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