[CQ/AEM] SegmentNotFoundException

Issue:
When we see the error "org.apache.jackrabbit.oak.plugins.segment.SegmentNotFoundException: Segment 6e0a804f-0d75-48a8-a579-ebf34e58e763 not found" one day, and you can not open any pages, or can access neither crx nor console.

Solution:
We can use oak runnable to check and restore the last good revision into Oak's working directory.

Tool: Oak-run Tool (http://mvnrepository.com/artifact/org.apache.jackrabbit/oak-run)

Check more from http://cqhints.blogspot.com/2015/07/cq6-system-maintaining-repository.html

Step to restore Oak's working directory:
1. Backup all files in ./crx-quickstart/repository/segmentstore/.

2. Run the consistency check

java -jar oak-run-*.jar check -d1 --bin=-1 -p crx-quickstart/repository/segmentstore/

It will search backwards through the revisions until it finds a consistent one:
18:01:51.336 [main] INFO o.a.j.o.p.s.f.t.ConsistencyChecker - Found latest good revision ca9c71ae-1941-4a2d-aaed-c444db7a4c6d:260120

3. Revert the repository to this revision by editing ./crx-quickstart/repository/segmentstore/journal.log and deleting all lines after the line containing the latest good revision.

4. Remove all ./crx-quickstart/repository/segmentstore/*.bak files.

5. Run checkpoint clean-up to remove orphaned checkpoints:

java -jar oak-run-*.jar checkpoints ./crx-quickstart/repository/segmentstore rm-unreferenced

6. Finally compact the repository:

java -jar oak-run-*.jar compact ./crx-quickstart/repository/segmentstore/