Storage
The KTA Computer System provides several storage options suited to different use cases — from fast scratch space for running analyses to backed-up home directories for final results. Understanding the differences between them is important to avoid data loss.
Overview¶
| Mount point | Server | Total size | Backed up | Quota | Purpose |
|---|---|---|---|---|---|
/home/ktas/<lrz-id> | tuphzit-na3-nfs (NETAPP) | 1.9 T | ✓ Yes | 30 GB/user | Final results, scripts, configs |
/scratch3–11 | rhydon, graveler, golem, etc. | 28–73 T | ✗ No | None | Active analysis, temporary data |
/tank1/scratch | kabutops (ZFS) | 30 T | ✗ No | 30 TB | Active analysis, temporary data |
/tank2/scratch | omastar (ZFS) | 30 T | ✗ No | 30 TB | Active analysis, temporary data |
/tank1/<lrz-id> | kabutops (ZFS) | varies | ✗ No | on request | Personal long-term datasets |
/tank2/<lrz-id> | omastar (ZFS) | varies | ✗ No | on request | Personal long-term datasets |
/local | local disk (per machine) | varies | ✗ No | None | Node-local temporary storage |
Home Directory¶
Each user has a personal home directory at /home/ktas/<lrz-id> (also available as $HOME). Home directories reside on a dedicated NETAPP storage server and are the only storage on the KTA system that is regularly backed up.
Key properties:
Quota: 30 GB per user
Backed up: yes
Available on: all terminal servers and desktop machines
Because home directories are mounted on the desktop machines as well, any files you edit on the desktop are immediately accessible on the terminal servers and vice versa — no manual copying needed.
Scratch Storage (scratch3–scratch11)¶
The scratch volumes /scratch3 through /scratch11 are NFS-mounted from several dedicated storage servers. They provide large, fast storage for running analyses and storing intermediate data.
Any user can create their own directory on a scratch volume:
mkdir /scratch8/$USERThe available scratch volumes and their host servers are:
| Mount point | Server | Size |
|---|---|---|
/scratch3 | rhydon | 37 T |
/scratch4 | rhydon | 37 T |
/scratch5 | graveler | 73 T |
/scratch6 | graveler | 73 T |
/scratch7 | rhyhorn | 73 T |
/scratch8 | rhyhorn | 73 T |
/scratch9 | geodude | 28 T |
/scratch10 | golem | 55 T |
/scratch11 | golem | 55 T |
Tank Storage (ZFS)¶
tank1 and tank2 are newer storage servers that expose their capacity via ZFS, a modern filesystem with better data integrity guarantees than the scratch servers. Tank storage is available in two forms:
Shared scratch directories¶
/tank1/scratch and /tank2/scratch work analogously to the scratch volumes described above. Any user can create a personal subdirectory:
mkdir /tank1/scratch/$USERThe total capacity of each scratch pool is 30 TB, shared across all users. Both directories are cleaned up by the admins from time to time, when space runs low. Do not use these directories for long-term storage.
Personal ZFS datasets¶
For users who need more persistent storage that survives regular cleanups, a dedicated ZFS dataset can be created on tank1 or tank2 upon request. These appear as personal mount points such as /tank1/<lrz-id> and can be allocated a custom quota.
To request a personal dataset, contact kta
Local Storage (/local)¶
Each machine in the KTA system has a /local directory that points to the node’s own local disk. This storage is accessible to all users on that machine and is useful for data that benefits from low-latency local I/O — for example, staging large input files before processing.
mkdir /local/$USERBecause /local is physically attached to a single machine, it is not accessible from other nodes. It is also not backed up and can be wiped without notice. Use it only for truly temporary data tied to a specific running job or session.