[dm-devel] path checker in regards to failback

[Dale.R.Fowle at seagate.com]

Hi all, I have a question related to failover/failback. I'm running
0.4.5-0.11. I'm wondering what the path checker does for the multipathd
daemon.

Here's my senario:
I have two paths to a LUN, configure it with 'multipath -v 2 -p failover'.
Run some I/O down the path of the /dev/mapper/<device>.
I fail one of the paths either by pulling the fibre or disabling the port
it's connected to.
When I run 'multipath -ll' I see the failed path 'failed faulty'.
I restore the path physically.
Run 'multipath -ll' again to see the status and it's 'failed ready'.

Now, my question is, is multipathd supposed to handle making that path
'active ready'?
I have 'failback immediate' set in the /etc/multipath.conf file. And it
does do the immediate failback,...but based on the 'active ready' status.
To get to that status, I have to actually issue a 'multipath' command to
reinstate the path to active.

Is there something that I'm missing or am I just going to have to make a
cron job run every few minutes to do path status updates?

Thanks much,
Dale


Dale Fowle
Seagate Technology
Colorado Springs, CO
719-388-5584