I/O Trace Data Files

The following traces are free to download under the terms of the SNIA Trace Data Files Download License. Please note that cookies must be enabled within your browser in order to download traces.

The "Download Traces FAQs" provide information about the overall requirements and the procedure associated with downloading I/O Trace Data files from the IOTTA Repository.

We also have a spreadsheet containing information on some currently known traces.


The I/O Trace Data files have been segregated into several broad categories. These categories are typically, although not exclusively, defined by the measurement point at which the respective I/O trace was taken.

The categories (or types) of I/O traces include:

  • Application Traces [This category is currently empty]
    Application Traces record calls made by a specific application.
  • Block I/O Traces
    Block I/O Traces typically include block level (e.g., at the logical volume manager, disk driver, etc. level) and block protocol (e.g., SCSI, ATA, Fibre Channel) traces.
  • HPC Summaries
    Traces from HPC installations, generally expressed as statistical summaries rather than blow-by-blow event traces
  • Key-Value Traces
    Key-Value traces reflect activity directed to key-value stores.

    Related traces can also be found in the Parallel Traces section.

  • NFS Traces
    Network File System Traces are typically those for NFS and CIFS and which reflect the protocol used by such network file systems.
  • Parallel Traces
    Parallel traces, generally taken from supercomputers or in large datacenters, record activity from multiple computers running in parallel.

    Similar traces can also be found in the Key-Value Traces section.

  • Reliability Traces
    Records of storage system reliability, for example long-term records of hard-drive failures.
  • Static Snapshots
    Static Snapshots are traces taken statically of a file system rather than of system calls.
  • System Call Traces
    System-Call I/O Traces typically reflect operating system calls to the file system.

    Some system-call traces can also be found in the Parallel Traces section.

  • Workload Summaries
    Workload summaries contain statistical summaries of workload characteristics. They are typically collected over repeated medium-term time periods, such as every hour, and summarize the operations that were observed during that time.

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