Virtual Object Layer

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	https://github.com/hpc-io/vol-async	Suren Byna (sbyna at lbl dot gov)
Cache	513	cache	Provides support for multi-level, multi-location data caching to dataset I/O operations	https://github.com/hpc-io/vol-cache	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.	https://github.com/DataLib-ECP/vol-log-based/blob/master/README.md	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 https://doi.org/10.1109/TPDS.2021.3097884	https://github.com/HDFGroup/vol-daos 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	https://github.com/hpc-io/vol-external-passthrough	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.	https://github.com/hpc-io/vol-dset-split	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	https://github.com/hpc-io/pdc https://github.com/hpc-io/vol-pdc	Houjun Tang (htang4 at lbl dot gov)
REST	520	REST	Designed to utilize web-based storage systems by use of the HDF5 REST APIs	https://github.com/HDFGroup/vol-rest	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.	https://github.com/diatomic/LowFive	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	https://github.com/HDFGroup/vol-rados	help at hdfgroup dot org

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