Cloud Data Research Archive (CDRA) Storage Service

With the continual growth of data, it has been a burden for researchers to maintain all of the research data, especially data not in active use.  To address this archival need, ITS works out a solution based on public cloud service to eliminate the lead time in setting up storage system.  By leveraging the on-demand nature, the archival cost is optimized with the use of the lowest cost archive storage as well as the assumption of infrequent access.

What is CDRA Service?

  • A cost-effective and reliable archive storage based on AWS S3 Glacier Deep Archive for archival of infrequent access research data (fastest data retrieval takes about 12 hours)
  • Cost components
    • Size of the data stored
    • Number of items stored (translated to backend storage operations)
    • Network traffic charge, usually in retrieving the data from the archive
    • Number of restore operations
  • The cost varies with the above contributing factors. As a reference, it consumes an annual storage subscription about HK$220 per TB (reference price at July 2022).  Additional cost will be incurred due to data downloaded from the storage and data restore operations.
  • Project Group (PG) leveraging this service will receive one-off credentials with a validity period to perform data archival/retrieval operations
  • Monthly bill of usage will be sent to PG owner

Benefits of CDRA service

  • Agility – there is no need to wait for hardware procurement, installation and configuration
  • A security framework in cloud to ensure data isolation amongst Project Groups
  • Only permit authorized access to the storage from HKU campus network
  • User only needs to bear the direct cost of the service(s) and ITS will absorb the billing and cloud administration overheads
  • Alert will be sent to users for any abnormal spending
  • Helpdesk support

How to use CDRA service?

Any HKU professoriate staff who is a research project Principal Investigator (PI) can apply for this service as a Project Group (PG) unit and may delegate up to 3 staff supporting the file archival/retrieval operations.  Please send an E-mail to to request for the CDRA service.


Upon successful application, the PG unit will be provided with a user guide for data archival/retrieval and assigned credentials to access their storage pool.  The file archival/retrieval operations can be carried out with application clients on both Windows and Linux platforms.


To provide a summary of archived data, ITS strongly recommends PG unit setting up a human readable index file to provide a high-level summary of each archive data set for future reference.  With reference to Libraries’ Research Data Service, the summary (also known as metadata) typically includes information such as ‘who created the data’, ‘what is the data about’, ‘are there any restrictions regarding who can use the data and in what circumstances’.


Users are recommended to refer to RDA Metadata Directory – A list of metadata standards by discipline maintained by the Research Data Alliance Metadata Standards Directory Working Group.

CDRA Take Down Policy

ITS will take down archived data without notice if the funding to support the archive data is discontinued in project group, in its belonging department, in its belonging faculty (if applicable).


ITS accepts no responsibility for mistakes, omissions, or legal infringements within the deposited object. While every effort will be taken to preserve the dataset, ITS is not liable for loss or damage to the data or any other data stored through the CDRA Service (or any repository to which the data is subsequently migrated, as indicated above).

References on Research Data Management


Multi-Factor Authentication

February 2024
February 2024

Mandatory for all staff accounts

May 2024
May 2024

Mandatory for all student accounts