MULTIPATH.CONF(5) File Formats Manual MULTIPATH.CONF(5) (NAME) multipath.conf - (multipathd) (DESCRIPTION) /etc/multipath.conf . multipathd . '#' () . . multipathd multipath -t multipathd show config . (drop-in) /etc/multipath/conf.d/ . .conf /etc/multipath.conf . /etc/multipath.conf . . (SYNTAX) :
{ ... { ... } } (section) (attribute) (subsection) . . . . ( '"' '#' '!') ("..."). '#' '!' . '#' '!' . ('""') . '2.5" SSD' "2.5"" SSD" . ('{') . ('}') . . (Regular Expressions): /etc/multipath.conf (POSIX Extended Regular Expressions regex(7) ) . (unanchored) "bar" "barbie" "rhabarber" "wunderbar" "Barbie" . "^" "$" . (section) : defaults device multipath . blacklist . blacklist_exceptions blacklist . multipaths . (WWID) . WWID WWID (WWID generation) . . devices . (vendor) (product) (revision) . overrides (override) . defaults (defaults section) defaults : verbosity . . 0 6 . : 2 polling_interval . max_polling_interval . systemd WatchdogSec multipathd.service . : 5 max_polling_interval . : 4 * polling_interval reassign_maps device-mapper. multipathd device-mapper . yes no. : no multipath_dir () . path_selector : round-robin 0 / . queue-length 0 ( 2.6.31 ) / / . service-time 0 ( 2.6.31 ) / ( ) / . historical-service-time 0 ( 5.8 ) / / . : service-time 0 path_grouping_policy ( ) . : failover . multibus . group_by_serial . group_by_prio . (callout) . group_by_node_name . /sys/class/fc_transport/target*/node_name . group_by_tpg ALUA. prio alua . : failover detect_pgpolicy yes alua sysfs group_by_prio . no path_grouping_policy . : yes detect_pgpolicy_use_tpg detect_pgpolicy yes alua sysfs group_by_tpg . no path_grouping_policy detect_pgpolicy . : no pg_timeout () . uid_attrs uevent WWID uevent . udev (WWID) . "type:ATTR" type ( sd:ATTR sda ) ATTR udev . WWID . reconfigure multipathd . : . uevent "sd:ID_SERIAL dasd:ID_UID nvme:ID_WWN" . uid_attribute udev (WWID) . uid_attribute WWID sysfs udev ( WWID (WWID generation) ). : ID_SERIAL SCSI : ID_UID DASD : ID_WWN NVMe getuid_callout () . prio . . . "none" . : const 1 . sysfs sysfs access_state preferred_path . prio_arg exclusive_pref_bit . emc ( ) DGC CLARiiON CX/AX EMC VNX Failover Mode 1 ( Passive Not Ready - PNR). alua ( ) ALUA SCSI-3. prio_arg exclusive_pref_bit . ontap ( ) NetApp ONTAP FAS/AFF (rebranded) ONTAP ( ALUA). rdac ( ) LSI/Engenio/NetApp RDAC NetApp SANtricity E/EF "Linux DM-MP (Kernel 3.9 or earlier)". hp_sw ( ) HP/COMPAQ/DEC HSG80 MSA/HSV Active/Standby. hds ( ) Hitachi AMS AMS 2000. random 1 10. weightedpath . prio_args . path_latency (latency). prio_args . ana ( ) ANA NVMe. datacore ( ) DataCore. prio_args . iet ( iSCSI) iSCSI IP. prio_args . detect_prio : detect_prio yes () sysfs ( NetAPP E/EF alua ). detect_prio no const . prio_args prio . : weighted : " ..." hbtl H:B:T:L . : 1:0:.:. *:0:0:. devname . : sda sd.e serial . : .*J1FR.*324 . sysfs multipathd show paths format "%z" . : 0395J1FR904324 wwn "host_wwnn:host_wwpn:target_wwnn:target_wwpn" sysfs multipathd show paths format "%N:%R:%n:%r" . : 0x200100e08ba0aea0:0x210100e08ba0aea0:.*:.* .*:.*:iqn.2009-10.com.redhat.msp.lab.ask-06:.* path_latency "io_num=<20> base_num=<10>" io_num / . : [20, 200]. base_num . : [1.1, 10]. 100s 1us . : base_num=10 <=1us (1us, 10us] (10us, 100us] (100us, 1ms] (1ms, 10ms] (10ms, 100ms] (100ms, 1s] (1s, 10s] (10s, 100s] >100s . alua exclusive_pref_bit preferred path . sysfs exclusive_pref_bit preferred path . datacore preferredsds () SDS ("SDS name"). timeout () INQUIRY . iet preferredip=... () IPv4 iSCSI. 