[dm-devel] Bug 999761 - Review NetApp path_checker and features for RHEL5 mpath

[Martin George]

On 9/3/2013 5:22 AM, Jamie Bainbridge wrote:
> Hi all,
>
> I was wondering if I could get a response on this bug?
>
>   Bug 999761 - Review NetApp path_checker and features for RHEL5 mpath
>   https://bugzilla.redhat.com/show_bug.cgi?id=999761
>
> In Bug 799842 NetApp requested that we change the default path_checker for NETAPP devices in RHEL 6.3 from directio to tur.
>
> * Would we consider changing the default hwtable in RHEL5, considering it's in Production 2?
>
> * Given NetApp reference the async tur improvements from Bug 760852 as part of their decision to use tur, is tur suitable for current RHEL5, or should we stick with directio?
>
> * If tur is suitable for current RHEL5, should we change the default RHEL5 hwtable to use tur?
>
> In Bug 799842 Comment 10 NetApp also requested we change the default features for NETAPP devices in RHEL 6.3 from "1 queue_if_no_path" to "3 queue_if_no_path pg_init_retries 50".
>
> * pg_init_retries has been in RHEL5 since 5.2, is pg_init_retries suitable for current RHEL5 also? (this seems to be an easy "yes")
>
> * If pg_init_retries is suitable for current RHEL5, should we change the default RHEL5 hwtable to use pg_init_retries?
>

On newer RHEL5 kernels like RHEL 5.9, the above changes (i.e. 'tur' path 
checker & enabling pg_init_retries) have already made it to the hwtable 
for NetApp LUNs - addressed in device-mapper-multipath-0.4.7-51.el5.

-Martin