OSDOCS#19052: Add z-stream release notes 4.20.18 by aksjoshi89 · Pull Request #109901 · openshift/openshift-docs

aksjoshi89 · 2026-04-09T19:26:15Z

Version(s):
4.20

Issue:
OSDOCS-19052

Link to docs preview:
https://109901--ocpdocs-pr.netlify.app/openshift-enterprise/latest/release_notes/ocp-4-20-release-notes.html#zstream-4-20-18_release-notes

QE review:
N/A

Additional information:
ART Dashboard Link:
https://art-dash.engineering.redhat.com/dashboard/release/openshift-4.20

Shipment Link:
https://gitlab.cee.redhat.com/hybrid-platforms/art/ocp-shipment-data/-/merge_requests/460/diffs#2b6b42520029cfef031e3f171793167d2c4e9531

ocpdocs-previewbot · 2026-04-09T19:34:44Z

🤖 Tue Apr 14 14:33:31 - Prow CI generated the docs preview:

https://109901--ocpdocs-pr.netlify.app/openshift-enterprise/latest/release_notes/ocp-4-20-release-notes.html

ocpdocs-vale-bot · 2026-04-09T19:35:53Z

modules/zstream-4-20-18.adoc

+
+* Before this release, global navigation satellite system (GNSS) serial port auto-detection issue in the grandmaster file caused GNSS port index changes after reboot, leading to node time synchronization issues. To work around this problem, remove `ts2phc.nmea_serialport` from the grandmaster `PTPConfig` and reboot the node. As a result, the GNSS port index number is no longer change after reboot, preventing time synchronization issues. (link:https://redhat.atlassian.net/browse/OCPBUGS-77749[OCPBUGS-77749])
+
+* Before this update, insufficient /var/`ostree-container` partition size triggered image pull failure. As a consequence, end user deployment on Power using UPI and network boot failed due to insufficient partition size. With this release, the size of /var/`ostree-container` mount is increased to 5GB. As a result, image pull issues are resolved, improving deployment. (link:https://redhat.atlassian.net/browse/OCPBUGS-77896[OCPBUGS-77896])


🤖 [error] RedHat.TermsErrors: Use 'user' rather than 'end user'. For more information, see RedHat.TermsErrors.

ocpdocs-vale-bot · 2026-04-09T19:35:54Z

modules/zstream-4-20-18.adoc

+
+* Before this release, global navigation satellite system (GNSS) serial port auto-detection issue in the grandmaster file caused GNSS port index changes after reboot, leading to node time synchronization issues. To work around this problem, remove `ts2phc.nmea_serialport` from the grandmaster `PTPConfig` and reboot the node. As a result, the GNSS port index number is no longer change after reboot, preventing time synchronization issues. (link:https://redhat.atlassian.net/browse/OCPBUGS-77749[OCPBUGS-77749])
+
+* Before this update, insufficient /var/`ostree-container` partition size triggered image pull failure. As a consequence, end user deployment on Power using UPI and network boot failed due to insufficient partition size. With this release, the size of /var/`ostree-container` mount is increased to 5GB. As a result, image pull issues are resolved, improving deployment. (link:https://redhat.atlassian.net/browse/OCPBUGS-77896[OCPBUGS-77896])


🤖 [error] RedHat.TermsErrors: Use 'user-provisioned infrastructure' rather than 'UPI'. For more information, see RedHat.TermsErrors.

ocpdocs-vale-bot · 2026-04-09T19:35:57Z

modules/zstream-4-20-18.adoc

+
+* Before this update, the slow refresh interval of OVN `EgressFirewall` Domain Name System (DNS) resolution caused a synchronization gap between the application's DNS resolution and the firewall controller's update cycle. As a consequence, slow DNS resolution in OVN egress firewall caused delay for application access after Network Load Balancer (NLB) recreation. With this release, the `EgressFirewall` DNS refresh interval has been adjusted for faster resolution. As a result, the `EgressFirewall` DNS resolution delay is reduced, improving the application's responsiveness. (link:https://redhat.atlassian.net/browse/OCPBUGS-79537[OCPBUGS-79537])
+
+* Before this update, a nil pointer dereference occurred in the `sortUnpackJobs` function when sorting non-failed jobs. As a consequence, the catalog-operator Pod crashed during {sno} cluster installation, causing Operator installation failure. With this release, the nil pointer dereference is fixed, improving stability. As a result, the `catalog-operator` does not crash during {sno} cluster installation, ensuring smooth Operator installation. (link:https://redhat.atlassian.net/browse/OCPBUGS-79681[OCPBUGS-79681])


