Root cause
The bug OAK-12119 is in how oak-run compact works internally:
- Offline compaction calls compactFull() and cleanup() as two separate operations.
- The CompactionResult from compactFull() was silently discarded before cleanup() ran.
- cleanup() then substituted a SKIPPED placeholder result, which has requiresGCJournalEntry() = false.
- As a result, no entry was written to gc.log after offline compaction.
- On the next two rounds of online GC, Oak's reclaimer had no knowledge of the compacted segments and began reclaiming them — causing SNFE when AEM tried to read those deleted segments.
The fix (apache/jackrabbit-oak#2779, merged March 2026) stores the CompactionResult after compaction and passes it correctly to cleanup(), ensuring gc.log is
always written.
Fix — AEM 6.5 LTS SP2
1. Install the hotfix from Software Distribution:
https://experience.adobe.com/#/downloads/content/software-distribution/en/aem.html?package=/content/software-distribution/en/details.html/content/dam/aem/public/adobe/packages/cq660/hotfixes/cq-6.5.lts.2-hotfi
x-GRANITE-65388-1.0.zip
2. For offline compaction, use the matching oak-run jar from Software Distribution:
https://experience.adobe.com/#/downloads/content/software-distribution/en/aem.html?package=/content/software-distribution/en/details.html/content/dam/aem/public/adobe/packages/cq660/hotfixes/oak-run-1.88.1-B00
6.jar
3. Add the following system property to your AEM JVM start arguments to avoid the related disk usage regression (OAK-12134):
-Doak.compaction.legacy=true
---
Fix — AEM 6.5 LTS SP1
1. Install the hotfix from Software Distribution:
https://experience.adobe.com/#/downloads/content/software-distribution/en/aem.html?package=/content/software-distribution/en/details.html/content/dam/aem/public/adobe/packages/cq660/hotfixes/cq-6.5.lts.1-hotfi
x-GRANITE-65385-1.0.zip
2. For offline compaction, use the matching oak-run jar from Software Distribution:
https://experience.adobe.com/#/downloads/content/software-distribution/en/aem.html?package=/content/software-distribution/en/details.html/content/dam/aem/public/adobe/packages/cq660/hotfixes/oak-run-1.78.1-B00
6.jar
---
Important: Always use an oak-run jar that matches the exact Oak version bundled in your AEM installation. Using a mismatched or older oak-run jar will leave gc.log unwritten and cause SNFE after the next two
online GC cycles.
References
- OAK-12119: https://issues.apache.org/jira/browse/OAK-12119
- Fix PR: https://github.com/apache/jackrabbit-oak/pull/2779
- Related disk usage regression: https://issues.apache.org/jira/browse/OAK-12134
