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
ARCHIVE/PERM are SHORT-TERM archives, NOT long-term archives. Thus,
- It is not a solution for long-term data archiving.
- There is no guarantee for 10 years according to rules for good scientific practice.
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 user directories at the present time are at /perm/USER
and the project directories are at /perm/projects/PROJECT
.
PERM will be moved soon and will then have a different path.
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
.
Kind of Project | Path | Media | Capacity | Filesystem |
---|---|---|---|---|
NHR | /perm/projects/PROJECT | tape with HDD cache | growable PiBs | Stornext exported via NFS |
The user ARCHIVE/PERM data stores for each kind of user are given in the table below.
Kind of User | Path | Media | Capacity | Filesystem |
---|---|---|---|---|
SCC | /usr/users/a/USER | tape with HDD cache | growable PiBs | Stornext exported via NFS |
NHR (legacy only) | /perm/USER | tape with HDD cache | growable PiBs | Stornext exported via NFS |