Multipath
Configurazione
File di configurazione del multipath con SuSE Sles9
##
## This is a template multipath-tools configuration file
## Uncomment the lines relevent to your environment
##
defaults {
default_features "1 queue_if_no_path"
# multipath_tool "/sbin/multipath -v0"
# udev_dir /dev
# polling_interval 10
# default_selector "round-robin 0"
# default_path_grouping_policy multibus
# default_getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
# default_prio_callout "/bin/true"
# default_features "0"
# rr_min_io 100
# rr_weight priorities
# failback immediate
}
devnode_blacklist {
wwid 41021712362D87000000
wwid 1AMCC_41021712362D87000000
devnode "^(ram|raw|loop|fd|md|dm-|system-|sr|scd|st)[0-9]*"
devnode "^hd[a-z][[0-9]*]"
devnode "^cciss!c[0-9]d[0-9]*[p[0-9]*]"
}
multipaths {
multipath {
wwid 3600508b4001063830000900000940000
alias vmware_transito
}
multipath {
wwid 3600508b40010638300009000009c0000
alias vmware_server
}
}
devices {
device {
vendor "HP "
product "HSV200 "
path_grouping_policy group_by_prio
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
path_checker tur
path_selector "round-robin 0"
prio_callout "/sbin/mpath_prio_alua %d"
failback immediate
}
}
# cat /etc/multipath.conf
blacklist {
wwid 20010b9fd080b7321
devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode "^hd[a-z][[0-9]*]"
devnode "^cciss!c[0-9]d[0-9]*[p[0-9]*]"
}
devices {
device {
vendor "EMC "
product "SYMMETRIX"
path_grouping_policy multibus
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
path_selector "round-robin 0"
features "0"
hardware_handler "0"
failback immediate
}
device {
vendor "DGC"
product "*"
path_grouping_policy group_by_prio
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
prio_callout "/sbin/mpath_prio_emc /dev/%n"
hardware_handler "1 emc"
features "1 queue_if_no_path"
no_path_retry 300
path_checker emc_clariion
failback immediate
}
}
multipaths {
multipath {
wwid
3600601608d1e170090af86321308db11
alias san1
path_grouping_policy failover
failback immediate
}
multipath {
wwid
360060160a1f4160072ee88ba1208db11
alias san2
path_grouping_policy failover
failback immediate
}
}
Con la SLES9 ci potrebbero essere seri problemi se si utilizzasse LVM2 su device multipath, poiché per default multipath non esegue la scansione della tavola delle partizioni e la creazione degli special files associati.
In pratica dopo l'esecuzione di boot.multipath i device /dev/mapper/mpathX sarebbero leggibili, ma gli eventuali devices relativi alle partizioni /dev/mapper/mpathXpY non lo sarebbero.
Per renderli leggibili bisogna eseguire il comando:
/sbin/kpartx -a /dev/mapper/mpathX
per ogni device.
Per fare ciò, può essere conveniente modificare boot.local in questo modo:
/sbin/modprobe dm-multipath /sbin/multipath /sbin/kpartx -a /dev/mapper/mpath0 /sbin/kpartx -a /dev/mapper/mpath1 /sbin/kpartx -a /dev/mapper/mpath2 /sbin/kpartx -a /dev/mapper/mpath3 vgscan --mknodes
http://support.novell.com/techcenter/sdb/en/2005/04/sles_multipathing.html
| Come configurare multipath per il root device
Config alternativo by RedHat & EMC2 CX300
devnode_blacklist {
devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode "^hd[a-z]"
devnode "^cciss!c[0-9]d[0-9]*"
}
defaults {
user_friendly_names yes
}
devices {
device {
vendor "DGC "
product "*"
path_grouping_policy group_by_prio
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
prio_callout "/sbin/mpath_prio_emc /dev/%n"
path_checker emc_clariion
path_selector "round-robin 0"
features "1 queue_if_no_path"
no_path_retry 300
hardware_handler "1 emc"
failback immediate
}
}
Referenze
https://help.ubuntu.com/lts/serverguide/multipath-admin-and-troubleshooting.html
Comandi
echo 'show config' | multipathd -k echo 'reconfigure' | multipathd -k echo 'list multipaths status' | multipathd -k echo 'list multipaths stats' | multipathd -k echo 'paths count' | multipathd -k