Latest revision as of 20:00, 11 May 2026

Introduction

The virtual PTG for the 2026.2 (Hibiscus) cycle of Cinder was conducted from Monday, 20th April, 2026 to Friday, 24th April, 2026 (virtual). This page provides a summary of all the topics discussed throughout the PTG.

Summary

2026.1 Gazpacho Retrospective

• Every release deadline was missed by a few days (including client libraries and os-brick).
• Agreement to be stricter about release deadlines and send explicit deadline reminders.
• No concrete solution yet for prioritizing reviews to ease deadline pressure.

2026.2 Release Planning

• Discussion of adding Cinder-specific entries to the Hibiscus release schedule.
• Contributor documentation needs updating: deliverables list, meeting cadence (resume monthly video meeting), and explicit os-brick readiness dates.
• Add a "new driver declaration deadline" early in the cycle to allow time for review planning.
• Action: agalica to review contributor docs for clarity and correctness.
• Action: jbernard to consider moving the review festival to a single block after the weekly meeting.

Scheduler Sending Jobs to Disabled Hosts (zigo)

• Patch under review: !979641.
• Reviewers need a bug filed with more detail to understand the fix; a possible race condition is suspected.
• Patch needs unit tests. The question of whether "frozen" hosts are also affected needs investigation.

Supply WWID Instead of LUN Numbers (rajat)

• Current iSCSI/FC logic uses LUN numbers, which can change or overlap under certain conditions.
• Proposal: use WWID (which is stable for the lifetime of a LUN) instead, with LUN-based code kept as a fallback.
• Drivers will need updates; strategy is to start with the LVM driver (LIO target) for iSCSI.
• A tempest test should be added to enforce the new contract, with a grace period of a couple of cycles for vendor CIs.
• Action: rajat to send a message to the mailing list for vendor feedback.

New Driver Status (erlon)

Three new drivers are currently in review for Hibiscus:

• ZTE: !969207
• LINSTOR: !964289
• HPE Alletra MP: !969373

Goal is to compile a driver list early in the cycle to direct review resources appropriately.

RBD Encryption Performance (rsasitilak)

• Proposal to use the librbd engine to bypass the QEMU single-thread bottleneck during encrypted volume I/O.
• Skepticism about the performance improvement claims and the level of rework required to the current RBD implementation.
• Action: jbernard to respond to the mailing list thread requesting more detailed benchmarking information.

Volume Migration with Snapshots (fqi)

• Currently, migrating a volume that has snapshots fails.
• Proposal to query drivers for available functionality and use it when present, broken into three stages.
• Blueprint: volume-migration-with-snapshot
• Open questions remain around snapshot semantics (snapshots becoming separate volumes) and vendor-specific COW implementations.

HPE Alletra MP Driver (Jyotsna/raghavendrat)

• New driver in review: !969373.
• Uses the hpe-storage-flowkit-py library as an intermediary layer to separate backend-specific logic from driver code.

Backup Container Name Templates (noonedeadpunk)

• Spec: !962306; patch: !962909.
• Key concern: when the template changes in config, operators must manually migrate existing backup data.
• Discussion of adding a DB field to track the actual (post-template) container name separately from the configured value.

CBT-Based Incremental Backup (hong-p)

• Spec: !985089.
• Proposal to optimize incremental backups using Changed Block Tracking (CBT).
• Nova involvement required for attached volumes; Cinder implementation useful for bare-metal attachments.
• No philosophical objections from the team; free to proceed. Open questions include where to store CBT data and the need for an external REST API.

Logging Guidelines (Anoop_Shukla / NetApp)

• Proposal for a dedicated logging best-practices document for Cinder driver authors, covering log level definitions and usage of the @volume_utils.trace decorator.
• Working document: OpenStack Cinder Logging Guidelines etherpad.
• Seeking community feedback.

RBD Performance: Direct Import (ricolin)

Using QEMU to output directly rather than rbd import yields at least a 20% I/O performance improvement for large (>1 TB) volumes, including encrypted volumes. Relevant patches:

• Non-encrypted: !972263
• Encrypted (direct import): !933006
• Encrypted (direct volume creation): !910700
• Alternative encrypted approach (rajat): !955273

Replication v3 (rajat)

• Spec: !985952.
• Extends replication to support finer-grained failover (per-volume, per-pool, per-backend).
• Includes automation of failover for synchronous replication and cross-cluster failover with security guards.
• Safeguards needed to prevent overlap between replication granularities.

3rd-Party CI Systems (simondodsley)

• Current tooling (SoftwareFactory moving to OpenShift) is not sustainable for all vendors.
• Proposal to create a standard, simple CI template for running Cinder and os-brick tests, reporting to Gerrit, and storing logs in a GitHub repository with a standard URL format.

NetApp Topics (jayanan)

• Per-pool image cache enhancements.
• Replication over Fibre Channel.
• Best practices for raising dependent patches (noted: git-restack tool).
• ONTAP REST vs. ZAPI migration gaps.

Friday Patch Review

• General patch review session.
• Kubernetes lock support patch flagged for attention: !956528.