[dm-devel] I/O error during path failover

[Edward Goggin]

On Sunday, November 26, 2006 8:27 AM, Petteri Heinonen wrote

> I have a system with Qlogic QLA2312 HBAs. System is running RHEL 4u4:
> 
> [root at cpn-0 etc]# uname -a
> Linux cpn-0.chas1A.ucs2.net 2.6.9-42.ELsmp #1 SMP Wed Jul 12 
> 23:27:17 EDT 2006 i686 i686 i386 GNU/Linux
> [root at cpn-0 etc]# rpm -qa | grep device
> device-mapper-1.02.07-4.0.RHEL4
> device-mapper-multipath-0.4.5-18.1.RHEL4
> [root at cpn-0 etc]#
> 
> Storage is EMC Cx500. Multipath.conf is at the end of the 
> mail. I have tested the system by running I/O directly to 
> multipath device file, e.g. like this:
> 
> dd if=/dev/mpath/dm-0 of=/dev/null count=10000000
> 
> Now, when I pull the cable to cause path change, dd usually 
> stops in the middle, and gives error message indicating I/O 
> error. Any suggestions?
>

The CLARiiON should only be configured with a dm-multipath path
grouping policy of "group_by_prio".

Using a no_path_retry value of "fail" may prevent a CLARiiON ucode
from being updated in an application transparent manner.  Should set
CLARiiON features to "1 queue_if_no_path".