The HDF Group


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Visualization of an HDF5 file
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Registered VOL Connectors

Members of the HDF5 users community can register VOL connectors for use with HDF5. To register a VOL connector please contact The HDF Helpdesk with the following information:

Here is the current policy regarding VOL connector identifier assignment: Valid VOL connector identifiers can have values from 0 through 255 for connectors defined by the HDF5 library. Values 256 through 511 are available for testing new VOL connectors. Subsequent values should be obtained by contacting the The HDF Help Desk.

Please contact the maintainer of a VOL connector for help implementing the plugin.

List of VOL Connectors Registered with The HDF Group

Connector Connector Identifier Search Name* Short Description URL Contacts
Asynchronous I/O 512 async Provides support for asynchronous operations to HDF5 Suren Byna (sbyna at lbl dot gov)
Cache 513 cache Provides support for multi-level, multi-location data caching to dataset I/O operations Suren Byna (sbyna at lbl dot gov)
Log-based 514 LOG The log-based VOL plugin stores HDF5 datasets in a log-based storage layout.
In this layout, data of multiple write requests made by an MPI process are appended one after another in the file. Such I/O strategy can avoid the expensive inter-process communication and I/O serialization due to file lock contentions when storing data in the canonical order. Through the log-based VOL, existing HDF5 programs can achieve a better parallel write performance with minimal changes to their codes. Kai Yuan Hou
(khl7265 at ece dot northwestern dot edu)
DAOS 4004 daos Designed to utilize the DAOS object storage system by use of the DAOS API
HDF5 DAOS VOL Connector Design
HDF5 DAOS VOL Connector User’s Guide
help at hdfgroup dot org
native 0 native     help at hdfgroup dot org
pass-through 517 pass_through_ext Provides a simple example of a pass-through VOL connector Suren Byna (sbyna at lbl dot gov)
dset-split 518 dset-split Creates separate sub files for each dataset created and mounts these sub-files as external links in the main file. It enables versioning of HDF5 files at a dataset boundary. Annmary Justine (annmary dot roy at hpe dot com)
PDC-VOL 519 PDC-VOL It is a terminal VOL that reads and writes HDF5 objects to the PDC system Houjun Tang (htang4 at lbl dot gov)
REST 520 REST Designed to utilize web-based storage systems by use of the HDF5 REST APIs Matthew Larson (mlarson at hdfgroup dot org)
LowFive 521 LowFive A new data transport layer based on the HDF5 data model, for in situ workflows. Executables using LowFive can communicate in situ (using in-memory data and MPI message passing), reading and writing traditional HDF5 files to physical storage, and combining the two modes. Tom Peterka (tpeterka at mcs dot anl dot gov)
Dmitriy Morozov (dmorozov at lbl dot gov)

*The Search Name provides a mechanism for searching for a VOL.

List of Prototype VOL Connectors

Connector Connector Identifier Search Name* Short Description URL Contacts
rados unassigned rados Prototype VOL connector to access data in RADOS help at hdfgroup dot org

*The Search Name provides a mechanism for searching for a VOL.