apache/hadoop · error · HadoopIllegalArgumentException

Snapshot name cannot contain "/"

Error message

Snapshot name cannot contain "/"

What it means

Error "Snapshot name cannot contain "/"" thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirSnapshotOp.java:56

import org.apache.hadoop.util.Time;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

class FSDirSnapshotOp {
  public static final Logger LOG =
      LoggerFactory.getLogger(FSDirSnapshotOp.class);

  /** Verify if the snapshot name is legal. */
  static void verifySnapshotName(FSDirectory fsd, String snapshotName,
      String path)
      throws FSLimitException.PathComponentTooLongException {
    if (snapshotName.contains(Path.SEPARATOR)) {
      throw new HadoopIllegalArgumentException(
          "Snapshot name cannot contain \"" + Path.SEPARATOR + "\"");
    }
    final byte[] bytes = DFSUtil.string2Bytes(snapshotName);
    fsd.verifyINodeName(bytes);
    fsd.verifyMaxComponentLength(bytes, path);
  }

  /** Allow snapshot on a directory. */
  static void allowSnapshot(FSDirectory fsd, SnapshotManager snapshotManager,
                            String path) throws IOException {
    fsd.writeLock();
    try {
      snapshotManager.setSnapshottable(path, true);
    } finally {
      fsd.writeUnlock();
    }
    fsd.getEditLog().logAllowSnapshot(path);
  }

View on GitHub (pinned to 2add963021)

Solutions

1. Use a snapshot name without '/' characters, e.g. 'snap1' instead of 'a/b'.

When it happens

Trigger: Creating or renaming a snapshot with a name containing the path separator character '/'.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/953f13808d900ffb. Report an issue: GitHub.