Home directories
    • Your home directory on Discovery is physically on either the ZFS storage system or the Isilon parallel filesystem, and are available from all the compute nodes.
      • Some users that are associated with members that have their own headnode may have their home directories physically on that system.
    • Your disk quota for your home directory is 20 GB.
    • To view your home directory disk usage, use the quota command.
  • Additional disk-space may be leased by members for $50/50Gb for 4 years of use. (1Tb maximum)
Snapshots
    • Snapshots are available of your home directory if your home is in /home, /ihome or /cgl/home.
    • They can be used easily to recover files.
    • For /home and /cgl/home, cd to ~/.zfs/snapshot.
        • In that directory you will find six daily snapshots directories, Monday to Saturday, and Weeklys named Week##, which is taken on Sundays.
      • The dailies are refreshed every week and the weeklies are refreshed every year.
  • For /ihome, cd to ~/.snapshot (this is an invisible directory, but it is there)
    • There will be three types of snapshots in this directory.
        • Daily – each of these is kept for one week and are taken every day.
            • The format of this snapshot is daily-<username>_YYYY-MM-DD
          • There will be a link to the last daily snapshot named daily-<username>
        • Weekly – each of these is kept for one month and are taken on Sundays
            • The format of this snapshot is weekly-<username>_YYYY-MM-DD
          • There will be a link to the last weekly snapshot named weekly-<username>
      • Monthly – each of these is kept for one year and are taken on the 1st of the month.
          • The format of this snapshot is monthly-<username>_YYYY-MM-DD
        • There will be a link to the last monthly snapshot named monthly-<username>
AFS Home
    • If the user has an AFS account, they may have a link to their AFS home directory in their Discovery home directory.
  • You will need to use the klog command prior to getting access to your files in AFS.
Scratch Space
    • Depending on the node, there is anywhere from 175G to 707G in the /scratch partition for local storage.
      • The following table shows the size per cell:
        cell
        size
        cell
        size
        cell
        size
        a 134Gb b 135Gb c 820Gb
        d 820Gb e 820Gb f 849Gb
    • If your program reads or writes large amounts of data, it will run more efficiently if your data is on local scratch space (/scratch).
    • There is central scratch space available if your job needs to read/write common data across all the nodes.
        • This is available in /global/scratch.
      • There is approximately 4TB of space available.
  • Data in these directories are routinely cleaned by the system if they haven’t been accessed for 10 days or more.