[dm-devel] Multipath only round-robin
Markus
dieoma at gmail.com
Mon Sep 11 09:56:57 UTC 2006
Hello together,
I set up a testenviroment with 2xQLA2342 and have a active-active
capable Disk. I see the LUN 4 times which is fine and multipathed it
successfully to one. Failover works fine but writing is a bit "fuzzy"
since he only uses one path for 3sec or so and then the other path for
3 seconds - so a clearly "round-robin" bevaviour. As you can see in my
multipath.conf it should use multibus - so why is he doing this? I
think i saw an option in the multipath.conf but i don´t know which
value is "sensefull"...
Also i´am not sure why multipath says [undef] ?
Here some details:
linux-m8u1:/mnt # multipath -l
myisecondmultipath (36000d7700000030644cb1a8097fc3936) FALCON,IPSTOR DISK
[size=19G][features=1 queue_if_no_path][hwhandler=0]
\_ round-robin 0 [prio=0][active]
\_ 2:0:0:1 sdc 8:32 [active][undef]
\_ 2:0:1:1 sde 8:64 [active][undef]
\_ 3:0:0:1 sdg 8:96 [active][undef]
\_ 3:0:1:1 sdi 8:128 [active][undef]
myfirstmultipath (36000d77e00001e9a50d21a80a0506232) FALCON,IPSTOR DISK
[size=2G][features=1 queue_if_no_path][hwhandler=0]
\_ round-robin 0 [prio=0][active]
\_ 2:0:0:0 sdb 8:16 [active][undef]
\_ 2:0:1:0 sdd 8:48 [active][undef]
\_ 3:0:0:0 sdf 8:80 [active][undef]
\_ 3:0:1:0 sdh 8:112 [active][undef]
why does he say [undef] ???
Here the multipath.conf:
defaults {
multipath_tool "/sbin/multipath"
# udev_dir /dev
# polling_interval 10
# Pfadprüfinterval
polling_interval 5
# Queue IO for 36*5=180 Seconds=3min
(retries*polling_interval) then fail IO
# 3 min=default dynapath timeout
no_path_retry 36
# default_selector round-robin
# default_selector_args 0
default_path_grouping_policy multibus
# default_getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
#default_prio_callout "/etc/multipath_get_prio %n"
#default_prio_callout "/bin/false"
}
#
# name : multipaths
# scope : multipath & multipathd
# desc : list of multipaths finest-grained settings
multipaths {
multipath {
wwid 36000d77e00001e9a50d21a80a0506232
alias myfirstmultipath
}
multipath {
wwid 36000d7700000030644cb1a8097fc3936
alias myisecondmultipath
}
}
uname -a
Linux linux-m8u1 2.6.16.21-0.8-smp #1 SMP Mon Jul 3 18:25:39 UTC 2006
i686 i686 i386 GNU/Linux
Hopefully someone could shine some light on that...
Thanks in advance
Markus
More information about the dm-devel
mailing list