🤖 [error] Vale.Terms: Use 'Operators?' instead of 'operator'.

ocpdocs-vale-bot · 2026-04-09T19:35:59Z

modules/zstream-4-20-18.adoc

+
+* Before this update, a nil pointer dereference occurred in the `sortUnpackJobs` function when sorting non-failed jobs. As a consequence, the catalog-operator Pod crashed during {sno} cluster installation, causing Operator installation failure. With this release, the nil pointer dereference is fixed, improving stability. As a result, the `catalog-operator` does not crash during {sno} cluster installation, ensuring smooth Operator installation. (link:https://redhat.atlassian.net/browse/OCPBUGS-79681[OCPBUGS-79681])
+
+* Before this update, the old {IBM Cloud} `vpc-go-sdk` version was unable to process `SecurityGroup` Rules with 'any' protocol, causing machine creation failures due to incompatibility with new Virtual Private Cloud (VPC) Security Group Rule. With this release, the VPC go Software Development Kit (SDK) has been updated to resolve the Security Group rule issue, allowing new `MachineSet` creation. As a result, the updated VPC Go SDK resolves the Security Group rule creation issue, enabling a new `MachineSet` to be provisioned without errors. (link:https://redhat.atlassian.net/browse/OCPBUGS-81317[OCPBUGS-81317])


🤖 [error] OpenShiftAsciiDoc.SuggestAttribute: Use the AsciiDoc attribute '{ibm-cloud-title}' rather than the plain text product term 'IBM Cloud', unless your use case is an exception.

ocpdocs-vale-bot · 2026-04-09T19:36:00Z

modules/zstream-4-20-18.adoc

+[id="zstream-4-20-18-updating_{context}"]
+== Updating
+
+To update an {product-title} 4.20 cluster to this latest release, see xref:../updating/updating_a_cluster/updating-cluster-cli.adoc#updating-cluster-cli[Updating a cluster using the CLI].


🤖 [error] OpenShiftAsciiDoc.NoXrefInModules: Do not include xrefs in modules, only assemblies (exception: release notes modules).

dfitzmau

Hi, @aksjoshi89 . Nice work. I added comments, where some might need bug reporter input or a scan of the bug text.

modules/zstream-4-20-18.adoc

dfitzmau · 2026-04-10T09:13:26Z

modules/zstream-4-20-18.adoc

+
+* Before this release, global navigation satellite system (GNSS) serial port auto-detection issue in the grandmaster file caused GNSS port index changes after reboot, leading to node time synchronization issues. To work around this problem, remove `ts2phc.nmea_serialport` from the grandmaster `PTPConfig` and reboot the node. As a result, the GNSS port index number is no longer change after reboot, preventing time synchronization issues. (link:https://redhat.atlassian.net/browse/OCPBUGS-77749[OCPBUGS-77749])
+
+* Before this update, insufficient /var/`ostree-container` partition size triggered image pull failure. As a consequence, end user deployment on Power using UPI and network boot failed due to insufficient partition size. With this release, the size of /var/`ostree-container` mount is increased to 5GB. As a result, image pull issues are resolved, improving deployment. (link:https://redhat.atlassian.net/browse/OCPBUGS-77896[OCPBUGS-77896])


Suggested change

* Before this update, insufficient /var/`ostree-container` partition size triggered image pull failure. As a consequence, end user deployment on Power using UPI and network boot failed due to insufficient partition size. With this release, the size of /var/`ostree-container` mount is increased to 5GB. As a result, image pull issues are resolved, improving deployment. (link:https://redhat.atlassian.net/browse/OCPBUGS-77896[OCPBUGS-77896])

* Before this update, insufficient `/var/ostree-container` partition size triggered image pull failure. As a consequence, an end-user deployment that runs on user-provisioned infrastructure for IBM Power and network boot failed due to insufficient partition size. With this release, the size of `/var/ostree-container` mount is increased to 5GB. As a result, image pull issues are resolved, improving deployment. (link:https://redhat.atlassian.net/browse/OCPBUGS-77896[OCPBUGS-77896])

This note is confusing. Power = IBM Power? If so (confirm with bug reporter), the attribute is {ibm-power-title}.

