{"record":{"id":"dd2df98a62a02197","repo":"apache/hadoop","slug":"datanode-state-lv-ctime-is-newer-than-t","errorCode":null,"errorMessage":"Datanode state: LV = {} CTime = {} is newer than the namespace state: LV = {} CTime = {}","messagePattern":"Datanode state: LV = (.+?) CTime = (.+?) is newer than the namespace state: LV = (.+?) CTime = (.+?)","errorType":"exception","errorClass":"IOException","httpStatus":null,"severity":"critical","filePath":"hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockPoolSliceStorage.java","lineNumber":421,"sourceCode":"    }\n    if (this.layoutVersion == DataNodeLayoutVersion.getCurrentLayoutVersion()\n        && this.cTime == nsInfo.getCTime()) {\n      return false; // regular startup\n    }\n    if (this.layoutVersion > DataNodeLayoutVersion.getCurrentLayoutVersion()) {\n      int restored = restoreBlockFilesFromTrash(getTrashRootDir(sd));\n      LOG.info(\"Restored {} block files from trash \" +\n          \"before the layout upgrade. These blocks will be moved to \" +\n          \"the previous directory during the upgrade\", restored);\n    }\n    if (this.layoutVersion > DataNodeLayoutVersion.getCurrentLayoutVersion()\n        || this.cTime < nsInfo.getCTime()) {\n      doUpgrade(sd, nsInfo, callables, conf); // upgrade\n      return true;\n    }\n    // layoutVersion == LAYOUT_VERSION && this.cTime > nsInfo.cTime\n    // must shutdown\n    throw new IOException(\"Datanode state: LV = \" + this.getLayoutVersion()\n        + \" CTime = \" + this.getCTime()\n        + \" is newer than the namespace state: LV = \"\n        + nsInfo.getLayoutVersion() + \" CTime = \" + nsInfo.getCTime());\n  }\n\n  /**\n   * Upgrade to any release after 0.22 (0.22 included) release\n   * e.g. 0.22 =&gt; 0.23\n   * Upgrade procedure is as follows:\n   * <ol>\n   * <li>If {@literal <SD>/current/<bpid>/previous} exists then delete it</li>\n   * <li>Rename {@literal <SD>/current/<bpid>/current} to\n   * {@literal <SD>/current/bpid/current/previous.tmp}</li>\n   * <li>Create new {@literal <SD>current/<bpid>/current} directory</li>\n   * <li>Hard links for block files are created from previous.tmp to current</li>\n   * <li>Save new version file in current directory</li>\n   * <li>Rename previous.tmp to previous</li>\n   * </ol>","sourceCodeStart":403,"sourceCodeEnd":439,"githubUrl":"https://github.com/apache/hadoop/blob/2add9630210752f88ceb1bb74eb65e37bf41da8e/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockPoolSliceStorage.java#L403-L439","documentation":"The DN's block pool state is newer than the namespace: layout is not upgradable (LV not above current) and cTime is greater than the NN's — typically the DN completed an upgrade while the NN was rolled back or restored to an older state. The DN shuts down because serving newer state against an older namespace would corrupt it.","triggerScenarios":"Rolling upgrade rolled back on the NN but the DN was not rolled back; NN restored from an older image; DN storage copied from an upgraded cluster.","commonSituations":"Partial rollback procedures; downgrades attempted without rolling back every DN first.","solutions":["Restart the DN with -rollback to revert to its previous snapshot","If the rollback was itself the mistake, restore the NN to the newer namespace state instead","As a last resort for disposable data, delete this BP storage and let the DN re-register"],"exampleFix":"# before\nhdfs --daemon start datanode          # throws: newer than namespace\n\n# after\nhdfs --daemon start datanode -rollback","handlingStrategy":"retry","validationCode":null,"typeGuard":null,"tryCatchPattern":"catch (IOException e) {\n  if (e.getMessage().contains(\"is newer than the namespace state\")) {\n    // correct fix: restart this DN with -rollback\n    haltForOperator(\"restart datanode with -rollback\");\n  }\n}","preventionTips":["When rolling back a rolling upgrade, roll back every DataNode, not just some","Never downgrade an NN while DNs still hold upgraded state"],"tags":["hdfs","datanode","storage","ctime","rollback-mismatch"],"backgroundTag":"storage-ctime-mismatch","analyzedSha":"2add9630210752f88ceb1bb74eb65e37bf41da8e","analyzedAt":"2026-08-22T19:55:07.957Z","schemaVersion":2},"datasetVersion":"2026-08-23T01:17:44.959Z"}