apache/hadoop · error · UnsupportedOperationException

ACLs not supported by ImageWriter

Error message

ACLs not supported by ImageWriter

What it means

Error "ACLs not supported by ImageWriter" thrown in apache/hadoop.

Source

Thrown at hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/TreePath.java:162

        .setReplication(blk.getReplication(s))
        .setModificationTime(s.getModificationTime())
        .setAccessTime(s.getAccessTime())
        .setPreferredBlockSize(blk.preferredBlockSize(s))
        .setPermission(permissions)
        .setStoragePolicyID(HdfsConstants.PROVIDED_STORAGE_POLICY_ID);

    // pathhandle allows match as long as the file matches exactly.
    PathHandle pathHandle = null;
    if (fs != null) {
      try {
        pathHandle = fs.getPathHandle(s, Options.HandleOpt.exact());
      } catch (UnsupportedOperationException e) {
        LOG.warn(
            "Exact path handle not supported by filesystem " + fs.toString());
      }
    }
    if (aclStatus != null) {
      throw new UnsupportedOperationException(
          "ACLs not supported by ImageWriter");
    }
    //TODO: storage policy should be configurable per path; use BlockResolver
    long off = 0L;
    for (BlockProto block : blk.resolve(s)) {
      b.addBlocks(block);
      writeBlock(block.getBlockId(), off, block.getNumBytes(),
          block.getGenStamp(), pathHandle, out);
      off += block.getNumBytes();
    }
    INode.Builder ib = INode.newBuilder()
        .setType(INode.Type.FILE)
        .setId(id)
        .setName(ByteString.copyFrom(string2Bytes(s.getPath().getName())))
        .setFile(b);
    return ib.build();
  }

View on GitHub (pinned to 2add963021)

Solutions

1. Strip ACLs from the input (do not use -getfacl output with ACLs) or extend ImageWriter to serialize ACLs; the writer rejects them.

When it happens

Trigger: The input path carries ACL entries while ImageWriter is configured in a mode that does not support writing ACLs into the generated fsimage.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/e835b645347f4f72. Report an issue: GitHub.