Glossary

Manual pages named by the deck: man rsync, man tar, man sha256sum, and man mksquashfs.

mpiFileUtils manual: https://mpifileutils.readthedocs.io/ (dwalk, dcp, dsync, drm, dtar).

SURF pages, by the topic the deck names:

• Connecting to the system. The SSH host is snellius.surf.nl.
• Data Archive from Snellius. Tools and paths: daget, /archive, partition staging. Login host: archive.surf.nl.
• How to use Rclone with Research Drive. The remote in the example is RD.
• Snellius filesystems. Names from the deck: $TMPDIR, scratch-node.
• An mpiFileUtils easyconfig, for a site that provides no module. The course cluster already has mpiFileUtils installed.

Glossary

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metadata server

Records each create, open, and close. A million small files queue here while the data servers wait.

data server

Moves the bytes of a file.

home

Directory for code and notes.

scratch

Place for the heavy copy.

project

File system for a group’s long-lived data.

node disk

Disk on the compute node. Inside a job it is $TMPDIR. It is removed when the job ends.

partial file

The incomplete file --partial leaves behind so the next rsync continues.

checksum

The sha256sum record of an archive. sha256sum -c prints src.tar: OK when the bytes match.

squashfs

One file, built with mksquashfs -comp zstd, that you can mount read-only.

mpiFileUtils

MPI programs for a large tree: dwalk, dcp, dsync, drm, dtar. EESSI 2023.06 and 2025.06 do not provide them. The course cluster has them installed.

Data Archive

Tape at /archive/$USER on Snellius login and staging nodes. Compute nodes do not mount /archive. The login host is archive.surf.nl.