[dm-devel] [multipath-tools] multipath -ll and offline devices

[Stefan Bader]

Hi, 

I got a report about strange behaviour of "multipath -l" if one of the 
devices that are used for
multipathing is set offline. In that case the code in libmultipath 
(discovery.c) just ends processing
and the output is incomplete.

The problem is that setting a scsi device offline (through sysfs state 
attribute) will remove the
device node in /dev. And this will cause pathinfo to abort which gives no 
output at all.
This looks strange and in that situation the path could be assumed as 
failed. On the other hand
if the device node just had been removed "failed" wouldn't be a correct 
state.

One solution might be to use the state attribute of the scsi device 
(wasn't that once called online?
*sigh*) to check for an offline device and set the path state to failed in 
that case. Or should the map
get updated as soon as the device is set offline, to remove the path?

Stefan Bader

SW Linux on zSeries Development & Services
Stefan.Bader at de.ibm.com
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