Bug 695435

Summary:	Implement more intelligent scsi_dh module attachment
Product:	Red Hat Enterprise Linux 6	Reporter:	Mike Christie <mchristi>
Component:	kernel	Assignee:	Mike Christie <mchristi>
Status:	CLOSED DUPLICATE	QA Contact:	Storage QE <storage-qe>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	6.2	CC:	agk, bdonahue, berthiaume_wayne, bmarzins, bmr, christophe.varoqui, dwysocha, heinzm, hicks_verdell, junichi.nomura, kchoi, kueda, kzhang, levy_jerome, lmb, mbelangia, mbroz, mchristi, mgoodwin, msnitzer, prajnoha, prockai, qcai, rmitchel, sawickig
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	666304	Environment:
Last Closed:	2011-11-03 15:16:17 UTC	Type:	---
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:	666304
Bug Blocks:

Comment 1 Mike Christie 2011-04-11 18:14:10 UTC

This bz is for implementing more intelligent scsi_dh attachment. Today, it is based on which scsi_dh module is loaded first.

For Clarrions we want to do below. We will want to do something similar for other boxes that support vendor specific methods and ALUA.


In the standard inquiry return, byte 5 bits 4 and 5 (zero-relative) contain the
TPGS status. They'll be 00 on a PNR array and 11 on an ALUA box. The lun_state
information can be ambiguous as 0x01 and 0x02 are returned in both ALUA and PNR
modes but means different things;

0x01 (PNR)  LUN bound and assigned to the OTHER SP 
0x01 (ALUA) LUN bound and using the non-optimized path

0x02 (PNR)  LUN bound and assigned to THIS SP 
0x02 (ALUA) LUN bound and using the optimized path 

So I'd say we check TPGS first and then we can interpret the lun_state
accordingly based on that info...

Comment 2 RHEL Program Management 2011-05-13 15:26:07 UTC

This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux maintenance release. Product Management has 
requested further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed 
products. This request is not yet committed for inclusion in an Update release.

Comment 4 Mike Snitzer 2011-11-03 15:16:17 UTC


*** This bug has been marked as a duplicate of bug 690523 ***