@@ -1,4 +1,4 @@
-.TH MULTIPATH.CONF 5 2016-07-03 "Linux"
+.TH MULTIPATH.CONF 5 2016-07-06 "Linux"
.SH NAME
multipath.conf \- multipath daemon configuration file
.SH DESCRIPTION
@@ -25,8 +25,10 @@ The configuration file contains entries of the form:
<attribute> <value>
.I "..."
.RE
+.ft B
}
.RE
+.ft B
}
.ft R
.fi
@@ -56,7 +58,7 @@ section.
.B multipaths
This section defines the multipath topologies. They are indexed by a
\fIWorld Wide Identifier\fR(wwid). For details on the wwid generation
-see section \fBWWID generation\fR below.
+see section \fIWWID generation\fR below.
.TP
.B devices
This section defines the device-specific settings.
@@ -68,15 +70,15 @@ device-specific settings for all devices.
.LP
.SH "defaults section"
The
-.B defaults
+.I defaults
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
-.B max_polling_interval.
+.I max_polling_interval.
This value will be overridden by the
-.B WatchdogSec
+.I WatchdogSec
setting in the multipathd.service definition if systemd is used.
.RS
.TP
@@ -145,14 +147,14 @@ The default path selector algorithm to use; they are offered by the
kernel multipath target. There are three selector algorithms.
.RS
.TP 12
-.B "round-robin 0"
+.I "round-robin 0"
Loop through every path in the path group, sending the same amount of IO to
each.
.TP
-.B "queue-length 0"
+.I "queue-length 0"
Send the next bunch of IO down the path with the least amount of outstanding IO.
.TP
-.B "service-time 0"
+.I "service-time 0"
Choose the path for the next bunch of IO based on the amount of outstanding IO
to the path and its relative throughput.
.RE
@@ -162,21 +164,21 @@ The default path grouping policy to apply to unspecified
multipaths. Possible values are
.RS
.TP 12
-.B failover
+.I failover
1 path per priority group
.TP
-.B multibus
+.I multibus
all paths in 1 priority group
.TP
-.B group_by_serial
+.I group_by_serial
1 priority group per serial number
.TP
-.B group_by_prio
+.I group_by_prio
1 priority group per priority value. Priorities are determined by
callout programs specified as a global, per-controller or
per-multipath option in the configuration file.
.TP
-.B group_by_node_name
+.I group_by_node_name
1 priority group per target node name. Target node names are fetched
in /sys/class/fc_transport/target*/node_name.
.TP
@@ -204,34 +206,34 @@ is a valid value. Currently the following path priority routines
are implemented:
.RS
.TP 12
-.B const
+.I const
Return a constant priority of \fI1\fR.
.TP
-.B emc
+.I emc
Generate the path priority for EMC arrays.
.TP
-.B alua
+.I alua
Generate the path priority based on the SCSI-3 ALUA settings. This prioritizer
accepts the optional prio_arg
.I exclusive_pref_bit
.TP
-.B ontap
+.I ontap
Generate the path priority for NetApp arrays.
.TP
-.B rdac
+.I rdac
Generate the path priority for LSI/Engenio/NetApp E-Series RDAC controller.
.TP
-.B hp_sw
+.I hp_sw
Generate the path priority for Compaq/HP controller in
active/standby mode.
.TP
-.B hds
+.I hds
Generate the path priority for Hitachi HDS Modular storage arrays.
.TP
-.B random
+.I random
Generate a random priority between 1 and 10.
.TP 12
-.B weightedpath
+.I weightedpath
Generate the path priority based on the regular expression and the
priority provided as argument. requires prio_args keyword.
.TP
@@ -243,7 +245,7 @@ Arguments to pass to to the prio function. This only applies to certain
prioritizers
.RS
.TP 12
-.B weighted
+.I weighted
Needs a value of the form
.I "<hbtl|devname|wwn> <regex1> <prio1> <regex2> <prio2> ..."
.I hbtl
@@ -256,7 +258,7 @@ regex can be of the form
these values can be looked up through sysfs or by running
.I mulitpathd show paths format "%N:%R:%n:%r" Ex: 0x200100e08ba0aea0:0x210100e08ba0aea0:.*:.* , .*:.*:iqn.2009-10.com.redhat.msp.lab.ask-06:.*
.TP
-.B alua
+.I alua
If
.I exclusive_pref_bit
is set, paths with the TPGS pref bit set will always be in their own path
@@ -273,12 +275,12 @@ is the number of features in
Possible values for the feature list are
.RS
.TP 12
-.B queue_if_no_path
+.I queue_if_no_path
Queue IO if no path is active; identical to the
.I no_path_retry
keyword.
.TP
-.B no_partitions
+.I no_partitions
Disable automatic partitions generation via kpartx.
.RE
.TP
@@ -287,26 +289,26 @@ The default method used to determine the paths state. Possible values
are
.RS
.TP 12
-.B readsector0
+.I readsector0
(Deprecated) Read the first sector of the device. This checker is being
deprecated, please use \fItur\fR instead
.TP
-.B tur
+.I tur
Issue a
.I TEST UNIT READY
command to the device.
