[dm-devel] Multipath path ready but not active

[Jim Lester <Jim Lester compellent com>]

We were doing some testing today with SLES, multipathing and iSCSI. During the test we fail our port on the storage controller which causes the target to move to a new port. The iSCSI initiator on the SLES box comes back just fine, but multipath doesn't re-activate the path, causing IO to hold. 

mpatha (36000d3100003d5000000000000000013) dm-7 COMPELNT,Compellent Vol
[size=30G][features=1 queue_if_no_path][hwhandler=0]
\_ round-robin 0 [prio=1][enabled]
 \_ 5:0:0:5 sdm 8:192 [failed][ready]

If we run 'multipath' from the command line the path becomes active again and everything resumes. The failback parameter isn't set, so it should be doing the default behavior of immediate, but even when we set it, it didn't work correctly. 

Below is our multipath.conf file as well as all the version involved. Does anybody have any input?

defaults {
        user_friendly_names             yes
        path_grouping_policy            multibus
}

blacklist {
        devnode         "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
        devnode         "^hd[a-z][[0-9]*]"
        vendor          "*"
}

blacklist_exceptions {
        vendor  "COMPELNT"
}

devices {
        device {
                vendor                          COMPELNT
                product                         "Compellent Vol"
                path_checker                    tur
                polling_interval                10
                no_path_retry                   queue
        }
}


Linux manns 2.6.16.60-0.21-smp #1 SMP Tue May 6 12:41:02 UTC 2008 x86_64 x86_64 x86_64 GNU/Linux
multipath-tools v0.4.8 (08/02, 2007)
iscsid version 2.0-868

---
Jim Lester | Linux/Mac Product Specialist
Jim Lester Compellent com
(o) 952.294.2802
(c) 763.218.6012
Compellent Technologies | www.compellent.com