The Quasar archive is a cold, tape-based archive for storing curated data collections that have an indefinite lifetime. It is not designed to serve data or to store data that will be frequently accessed, overwritten, or deleted. (Active data should be on GLADE or Campaign Storage rather than on Quasar.)
Before requesting access, please review the following information regarding how to archive files, the minimum and maximum file sizes, and related use policies.
Users store data on Quasar by transferring files via the Globus endpoint named NCAR Quasar. For documentation about how to use Globus, see Globus file transfers.
A note about verifying Globus transfers
Using the Globus checksum sync option when transferring files can result in "operation timed out" error messages when it causes file recalls from tape, which can be slow.
To avoid such errors when doing an incremental backup, use a different sync level – exists, mtime or size, for example – when making the transfer.
To verify that a just-completed transfer did not encounter any corruption, do the checksum immediately to complete it before files are transferred to tape and purged from the disk cache.
The following requirements apply to files stored in a project's high-level allocation (RDA or EOL, for example).
The system is designed to support large file writes effectively. As a tape-based archive, however, it is not designed to support frequent read activity. File reads should be infrequent, and data and metadata changes should also be rare.
Under normal operational use, no more than 10% of your files should be read, rewritten, renamed, or deleted during any 12-month period. If a special case arises – a recovery operation, for example – and you anticipate more activity, please contact the NCAR Research Computing help desk.
Disaster recovery storage is available to approved projects. When a disaster recovery account is approved, a secondary directory tree is made available for users’ data
The data are written to a separate pool of tapes from the primary data copies. The disaster recovery tapes are moved from the TS4500 library as they fill up and are stored in a fireproof vault in Cheyenne, Wyoming. See Quasar system specifications for details.