathd logs the first path checker error at logging level 2. Any later
+errors are logged at level 3 until the device is restored. If set to
+.I always
+, multipathd always logs the path checker error at logging level 2. Default is
+.I always
.
.SH "blacklist section"
The
The following attributes are optional; if not set the default values
are taken from the
.I defaults
+or
+.I devices
section:
.sp 1
.PD .1v
.TP
.B path_selector
.TP
+.B prio
+.TP
+.B prio_args
+.TP
.B failback
.TP
+.B rr_weight
+.TP
+.B flush_on_last_del
+.TP
.B no_path_retry
.TP
.B rr_min_io
+.TP
+.B rr_min_io_q
+.TP
+.B features
.RE
.PD
.LP
.B product_blacklist
(Optional) Product strings to blacklist for this vendor
.TP
+.B alias_prefix
+(Optional) The user_friendly_names prefix to use for this
+device type, instead of the default "mpath"
+.TP
.B hardware_handler
(Optional) The hardware handler to use for this device type.
The following hardware handler are implemented:
.TP 12
.B 1 emc
Hardware handler for EMC storage arrays.
+.TP
+.B 1 rdac
+Hardware handler for LSI/Engenio/NetApp E-Series RDAC storage controller.
+.TP
+.B 1 hp_sw
+Hardware handler for Compaq/HP storage arrays in active/standby
+mode.
+.TP
+.B 1 alua
+Hardware handler for SCSI-3 ALUA compatible arrays.
.RE
.LP
The following attributes are optional; if not set the default values
.TP
.B path_checker
.TP
-.B features
+.B prio
.TP
-.B prio_callout
+.B prio_args
+.TP
+.B features
.TP
.B failback
.TP
.TP
.B rr_min_io
.TP
+.B rr_min_io_rq
+.TP
.B fast_io_fail_tmo
.TP
.B dev_loss_tmo
+.TP
+.B flush_on_last_del
.RE
.PD
.LP
It is advisable to use the
.B no_path_retry
option instead.
+.P
+The use of
+.B queue_if_no_path
+or
+.B no_path_retry
+might lead to a deadlock if the
+.B dev_loss_tmo
+setting results in a device being removed while I/O is still queued.
+The multipath daemon will update the
+.B dev_loss_tmo
+setting accordingly to avoid this deadlock. Hence if both values are
+specified the order of precedence is
+.I no_path_retry, queue_if_no_path, dev_loss_tmo
+
.SH "SEE ALSO"
.BR udev (8),
.BR dmsetup (8)
projects / platform / upstream / multipath-tools.git / blobdiff