20 () 0 () . CIDR (/ IPv4) . CIDR n.n.n.n/p 192.168/16 192.168.0.0/16. IP iSCSI . ( ) . IP 0 . : 10/8:20,10.0.10/24:40,192.168/16:10,0/0:5. : <> features device-mapper . num list num ( 0 8) list . : queue_if_no_path ( no_path_retry ) / . queue no_path_retry . no_path_retry . (KNOWN ISSUES) . pg_init_retries ( 2.6.24 ) pg_init 1 50 . pg_init_delay_msecs ( 2.6.38 ) pg_init 0 60000 . queue_mode ( 4.8 ) . bio rq mq bio (blk-mq) . 4.20 dm_mod.use_blk_mq mq rq . 4.20 rq mq (block-multiqueue) . queue_mode . nvme:tcp queue_mode bio . nvme:tcp . : 0 path_checker . 0.15.0 multipath-tools (asynchronous) multipathd . force_sync . : readsector0 () ( ) . tur directio . tur ( ) TEST UNIT READY SCSI. emc_clariion ( ) DGC/EMC EVPD page 0xC0 CLARiiON CX/AX EMC VNX Unity. hp_sw ( ) HP/COMPAQ/DEC HSG80 MSA/HSV Active/Standby. rdac ( ) LSI/Engenio/NetApp RDAC NetApp SANtricity E/EF . directio / (Direct I/O). . checker_timeout . cciss_tur ( ) HP/COMPAQ Smart Array(CCISS). none sysfs . : tur alias_prefix user_friendly_names. : mpath failback (failback) multipathd . immediate . immediate . manual failback . followover Active/Passive . failback . failback failover . values > 0 ( ). : manual rr_min_io ( 4.6) . rr_min_io_rq ( 4.6) . max_fds multipath multipathd . ulimit -n . max /proc/sys/fs/nr_open . 1024 . 32 1024 . : max rr_weight ( 4.6) . no_path_retry . : value > 0 /. fail ( /). queue / queue_if_no_path. (KNOWN ISSUES) . : fail queue_without_daemon no multipathd . no_path_retry . multipathd I/O . multipathd I/O . queue_without_daemon no . : no checker_timeout . scsi checker_timeout . checker_timeout (down) . : /sys/block//device/timeout allow_usb_devices no USB . USB yes . : no flush_on_last_del always multipathd . never multipathd . multipath never queue_if_no_path multipathd . unused multipathd kpartx . : unused user_friendly_names yes /etc/multipath/bindings prefix ( prefix alias_prefix mpath) . no WWID . multipaths . : no fast_io_fail_tmo SCSI FC / . dev_loss_tmo . off . : 5 dev_loss_tmo SCSI . "infinity" 136 (2^32-1 ) . Fibre Channel SAS . dev_loss_tmo . fast_io_fail_tmo multipathd dev_loss_tmo no_path_retry * polling_interval . fast_io_fail_tmo dev_loss_tmo 600 . no_path_retry dev_loss_tmo / polling_interval . no_path_retry "queue" . (KNOWN ISSUES) . . dev_loss_tmo . Fibre Channel SAS dev_loss_tmo . multipath-tools . multipath -T . : < > eh_deadline ( ) SCSI scsi . scsi HBA . fast_io_fail_tmo dev_loss_tmo scsi ( ) . : scsi HBA HBA . eh_deadline HBA . : <> max_retries SCSI / SCSI . / . SCSI 5 . multipath / . 0 5 . : <> bindings_file () . wwids_file () . prkeys_file () . log_checker_err once multipathd 2 . 3 . always multipathd 2 . : always reservation_key mpathpersist . RESERVATION KEY PERSISTENT RESERVE OUT 8 nexus I_T . mpathpersist --param-aptpl :aptpl . file RESERVATION KEY mpathpersist /etc/multipath/prkeys . multipathd . RESERVATION KEY /etc/multipath/prkeys . prkeys --param-aptpl . : <> all_tg_pt << >> (all targets ports) mpathpersist . . ALL_TG_PT mpathpersist . mpathpersist --param-alltgpt . : no retain_attached_hw_handler ( >= 4.3) yes SCSI hardware_handler multipath hardware_handler /etc/multipath.conf . SCSI multipath . : yes : 4.3 "retain_attached_hw_handler yes" . detect_prio yes multipath SCSI-3 ALUA . sysfs access_state preferred_path sysfs alua . no . : yes detect_checker yes multipath SCSI-3 