ARCHIVE/PERM

The magnetic tape archive provides additional storage for inactive data for short-term archival and to free up space in the Project, HOME, and SCRATCH/WORK data stores. It is only accessible from the login nodes. Its capacity grows as more tapes are added. Its characteristics are

• Secure file system location on magnetic tapes
• Extremly high latency per IO operation, especially for reading data not in the HDD cache (minutes to open a file)
• Optimized for a small number of large files
• Short-term archival
• Has a quota

For reasons of efficiency and performance, small files and/or complex directory structures should not be transferred to the archive directly. Please aggregate your data into compressed tarballs or other archive containers with a maximum size of 5.5 TiB before copying your data to the archive. For large data, a good target size is 1-2 TiB per file because such files will usually not be split across more than one tape.

The project ARCHIVE/PERM data stores for each kind of project are given in the table below. The directory’s symlink in the Project Map directory for each project has the name dir.perm.

The user ARCHIVE/PERM data stores for each kind of user are given in the table below.