// Using Mass Storage
NOTICE: The NCCS is not providing new tape storage to users, and read access on MSS has been disabled except for select projects. Please see the Moving Data from Dirac page for information on recalling files and outbound transfers.
Dirac is the system that front-ends the Mass Storage System (MSS). It is recommended that users log into a Dirac node to manage file migration from MSS.
The Dirac nodes mount /archive (the cache filesystems) by CXFS using a fast Fiber Channel connection. CXFS is a proprietary distributed file system similar to GPFS. The limiting factor here is the disk and the bus speeds of the nodes themselves. From the point of view of the Dirac nodes, /archive is a local mount.
// Applications of Dirac
// Key Commands
| Command | Application |
|---|---|
| quota | Queries your individual $HOME quota, but does not account for data on tape. |
| dmdu | Gives an estimate of how much space is used in the current working directory by all files, those on disk and offline on tape. |
| /local/nccs/bin/mssuserreport | Outputs all of your /archive data holdings, including tape. |
| /local/nccs/bin/mssgroupreport | Outputs all of your group(s) data holdings, including tape. |
