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Contents


Dell Linux clusters

Home Directory

For all LONI Linux clusters, the /home quota is 5 GB. Files can be stored on /home permanently, which make it an ideal place for your source code and executables. In the meanwhile, it is not a good idea to use /home for batch job I/O.

Work (Sratch) Directory

For all LONI 5TF Linux clusters, the quota on /work (/scratch) is 100GB. Please note that the scratch space should only be used to store output files during job execution, and by no means for long term storage. Emergency purge without advanced notice may be executed when the usage of disk approaches its full capacity.

For Queen Bee, no quota is enforced on /work but we do enforce a 30 days purging policy, which means that any files that have not been accessed for the last 30 days will be permanently deleted.

Checking One's Quota

Issuing the following command,

$ showquota

results in output similar to:

Disk quotas for user lyan1 (uid 24106): 
    Filesystem    MB used       quota
    /home             105        5000
    /work             606      100000

IBM p575 clusters

Home Directory

Mount point: /home/username

Users have a quota of 500MB for their home directory. If a user exceeds this limit he will begin receiving error messages when he tries to use more disk space. Once he exceed 550MB all operations that would result in allocating more disk space in his home directory will fail.

Local Scratch

Mount point: /scratch

Every cluster has local scratch space on each node that may be used to temporarily store files during the execution of a job. The amount of space within the /scratch filesystem varies from node to node (depending on the total amount of disk space available).

Note: After writing to /scratch, files you write there will be deleted after your job completes.

Work Directory

Mount point: /work/default/username

Individual users have a quota of 20GB total within this filesystem.

Temporary Overflow Work Space - Bluedawg Only

In response to the lack of space in the NFS filesystem mounted at /work/nfs101/ on Bluedawg, additional disk has been made available on that cluster. You can access this disk via the path /work/nfs102/ or using the canonical name /mnt/lpfs.nfs102/.

This disk is larger than that offered by the original work disk and the per-user quota has been increased to reflect this. Users can now write up to 50GB of data to this disk, compared to the 20GB available on the original filesystem.

As with the other work filesystem, the given quotas represent an overcommittment of the disk. This decision allows jobs generating large datasets to run on this hardware. However, given this fact, please treat this filesystem as a temporary resource meant to store data for the running of jobs only. Your fellow users will appreciate it. This request also pertains to all other LONI cluster filesystems.


Checking One's Quota

Issuing the following command,

# quota -v

results in output similar to:

Filesystem          blocks      quota    limit    grace    files      quota    limit    grace
/mnt/home           77832      500000   550000              1111       5000     5500         
/mnt/work.nfs101    75884    20000000 20500000               222     900000  1000000

This will tell one how close he is to the limit.

Notes on Number of Files in a Directory

All users should limit the number of files that they store in a single directory to < 1000. Large numbers of files stored within a single directory can severly degrade performance, negatively impacting the experience of all individuals using that filesystem.


Users may direct questions to sys-help@loni.org.

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