Bug 1586189

Summary: Linux kernel configuration on s390x is missing support for SCSI Device Handlers
Product: [Fedora] Fedora Reporter: Benjamin Block <bblock>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 28CC: airlied, brueckner, bskeggs, ewk, hdegoede, ichavero, itamar, jarodwilson, jcline, jglisse, john.j5live, jonathan, josef, kernel-maint, linville, mchehab, mjg59, steved
Target Milestone: ---   
Target Release: ---   
Hardware: s390x   
OS: Linux   
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Fixed In Version: kernel-4.16.15-300.fc28 Doc Type: If docs needed, set a value
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Clone Of: Environment:
Last Closed: 2018-06-14 19:16:22 UTC Type: Bug
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Benjamin Block 2018-06-05 16:38:02 UTC 
Description of problem:

The kernel config for s390x (did not confirm whether this affects other architectures as well) is missing support for SCSI Device Handlers in Fedora 28. This is simply a config-option (CONFIG_SCSI_DH, and CONFIG_SCSI_DH_RDAC, CONFIG_SCSI_DH_HP_SW, CONFIG_SCSI_DH_EMC, CONFIG_SCSI_DH_ALUA; of which the last 4 can be build as modules). Like the help-text explains shortly, this is necessary for some storage-servers that have none-simple multipath-topologies. One such example would be IBM's Storewize storages, which make use of CONFIG_SCSI_DH_ALUA to signal which ports are active, and which passive.

When using multipathd (device-mapper-multipath), you can also see messages like this popping up in the journal:
Jun 05 18:34:52 S35LP69 modprobe[677]: modprobe: WARNING: Module scsi_dh_alua not found in directory /lib/modules/4.16.13-300.fc28.s390x
Jun 05 18:34:52 S35LP69 modprobe[677]: modprobe: WARNING: Module scsi_dh_emc not found in directory /lib/modules/4.16.13-300.fc28.s390x
Jun 05 18:34:52 S35LP69 modprobe[677]: modprobe: WARNING: Module scsi_dh_rdac not found in directory /lib/modules/4.16.13-300.fc28.s390x

And $(grep SCSI_DH /boot/config-`uname -r`) shows:
# CONFIG_SCSI_DH is not set

Version-Release number of selected component (if applicable):

4.16.13-300.fc28.s390x
Comment 1 Jeremy Cline 2018-06-05 17:45:37 UTC 
Hi Benjamin,

Those options are all enabled in the generic configuration so they've been disabled for s390x for some reason or other. I'll see about turning them on in Rawhide and Fedora 28.
Comment 2 Jeremy Cline 2018-06-05 21:22:28 UTC 
There was nothing in the logs about why it was disabled and it appears to build on s390x, so I've enabled it for Rawhide and F28. It should arrive in the tomorrow's Rawhide build and the next stable kernel build for F28. The update system will close this ticket when it arrives in F28's updates repository. Please test it out and let us know if you run into any trouble.
Comment 3 Benjamin Block 2018-06-06 08:34:37 UTC 
Thank you Jeremy.
Comment 4 Fedora Update System 2018-06-12 13:32:07 UTC 
kernel-4.16.15-300.fc28 has been submitted as an update to Fedora 28. https://bodhi.fedoraproject.org/updates/FEDORA-2018-f1b818a5c9
Comment 5 Fedora Update System 2018-06-13 04:30:53 UTC 
kernel-4.16.15-300.fc28 has been pushed to the Fedora 28 testing repository. If problems still persist, please make note of it in this bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-f1b818a5c9
Comment 6 Fedora Update System 2018-06-14 19:16:22 UTC 
kernel-4.16.15-300.fc28 has been pushed to the Fedora 28 stable repository. If problems still persist, please make note of it in this bug report.