Hi,
we have some trouble with runnign an EMC CX400 with multipath and evms.
If we run the machine with systemtype 0x16 (it identifies itself as FSC FC66
then), Arraycommpath = 0 and Failovermode = 2, failover seems to work well
(not much tested), and evms uses the dm/multipath devices. The bad thing on
this way is a trespass of the LUNs every few seconds, which is not the way it
should work.
Setting the machine to something useful - systemtype=3 (==DGC),
arraycommpath=1, failovermode=1 - it is recognized by multipath-tools and
dm-emc as emc-machine. With
zeus-1:/# cat /etc/multipath.conf
defaults {
path_grouping_policy failover
no_path_retry queue
}
multipaths {
multipath {
wwid 3600601f2a20c0000fa13caa656b0d711
alias LUN_0
}
[....]
multipath {
wwid 3600601f4a20c000099dc229956b0d711
alias LUN_7
}
}
we have some nice devices:
zeus-1:/# ll /dev/mapper/
total 0
brw------- 1 root root 254, 0 Oct 29 12:09 LUN_0
brw------- 1 root root 254, 4 Oct 29 12:09 LUN_0p1
[....]
brw------- 1 root root 254, 2 Oct 29 12:09 LUN_7
brw------- 1 root root 254, 13 Oct 29 12:09 LUN_7p1
crw-rw---- 1 root root 10, 63 Oct 29 12:08 control
zeus-1:/#
but evms does not use them, it directly accesses and uses sd*
zeus-1:/# ll /dev/evms
[...]
drwxr-xr-x 2 root root 60 Oct 29 12:09 dm
brw-r----- 1 root disk 8, 0 Oct 29 12:09 sda
brw-r----- 1 root disk 8, 16 Oct 29 12:09 sdb
brw-r----- 1 root disk 8, 32 Oct 29 12:09 sdc
brw-r----- 1 root disk 8, 48 Oct 29 12:09 sdd
brw-r----- 1 root disk 8, 64 Oct 29 12:09 sde
brw-r----- 1 root disk 8, 80 Oct 29 12:09 sdf
brw-r----- 1 root disk 8, 96 Oct 29 12:09 sdg
brw-r----- 1 root disk 8, 112 Oct 29 12:09 sdh
Of course this results in a not working failover - this should work without
using multipath at all.
After excluding the sd* devices in evms.conf it doesn't find any evms-devices
at all.
We also have a ton of
multipathd: uevent trigger error
messages in the daemon's log.
Operating system is Debian sarge, but with kernel 2.6.14, the actual git
version of the multipath-tools, evms 2.5.3, udev 0.070, libdevmapper/dmsetup
1.01.04.
Since this behaviour seems to depend on the use of the emc-hwhandler/dm-emc
I'm posting to this list.
Hope you have any ideas how to fix it, or do we run in an evms-only bug here?
Greetings from Darmstadt, Germany
Bernd Zeimetz
Darmstadt University of Technology
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