ALUA . tur . no . : yes force_sync yes multipathd . multipathd . multipathd CPU . : no strict_timing yes multipathd polling_interval . . polling_interval . : no deferred_remove yes multipathd . . . : no partition_delimiter ( ) . "/UNSET/" ( ) multipath . ( "/UNSET/" ) : "p" . "/UNSET/" <> . multipath -T . : <> config_dir () . san_path_err_threshold 0 multipathd . san_path_err_threshold san_path_err_recovery_time . san_path_err_forget_rate . " (Shaky paths detection)" . : no san_path_err_forget_rate 0 multipathd ( san_path_err_forget_rate) san_path_err_threshold . san_path_err_recovery_time . " (Shaky paths detection)" . : no san_path_err_recovery_time 0 multipathd san_path_err_forget_rate san_path_err_threshold san_path_err_recovery_time . san_path_err_recovery_time . san_path_err_recovery_time . " (Shaky paths detection)" . : no marginal_path_double_failed_time I/O . marginal_path_double_failed_time I/O multipathd 10 I/O . " (Shaky paths detection)" . : no marginal_path_err_sample_time I/O . 120 marginal_path_double_failed_time I/O multipathd 10 I/O marginal_path_err_sample_time . I/O marginal_path_err_rate_threshold marginal_path_err_recheck_gap_time . marginal_path_err_recheck_gap_time . . " (Shaky paths detection)" . : no marginal_path_err_rate_threshold ( 1/1000). I/O . marginal_path_err_sample_time . I/O marginal_path_err_recheck_gap_time . " (Shaky paths detection)" . : no marginal_path_err_recheck_gap_time I/O . marginal_path_err_sample_time . I/O marginal_path_err_rate_threshold marginal_path_err_recheck_gap_time . marginal_path_err_recheck_gap_time . . " (Shaky paths detection)" . : no delay_watch_checks () san_path_err_forget_rate . 0 san_path_err san_path_err_forget_rate delay_watch_checks san_path_err_threshold 1 . san_path_err_forget_rate san_path_err_threshold " (Shaky paths detection)" . : no delay_wait_checks () san_path_err_recovery_time . 0 san_path_err san_path_err_recovery_time delay_wait_checks max_polling_interval . delay_wait_checks . san_path_err_threshold 1 . san_path_err_recovery_time san_path_err_threshold " (Shaky paths detection)" . : no marginal_pathgroups off delay_*_checks marginal_path_* san_path_err_* " (shaky)" . multipathd . I/O I/O . on . I/O . . fpin multipathd fpin "marginal" on . " " ( ) . : fpin marginal_path_* san_path_err_* no . multipathd fpin multipathd . " (Shaky paths detection)" . : off find_multipaths multipath multipathd . : ) udev multipath -u ( - LVM - ) ) multipathd . : strict multipath multipathd /etc/multipath/wwids . multipathd add map . WWIDs . off Multipath strict . Multipathd greedy . no 0 off . on multipathd multipath strict WWID . yes 1 on . greedy multipathd multipath . smart find_multipaths on . udev . multipathd WWID . . uevent udev . : . : strict find_multipaths_timeout find_multipaths "smart" ( ) . . ( ) "" multipath ( device) ("") 1 . 0 " " . find_multipaths smart . : -10 (10 1 ) uxsock_timeout CLI . CLI multipathd CLI . "timeout receiving packet" CLI . CLI . : 4000 retrigger_tries multipathd WWID uevent . : 3 retrigger_delay . : 10 missing_uev_wait_timeout multipathd udev . multipathd change uevent . : 30 skip_kpartx yes kpartx . : no purge_disconnected yes multipathd . TUR ( ) "LOGICAL UNIT NOT SUPPORTED" ( 0x5 ASC/ASCQ 0x25/0x00) . LUN . . : no disable_changed_wwids () . remove_retries multipath . multipath 1 . : 0 max_sectors_kb max_sectors_kb . max_sectors_kb / 1024 / . SCSI . . / . multipathd . . max_sectors_kb . . /etc/multipath.conf . . / max_sectors_kb . / ( ) . max_sectors_kb . . /etc/multipath.conf multipathd reconfigure multipathd del path multipathd add path . : <> ghost_delay multipath (ghost) systemd . multipath . 