Bug 2065477

Summary: [RFE] enable device configuration selection to include the transport protocol.
Product: Red Hat Enterprise Linux 8 Reporter: Lance Digby <ldigby>
Component: device-mapper-multipathAssignee: Ben Marzinski <bmarzins>
Status: CLOSED ERRATA QA Contact: Lin Li <lilin>
Severity: medium Docs Contact: Renata Harcarikova <rharcari>
Priority: medium    
Version: 8.5CC: agk, bmarzins, heinzm, jmagrini, lilin, msnitzer, nyewale, prajnoha, rmadhuso, zkabelac
Target Milestone: rcKeywords: FutureFeature, Triaged
Target Release: ---Flags: pm-rhel: mirror+
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: device-mapper-multipath-0.8.4-24.el8 Doc Type: Enhancement
Doc Text:
.`multipath.conf` can now include protocol-specific configuration overrides in DM Multipath You can access paths of multipath devices through various protocols. Because various protocols can have various optimal configurations, it was previously not possible to set the optimal configuration for all protocols in the Device Mapper Multipath feature without a per-protocol option. With this enhancement, you can include protocol-specific configuration overrides in the `multipath.conf` file. As a result, you can now configure multipath device paths on a per-protocol basis, allowing for the correct configuration of multipath devices accessible through multiple protocols.
Story Points: ---
Clone Of:
: 2084365 (view as bug list) Environment:
Last Closed: 2022-11-08 10:47:39 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:    
Bug Blocks: 2084365    

Comment 4 Ben Marzinski 2022-05-17 18:28:02 UTC
The final solution to to is to add a protocol subsection to the overrides section of multipath.conf, which can contain multiple protocol subsections. Path devices are matched against the protocol subsection using the mandatory "type" attribute.  Attributes in a matching protocol subsection take precedence over attributes in the rest
of the overrides section, which like always take precedence of attributes in the devices and defaults sections. If there are multiple matching protocol subsections, later entries take precedence. The "type" attribute can be one of scsi:fcp, scsi:spi, scsi:ssa, scsi:sbp, scsi:srp, scsi:iscsi, scsi:sas, scsi:adt, scsi:ata, scsi:unspec, ccw, cciss, nvme, and undef. The protocol that a path is using can be viewed by running:

multipathd show paths format "%d %P"

The only attributes that can be set in the protocol subsection are "type", "dev_loss_tmo", "fast_io_fail_tmo", and "eh_deadline". Here is an example of a overrides sections with protocol subsections:

overrides {
        protocol {
                type "scsi:fcp"
                dev_loss_tmo 70
                fast_io_fail_tmo 10
                eh_deadline 360
        }
        protocol {
                type "scsi:iscsi"
                fast_io_fail 120
        }
}

Comment 16 errata-xmlrpc 2022-11-08 10:47:39 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 (device-mapper-multipath bug fix and enhancement update), 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://access.redhat.com/errata/RHBA-2022:7714