prestodb/presto · error · UncheckedIOException

Unable to dump data to disk:

Error message

Unable to dump data to disk: 

What it means

When a Spark task overflows pages to disk (spill/dump), the dump helper collects any IOException and rethrows it as UncheckedIOException with message 'Unable to dump data to disk: '. This throw at line 1293 wraps the first (or current) IOException encountered while writing the dump, preserving suppressed exceptions.

Source

Thrown at presto-spark-base/src/main/java/com/facebook/presto/spark/execution/task/PrestoSparkTaskExecutorFactory.java:1293

                    if (ioException != exception) {
                        ioException.addSuppressed(exception);
                    }
                }
            }
            finally {
                try {
                    if (tempDataSink != null) {
                        tempDataSink.close();
                    }
                }
                catch (IOException e) {
                    if (ioException == null) {
                        ioException = e;
                    }
                    else if (ioException != e) {
                        ioException.addSuppressed(e);
                    }
                    throw new UncheckedIOException("Unable to dump data to disk: ", ioException);
                }
            }

            throw new UncheckedIOException("Unable to dump data to disk: ", ioException);
        }

        @Override
        public long getTimeSpentWaitingForOutputInMillis()
        {
            return timeSpentWaitingForOutputInMillis;
        }
    }

    private enum OutputBufferType
    {
        SPARK_ROW_OUTPUT_BUFFER,
        SPARK_PAGE_OUTPUT_BUFFER,
        SPARK_DISK_PAGE_OUTPUT_BUFFER,

View on GitHub (pinned to 55bb57d202)

Solutions

1. Check executor disk space on the spill/dump directory and free space or expand volumes
2. Verify the spill directory (e.g. spark.local.dir, presto native temp storage) exists and is writable by the Spark executor user
3. Inspect the wrapped IOException (suppressed chain) for the root cause (NoSpaceLeftOnDevice, permission denied, etc.)
4. Reduce memory pressure / increase executor memory so fewer pages spill to disk

Example fix

// check and fix spill location
// before: dumpDir defaults to a full disk
// after
if (Files.getFileStore(dumpDir).getUsableSpace() < minFreeBytes) {
    throw new PrestoException(GENERIC_INTERNAL_ERROR, "dump dir low on space: " + dumpDir);
}

long usable = Files.getFileStore(Paths.get(dumpDir)).getUsableSpace();
if (usable < requiredMinBytes) throw new PrestoException(NO_SPACE_LEFT_ON_DEVICE, "spill dir low: " + dumpDir);

boolean dumpDirWritable(Path dir) { return Files.isDirectory(dir) && Files.isWritable(dir); }

try { dumpToFile(pages); } catch (UncheckedIOException e) { Throwable root = e.getCause(); if (root instanceof IOException && root.getMessage().contains("No space left")) { alertOps("spill disk full"); } throw e; }

When it happens

Trigger: The task attempts to dump/spill data to disk (e.g. when memory is exhausted and dump-to-disk is enabled) and an IOException occurs during writing; line 1293 rethrows the recorded ioException after the loop.

Common situations: Disk full on Spark executor local directories; misconfigured spark.local.dir / spill path permissions; disk failure or read-only mount on executor nodes.

Related errors

• java.io.IOException (wrapped in UncheckedIOException)
• UNEXPECTED_ACCUMULO_ERROR
• ATOP_CANNOT_START_PROCESS_ERROR
• Failed to create Credentials from file
• BIGQUERY_ERROR_END_OF_AVRO_BUFFER

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/a5e6cb62d3e61a82. Report an issue: GitHub.