0 no multipath . : no auto_resize multipathd . never multipathd resize map . grow_only multipathd . grow_shrink multipathd . : never enable_foreign ( (FOREIGN MULTIPATH SUPPORT) ). ( "nvme") . . "nvme" NVMe ".*" . : "NONE" recheck_wwid yes wwid . wwid . Multipathd wwid . SCSI uid_attribute ID_SERIAL sysfs wwid . : no blacklist blacklist_exceptions (blacklist and blacklist_exceptions sections) blacklist . ( LUN ) multipath-tools . blacklist blacklist_exceptions "!" . "!^sd[a-z]" "sd[a-z]" . ("\!") ! . : . blacklist_exceptions blacklist . (" ") blacklist . "" blacklist_exceptions multipath-tools . . . devnode /. blacklist "!^(sd[a-z]|dasd[a- z]|nvme[0-9])" . scsi dasd nvme . wwid (WWID) /. device . vendor product . . devices . property udev. udev / . property udev "blacklisted, udev property missing" . : multipath-tools 0.8.2 . uid_attribute ( ID_SERIAL) . I/O . (blacklist exception) : (SCSI_IDENT_|ID_WWN) SCSI WWN ( ) . protocol /. multipath : scsi:fcp scsi:spi scsi:ssa scsi:sbp scsi:srp scsi:iscsi scsi:sas scsi:adt scsi:ata scsi:unspec nvme:pcie nvme:rdma nvme:fc nvme:tcp nvme:loop nvme:apple-nvme nvme:unspec ccw cciss undef. : multipathd show paths format "%d %P" "property, devnode, device, protocol, wwid" . multipathd . . : find_multipaths multipath-tools . multipaths (multipaths section) multipaths . multipaths ( ) overrides . multipaths multipath . multipath WWID . multipath : wwid () (World Wide Identifier). . wwid blacklist WWID multipaths . alias . WWID /etc/multipath/bindings . overrides devices defaults : path_grouping_policy path_selector prio prio_args failback no_path_retry flush_on_last_del features reservation_key user_friendly_names deferred_remove san_path_err_threshold san_path_err_forget_rate san_path_err_recovery_time marginal_path_err_sample_time marginal_path_err_rate_threshold marginal_path_err_recheck_gap_time marginal_path_double_failed_time delay_watch_checks delay_wait_checks skip_kpartx purge_disconnected max_sectors_kb ghost_delay devices (devices section) : multipath-tools . multipath-tools . . multipath-tools . devices . . . /etc/multipath/conf.d/ ( ) /etc/multipath.conf . . devices device . vendor product revision ( regex(7) ) . vendor product revision multipath multipathd . SCSI SCSI INQUIRY . 'multipathd show paths format "%d %s"' . device : vendor () . DASD : IBM NVMe : NVME product () . DASD : S/390 DASD ECKD revision . . product_blacklist vendor . device blacklist vendor vendor product product_blacklist . alias_prefix user_friendly_names "mpath". vpd_vendor vpd vpd. vpd sg_vpd -e . multipathd %g multipathd show maps format multipathd show paths format . vpd hp3par . hardware_handler . : 1 emc ( ) DGC CLARiiON CX/AX EMC VNX Failover Mode 1 (Passive Not Ready - PNR). 1 rdac ( ) LSI/Engenio/NetApp RDAC NetApp SANtricity E/EF "Linux DM-MP (Kernel 3.9 or earlier)". 1 hp_sw ( ) HP/COMPAQ/DEC HSG80 MSA/HSV Active/Standby. 