File Systems, Purging & Quotas


  1. What is the purge policy for the temporary/scratch file systems?

    The purge policy is based on the file/directory modification time (mod time). This means if you are actively writing to a file, the mod time will be updated for that file

    LocationSymlinkQuotaTime limit
    /mnt/lustre/koa/scratch/koa_scratch800 TB90 days

    The 800 TB quota is shared across all users. 

  2. How do I know how much space I am using on the different storage locations I have access to?

    As users connect to the login nodes, a message of the day is presented, which includes a breakdown of your individual usage for each storage location you currently have access.  This list is currently generated based on the symlinks in the top level of your home directory.   Users may also manually trigger the command named "usage" which will print out the same table as shown in the message of the day.

  3. Why are my files being deleted from the scratch file system soon after I extract them from an archive (tar, tgz, zip, 7z, etc.)?

    Most likely your archive is preserving mod times that are older than the purge policy allows. In order to work around this, you would need to direct your decompression application to not preserve mod times. Below are two common applications and the flag you would use to tell it not to preserve the mod time.

    tar -m
    unzip -D