OK, I did notice that my Multipath Tools are a little old
[root@wpe02 sbin]# rpm -qa |grep -i multipath
device-mapper-multipath-0.4.7-12.el5_1.3
Running Oracle Linux 5. Which in truth is:
[root@wpe02 sbin]# cat /etc/redhat-release
Enterprise Linux Enterprise Linux Server release 5.1 (Carthage)
Guess I could grab the latest multipath tools from RedHat for ES 5.1.
Looks like I am on track now.
I looked in
/usr/share/doc/device-mapper-multipath-0.4.7/multipath.conf.defaults
And see the below. I guess that is what multipath is trying to use.
# device {
# vendor "HITACHI"
# product "DF.*"
# getuid_callout "/sbin/scsi_id -g -u -s
/block/%n"
# prio_callout "/sbin/mpath_prio_hds_modular
%d"
# features "0"
# hardware_handler "0"
# path_grouping_policy group_by_prio
# failback immediate
# rr_weight uniform
# rr_min_io 1000
# path_checker readsector0
# }
Created my own version of defaults in /etc/multipath.conf from that:
defaults {
udev_dir /dev
polling_interval 10
selector "round-robin 0"
path_grouping_policy group_by_prio
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
prio_callout "/sbin/mpath_prio_hds_modular /dev/%n"
path_checker readsector0
rr_min_io 1000
rr_weight uniform
failback immediate
no_path_retry fail
user_friendly_name yes
}
Then for an alias I use this:
multipath {
wwid 1HITACHI_D60090910032
alias asm01
}
Output from multipath -ll
asm01 (1HITACHI_D60090910032) dm-6 HITACHI,DF600F
[size=32G][features=0][hwhandler=0]
\_ round-robin 0 [prio=1][active]
\_ 0:0:1:32 sdm 8:192 [active][ready]
\_ round-robin 0 [prio=0][enabled]
\_ 0:0:0:32 sdb 8:16 [active][ready]
>From a multipathd -k, "show config"
device {
vendor HITACHI
product DF.*
prio_callout mpath_prio_hds_modular %d
}
So looks like maybe it is incorrect there?
Usually if that is messing up, it shows in /var/log/messages.
THANKS THANKS THANKS Tore!!!!!!!! Would be lost without the help!
Craig
-----Original Message-----
From: dm-devel-bounces@xxxxxxxxxx [mailto:dm-devel-bounces@xxxxxxxxxx]
On Behalf Of Tore Anderson
Sent: Wednesday, May 21, 2008 2:01 PM
To: device-mapper development
Cc: Michael Denney
Subject: Re: Round Robin vs Active/Passive
Hi,
* Craig Simpson
> Amazing Info, thanks!
Glad I could help.
> Changed my Defaults to this:
>
> defaults {
> udev_dir /dev
> polling_interval 10
> selector "round-robin 0"
> path_grouping_policy group_by_prio
> getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
> prio_callout /sbin/mpath_prio_hds_modular
> path_checker readsector0
> rr_min_io 100
> rr_weight priorities
> failback immediate
> no_path_retry fail
> user_friendly_name yes
> }
You need
prio_callout "/sbin/mpath_prio_hds_modular /dev/%n"
for the priority to be determined correctly.
Anyway I'm a bit surprised that you need to specify these things, the
AMS series do have a entry in hwtable.c in multipath-tools 0.4.8 at
least. Running an old version maybe? They don't differ much from what
you have there, though.
> So figure I don't need to include anything in my aliases, since the
> defaults are set.
You figure correctly.
> Did a multipathd -k
> And a reconfigure
You also need to actually reload the multipath maps in the kernel, by
invoking e.g. "multipath -v2".
> But when doing a multipath -l Not sure if it looks correct:
>
> asm01 (1HITACHI_D60090910032) dm-6 HITACHI,DF600F
> [size=32G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=0][enabled]
> \_ 0:0:1:32 sdm 8:192 [active][undef]
> \_ round-robin 0 [prio=0][enabled]
> \_ 0:0:0:32 sdb 8:16 [active][undef]
You need to use "multipath -ll" (two l's) for it to show you the
priority, but it looks like multipathd have everything figured out:
> Also a multipathd> show topology
>
> reload: asm01 (1HITACHI_D60090910032) dm-6 HITACHI,DF600F
> [size=32G ][features=0 ][hwhandler=0 ]
> \_ round-robin 0 [prio=1][enabled]
> \_ 0:0:1:32 sdm 8:192 [active][ready]
> \_ round-robin 0 [prio=0][enabled]
> \_ 0:0:0:32 sdb 8:16 [active][ready]
It's a bit strange that it actually is able to determine the priority,
considering that you have the prio_callout set incorrectly in your
defaults section.
I suspect that the default values from hwtable.c comes into play and
overrides your settings anyway. You can check this by running "show
config" from inside "multipathd -k" - if you have a device section for
your vendor HITACHI, product DF.* there that might be what's going on.
> Looks like I have [enabled] [enabled] ...
> But it should be [active] [enabled]
Have you sent any I/O to the device after the configuration change? The
PG doesn't transition from enabled to active before some regular I/O has
been sent there. Just reading some data from it should suffice.
Regards,
--
Tore Anderson
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