1 alua ( ) SCSI-3 ALUA. 1 ana ( ) NVMe ANA. : <> : 4.3 ( SCSI-3 ALUA) . hardware_handler . defaults : path_grouping_policy uid_attribute path_selector path_checker prio prio_args features failback no_path_retry fast_io_fail_tmo dev_loss_tmo eh_deadline flush_on_last_del user_friendly_names retain_attached_hw_handler detect_prio detect_checker deferred_remove san_path_err_threshold san_path_err_forget_rate san_path_err_recovery_time marginal_path_err_sample_time marginal_path_err_rate_threshold marginal_path_err_recheck_gap_time marginal_path_double_failed_time delay_watch_checks delay_wait_checks skip_kpartx purge_disconnected max_sectors_kb ghost_delay all_tg_pt overrides (overrides section) overrides devices defaults : path_grouping_policy uid_attribute path_selector path_checker alias_prefix features prio prio_args failback no_path_retry flush_on_last_del fast_io_fail_tmo dev_loss_tmo eh_deadline user_friendly_names retain_attached_hw_handler detect_prio detect_checker deferred_remove san_path_err_threshold san_path_err_forget_rate san_path_err_recovery_time marginal_path_err_sample_time marginal_path_err_rate_threshold marginal_path_err_recheck_gap_time marginal_path_double_failed_time delay_watch_checks delay_wait_checks skip_kpartx purge_disconnected max_sectors_kb ghost_delay all_tg_pt overrides protocol protocol . type protocol . protocol overrides . protocol . protocol subsection protocol : type . scsi:fcp scsi:spi scsi:ssa scsi:sbp scsi:srp scsi:iscsi scsi:sas scsi:adt scsi:ata scsi:unspec nvme:pcie nvme:rdma nvme:fc nvme:tcp nvme:loop nvme:apple-nvme nvme:unspec ccw cciss undef. . : multipathd show paths format "%d %P" overrides devices defaults : fast_io_fail_tmo dev_loss_tmo eh_deadline WWID (WWID generation) Multipath (WWID) . WWID . WWID ( ): uid_attrs WWID udev uid_attrs . uid_attribute udev uid_attribute . sysfs WWID sysfs. SCSI (VPD) "Device Identification" (0x83) . ( udev uid_attribute ) . uevent uid_attrs . (Shaky paths detection) SAN : . . . multipathd . : " (shaky)" " (flipping)" () . " (delayed)" . marginal_pathgroups (marginal) . . . "" . "delay_checks" () "san_path_err" . delay_watch_checks delay_wait_checks . "marginal_path" ( ) marginal_path_double_failed_time : / . marginal_path_err_sample_time . . marginal_path_err_rate_threshold . marginal_path_err_recheck_gap_time . . "san_path_err" multipathd . san_path_err_threshold san_path_err_recovery_time . multipathd "san_path_err_forget_rate" " " . multipathd polling_interval max_polling_interval . "marginal_path" . "FPIN" (Fabric Performance Impact Notifications FPINs) . fpin ELS multipathd marginal . . . "marginal_path" "san_path_err" 0 . (FOREIGN MULTIPATH SUPPORT) multipath multipathd " (foreign)" (device mapper) . . : # multipath -ll uuid.fedcba98-3579-4567-8765-123456789abc [nvme]:nvme4n9 NVME,Some NVMe controller,FFFFFFFF size=167772160 features='n/a' hwhandler='ANA' wp=rw |-+- policy='n/a' prio=50 status=optimized | `- 4:38:1 nvme4c38n1 0:0 n/a optimized live `-+- policy='n/a' prio=50 status=optimized `- 4:39:1 nvme4c39n1 0:0 n/a optimized live "nvme" NVMe . multipath . (KNOWN ISSUES) queue_if_no_path LUN D state ( ) . no_path_retry . queue_if_no_path no_path_retry dev_loss_tmo I/O (deadlock) . dev_loss_tmo . : no_path_retry, queue_if_no_path, dev_loss_tmo. (FILES) : /etc/multipath.conf . /etc/multipath/conf.d/ (drop-in) . /etc/multipath/bindings (bindings) user_friendly_names yes . /etc/multipath/prkeys multipathd WWID reservation_key file . /etc/multipath/wwids (WWIDs) multipath WWID LUN . /run/multipathd.pid (PID). (SEE ALSO) udev(8), dmsetup(8), multipath(8), multipathc(8), multipathd(8). (AUTHORS) multipath-tools (Christophe Varoqui) . Linux 2026-06-13 MULTIPATH.CONF(5)