Why is the deployment running on "Power"

Some parts of this are not fixed:

/var/ostree-container should be surrounded by backticks -> /var/ostree-container

modules/zstream-4-20-18.adoc

aksjoshi89 · 2026-04-14T14:26:29Z

/label merge-review-needed

openshift-ci · 2026-04-14T14:34:33Z

@aksjoshi89: all tests passed!

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openshift-ci bot added the size/M Denotes a PR that changes 30-99 lines, ignoring generated files. label Apr 9, 2026

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aksjoshi89 changed the title ~~OSDOCS#xx: Add z-stream release notes 4.20.18~~ OSDOCS#19052: Add z-stream release notes 4.20.18 Apr 10, 2026

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Add z-stream release notes 4.20.18

456bb0a

aksjoshi89 force-pushed the z-stream-4.20.18 branch from 30c72d8 to 456bb0a Compare April 14, 2026 14:26

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dfitzmau merged commit 4c2da86 into openshift:enterprise-4.20 Apr 14, 2026
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		* Before this release, global navigation satellite system (GNSS) serial port auto-detection issue in the grandmaster file caused GNSS port index changes after reboot, leading to node time synchronization issues. To work around this problem, remove `ts2phc.nmea_serialport` from the grandmaster `PTPConfig` and reboot the node. As a result, the GNSS port index number is no longer change after reboot, preventing time synchronization issues. (link:https://redhat.atlassian.net/browse/OCPBUGS-77749[OCPBUGS-77749])

		* Before this update, insufficient /var/`ostree-container` partition size triggered image pull failure. As a consequence, end user deployment on Power using UPI and network boot failed due to insufficient partition size. With this release, the size of /var/`ostree-container` mount is increased to 5GB. As a result, image pull issues are resolved, improving deployment. (link:https://redhat.atlassian.net/browse/OCPBUGS-77896[OCPBUGS-77896])


		* Before this update, the slow refresh interval of OVN `EgressFirewall` Domain Name System (DNS) resolution caused a synchronization gap between the application's DNS resolution and the firewall controller's update cycle. As a consequence, slow DNS resolution in OVN egress firewall caused delay for application access after Network Load Balancer (NLB) recreation. With this release, the `EgressFirewall` DNS refresh interval has been adjusted for faster resolution. As a result, the `EgressFirewall` DNS resolution delay is reduced, improving the application's responsiveness. (link:https://redhat.atlassian.net/browse/OCPBUGS-79537[OCPBUGS-79537])

		* Before this update, a nil pointer dereference occurred in the `sortUnpackJobs` function when sorting non-failed jobs. As a consequence, the catalog-operator Pod crashed during {sno} cluster installation, causing Operator installation failure. With this release, the nil pointer dereference is fixed, improving stability. As a result, the `catalog-operator` does not crash during {sno} cluster installation, ensuring smooth Operator installation. (link:https://redhat.atlassian.net/browse/OCPBUGS-79681[OCPBUGS-79681])


		* Before this update, a nil pointer dereference occurred in the `sortUnpackJobs` function when sorting non-failed jobs. As a consequence, the catalog-operator Pod crashed during {sno} cluster installation, causing Operator installation failure. With this release, the nil pointer dereference is fixed, improving stability. As a result, the `catalog-operator` does not crash during {sno} cluster installation, ensuring smooth Operator installation. (link:https://redhat.atlassian.net/browse/OCPBUGS-79681[OCPBUGS-79681])

		* Before this update, the old {IBM Cloud} `vpc-go-sdk` version was unable to process `SecurityGroup` Rules with 'any' protocol, causing machine creation failures due to incompatibility with new Virtual Private Cloud (VPC) Security Group Rule. With this release, the VPC go Software Development Kit (SDK) has been updated to resolve the Security Group rule issue, allowing new `MachineSet` creation. As a result, the updated VPC Go SDK resolves the Security Group rule creation issue, enabling a new `MachineSet` to be provisioned without errors. (link:https://redhat.atlassian.net/browse/OCPBUGS-81317[OCPBUGS-81317])

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