.TP
-.B emc_clariion
+.I emc_clariion
Query the EMC Clariion specific EVPD page 0xC0 to determine the path
state.
.TP
-.B hp_sw
+.I hp_sw
Check the path state for HP storage arrays with Active/Standby firmware.
.TP
-.B rdac
+.I rdac
Check the path state for LSI/Engenio/NetApp E-Series RDAC storage controller.
.TP
-.B directio
+.I directio
(Deprecated) Read the first sector with direct I/O. This checker is being
deprecated, it will cause spurious path failures under high load.
Please use \fItur\fR instead.
@@ -318,19 +320,19 @@ Default value is: \fBtur\fR
Tell multipathd how to manage path group failback.
.RS
.TP 12
-.B immediate
+.I immediate
Immediately failback to the highest priority pathgroup that contains
active paths.
.TP
-.B manual
+.I manual
Do not perform automatic failback.
.TP
-.B followover
+.I followover
Only perform automatic failback when the first path of a pathgroup
becomes active. This keeps a node from automatically failing back when
another node requested the failover.
.TP
-.B values > 0
+.I values > 0
deferred failback (time to defer in seconds)
.TP
Default value is: \fBmanual\fR
@@ -431,7 +433,7 @@ retry interval
\fIno_path_retry\fR * \fIpolling_interval\fR
if a number of retries is given with \fIno_path_retry\fR and the
overall retry interval is longer than the specified \fIdev_loss_tmo\fR value.
-The linux kernel will cap this value to \fI300\fR if \fBfast_io_fail_tmo\fR
+The linux kernel will cap this value to \fI300\fR if \fIfast_io_fail_tmo\fR
is not set.
.RS
.TP
@@ -633,9 +635,9 @@ Regular expression of the udev property to be excluded.
.TP
.B device
Subsection for the device description. This subsection recognizes the
-.I vendor
+.B vendor
and
-.I product
+.B product
keywords. For a full description of these keywords please see the
.I devices
section description.
@@ -667,9 +669,9 @@ Regular expression of the device nodes to be whitelisted.
.TP
.B device
Subsection for the device description. This subsection recognizes the
-.I vendor
+.B vendor
and
-.I product
+.B product
keywords. For a full description of these keywords please see the
.I devices
section description.
@@ -678,20 +680,20 @@ The
.I property
blacklist and whitelist handling is different from the usual handling
in the sense that the whitelist
-.B has
+.I has
to be set, otherwise the device will be blacklisted.
In these cases the message
.I blacklisted, udev property missing
will be displayed.
.SH "multipaths section"
The only recognized attribute for the
-.B multipaths
+.I multipaths
section is the
.I multipath
subsection.
.LP
The
-.B multipath
+.I multipath
subsection recognizes the following attributes:
.TP 17
.B wwid
@@ -744,7 +746,7 @@ section:
.LP
.SH "devices section"
The only recognized attribute for the
-.B devices
+.I devices
section is the
.I device
subsection.
@@ -774,17 +776,17 @@ device type, instead of the default "mpath"
The following hardware handler are implemented:
.RS
.TP 12
-.B 1 emc
+.I 1 emc
Hardware handler for EMC storage arrays.
.TP
-.B 1 rdac
+.I 1 rdac
Hardware handler for LSI/Engenio/NetApp E-Series RDAC storage controller.
.TP
-.B 1 hp_sw
+.I 1 hp_sw
Hardware handler for Compaq/HP storage arrays in active/standby
mode.
.TP
-.B 1 alua
+.I 1 alua
Hardware handler for SCSI-3 ALUA compatible arrays.
.RE
.LP
@@ -923,23 +925,23 @@ are present multipath will try to use the sysfs attribute
\fIvpd_pg83\fR to generate the wwid.
.SH "KNOWN ISSUES"
The usage of
-.B queue_if_no_path
+.I queue_if_no_path
option can lead to
-.B D state
+.I D state
processes being hung and not killable in situations where all the paths to the LUN go offline.
It is advisable to use the
-.B no_path_retry
+.I no_path_retry
option instead.
.P
The use of
-.B queue_if_no_path
+.I queue_if_no_path
or
-.B no_path_retry
+.I no_path_retry
might lead to a deadlock if the
-.B dev_loss_tmo
+.I 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
+.I 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
@@ -950,5 +952,5 @@ specified the order of precedence is
.BR multipath (8)
.BR multipathd (8)
.SH AUTHORS
-.B multipath
+.I multipath
was developed by Christophe Varoqui, <christophe.varoqui@opensvc.com> and others.
Do it more readable. Cc: Christophe Varoqui <christophe.varoqui@opensvc.com> Cc: device-mapper development <dm-devel@redhat.com> Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com> --- multipath/multipath.conf.5 | 116 +++++++++++++++++++++++---------------------- 1 file changed, 59 insertions(+), 57 deletions(-)