|
6 | 6 |
|
7 | 7 | CSCS supports different file systems, whose specifications are summarized in the table below: |
8 | 8 |
|
9 | | -| | `$SCRATCH` | `$PROJECT` | `$STORE` | `$HOME` | `$PROJECT_ID` | `$SCRATCH_ID` | `$STORE_ID` | |
10 | | -|----------|-----------|-----------|----------|--------|--------------|--------------|------------| |
11 | | -| Access Speed | Fast | Fast | Fast | Slow | Fast | Medium | Slow | |
12 | | -| Capacity | 8.8 PB | 91 PB | 1.9 PB | 160 TB | 91 PB | 6.0 PB | 7.6 PB | |
13 | | -| Data Backup | None | None | None | 90 days | 90 days | 90 days | 90 days | |
14 | | -| Expiration | 30 days | 30 days | 30 days | Account closure | End of the project/contract | End of the project | End of the contract | |
15 | | -| Quota | Soft (1M files) | Soft (150 TB and 1M files) | None | 50GB/user and 500k files | 150 TB and 1M files | Maximum 50k files/TB | Maximum 50k files/TB | |
16 | | -| Type | Lustre | Lustre | GPFS | GPFS | Lustre | GPFS | GPFS | |
17 | | - |
18 | | -To check your usage, please type the command `quota` on the front end Ela. |
19 | 9 |
|
20 | 10 | Please build big software projects not fitting `$HOME` on `$PROJECT` instead. |
21 | 11 | Since you should not run jobs from `$HOME` or `$PROJECT`, please copy the executables, libraries and data sets needed to run your simulations to `$SCRATCH` with the Slurm transfer queue. |
22 | 12 |
|
23 | 13 | Users can also write temporary builds on `/dev/shm`, a filesystem using virtual memory rather than a persistent storage device: please note that files older than 24 hours will be deleted automatically. |
24 | 14 |
|
| 15 | +[](){#ref-storage-quota} |
| 16 | +## Quota |
| 17 | + |
| 18 | +You can check your storage quotas with the command quota on the front-end system ela (ela.cscs.ch) and the login nodes of [eiger][ref-cluster-eiger], [daint][ref-cluster-daint], [santis][ref-cluster-santis], and [clariden][ref-cluster-clariden]. |
| 19 | + |
| 20 | +```bash |
| 21 | +$ quota |
| 22 | +Retrieving data ... |
| 23 | + |
| 24 | +User: testuser |
| 25 | +Usage data updated on: 2025-02-21 16:01:27 |
| 26 | ++------------------------------------+--------+-----+-------+----+-------------+----------+-----+---------+------+-------------+ |
| 27 | +| | User quota | Proj quota | | User files | Proj files | | |
| 28 | ++------------------------------------+--------+-----+-------+----+-------------+----------+-----+---------+------+-------------+ |
| 29 | +| Directory | Used | % | Used | % | Quota limit | Used | % | Used | % | Files limit | |
| 30 | ++------------------------------------+--------+-----+-------+----+-------------+----------+-----+---------+------+-------------+ |
| 31 | +| /iopsstor/scratch/cscs/testuser | 4.0K | - | - | - | - | 1 | - | - | - | - | |
| 32 | +| /capstor/scratch/cscs/testuser | 8.0K | 0.0 | - | - | 150.0T | 2 | 0.0 | - | - | 1000000 | |
| 33 | +| /users/testuser | 32.0K | 0.0 | - | - | 50.0G | 42 | 0.0 | - | - | 500000 | |
| 34 | ++------------------------------------+--------+-----+-------+----+-------------+----------+-----+---------+------+-------------+ |
| 35 | +``` |
| 36 | + |
| 37 | +Quotas apply to the total size of stored data, and in some cases to the number of [inodes](https://en.wikipedia.org/wiki/Inode), to the filesystems on Alps. |
| 38 | +The command reports both disk space and the number of files for each filesystem/directory. |
| 39 | + |
| 40 | +??? note "what is an inode" |
| 41 | + inodes are data structures that describe Linux file system objects like files and directories - every file and directory has a corresponding inode. |
| 42 | + |
| 43 | + Large inode counts degrade file system performance in multiple ways. |
| 44 | + For example, Lustre filesystems have separate metadata and data management. |
| 45 | + Excessive inode usage can overwhelm the metadata servces, causing degradation across the filesystem. |
| 46 | + |
| 47 | + !!! tip |
| 48 | + Consider archiving folders with the tar command in order to keep low the number of files owned by users and groups. |
| 49 | + |
| 50 | + !!! tip |
| 51 | + Consider compressing directories full of many small input files as squashfs images - which pack many files into a single file that can be mounted to access the contents efficiently. |
| 52 | + |
| 53 | +!!! note |
| 54 | + The size of the quota depends on the file system, platform and project. |
| 55 | + |
| 56 | +[](){#ref-storage-cleaning} |
| 57 | + |
| 58 | +## Cleaning Policy and Data Retention |
| 59 | + |
| 60 | + |
25 | 61 | ## Scratch |
26 | 62 |
|
27 | 63 | The scratch file system is designed for performance rather than reliability, as a fast workspace for temporary storage. |
|
0 commit comments