Bug 1299652

Summary: Make alua prioritizer able to exclusively use the preferred path, if available
Product: Red Hat Enterprise Linux 7 Reporter: Ben Marzinski <bmarzins>
Component: device-mapper-multipathAssignee: Ben Marzinski <bmarzins>
Status: CLOSED ERRATA QA Contact: Zhang Yi <yizhan>
Severity: unspecified Docs Contact: Milan Navratil <mnavrati>
Priority: unspecified    
Version: 7.1CC: agk, bmarzins, dwysocha, hartsjc, heinzm, lilin, mnavrati, msnitzer, prajnoha, prockai, rbalakri, rweiss, slevine, zkabelac
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: device-mapper-multipath-0.4.9-87.el7 Doc Type: Release Note
Doc Text:
The "exclusive_pref_bit" optional argument has been added to the *multipath* ALUA prioritizer If the "exclusive_pref_bit" argument is added to the *multipath* Asymmetric Logical Unit Access (ALUA) prioritizer, and a path has the Target Port Group Support (TPGS) `pref` bit set, *multipath* makes a path group using only that path and assigns the highest priority to the path. Users can now either allow the preferred path to be in a path group with other paths that are equally optimized, which is the default option, or in a path group by itself by adding the "exclusive_pref_bit" argument.
Story Points: ---
Clone Of: 1289353
: 1364188 (view as bug list) Environment:
Last Closed: 2016-11-04 08:17:04 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1289353, 1305997    
Bug Blocks: 1295577, 1313485, 1364188    

Comment 1 Ben Marzinski 2016-02-26 22:56:11 UTC
The multipath alua prioritizer now allows a an option, "exclusive_pref_bit"

If you use

    prio "alua exclusive_pref_bit"

in your device configuration, multipath will create a pathgroup that only contains the path with the pref bit set, and will give that pathgroup the highest priority.

Comment 2 Ben Marzinski 2016-03-17 21:23:14 UTC
Oops. Comment 1 used the RHEL6 syntax.  In RHEL7, you would add

prio_args "exclusive_pref_bit"

to your device configuration. This is only used if you have

prio "alua"

set as well.

Comment 12 errata-xmlrpc 2016-11-04 08:17:04 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-2536.html