The National Institute for Computational Sciences

File Systems - SIP

Summary

The below table describes the ACF file systems.
File System PurposePath to User's DirectoryQuota, Purge policyEncrypted
Home Directory /nics/[a,b,c,d]/home/{username} 10GB quota, not purged No
Lustre Scratch Directory /lustre/sip/proj/{project}/{username} No Quota , purged No
Project Directory /projects/{project} By Request, not purgedYes
ACF file systems are generally very reliable, however, data may still be lost or corrupted. Users are responsible for backing up critical data unless arrangements are made in advance. Backups can be provided by request for a fee for critical data.

Backups are performed on the Home Directory file system. Lustre SIP project directories are only backed up by request for a fee. Lustre SIP scratch directories are NOT backed up.

NFS Home Directories

NFS space is available and used for home directories with approximately 500 gigabytes (GB) of space available in this file system. User home directories are provided by NFS and is unpurged with a default quota of 1 gigabytes (GB) of storage space. This is the location to store user files up to the quota limit. The environment variable $HOME points to your home directory path. To request an increase in home directory quota limit submit a request to help@nics.utk.edu.

Home directories are regularly backed up.

SIP Project space

Encrypted project space is available on each login node for each project. The location of each project's project space is at the /project/{project-name} location. As part of the project creation process the PI will be contacted to create a password for this encrypted project space. The current process is there is one password for this project space known to all project users. However, up to 7 additional passwords can be created if there is a need to do so. Each user should create their own subdirectory under this project space the first time one makes use of the project space. There is a special process to mount this project space on the UTK or UTHSC login node. Each project will get a password that allows users to mount and use this space. Use the following command to mount your project space:
sudo luksmount {project-name}

For example:
[victor@sip-login1 ~]$ sudo /usr/local/bin/luksmount SIP-STA0001
Enter PASSCODE: (this is your SIP account two factor authentication)
Enter passphrase for /dev/VolGroup/lv_SIP-STA0001: (this is the encrypted project directory space password authentication)

Once the above commands are completed then the project directory will be mounted. Also, once someone is finish working with this project data (termed "data at rest") the project space should be unmounted to keep it protected.

[victor@sip-login1 ~]$ sudo /usr/local/bin/luksunmount SIP-STA0001
Enter PASSCODE:

No addt'l password is needed to unmount the file system.

Scratch Directories on Lustre SIP

The Lustre SIP file system provides about 15 terabytes (TB) of global high performance scratch space for data sets related to running jobs on the SIP resources and transferring data in and out of the data transfer nodes. Every user has their own scratch directory created at account creation time located in their lustre project space /lustre/sip/proj/{project}/{username}.The environment variable $SCRATCHDIR points to each users scratch directory location. Scratch space on SIP can be purged weekly, but has no storage space or quota limit associated with it. Scratch space on the SIP is for storage of data in use and is not required to be encrypted as described in the ACF SIP Security Plan Data that is at rest (not being used) is required to be encrypted in the project space.

Lustre SIP Scratch directories are NOT backed up.

Important Points for Users Using Lustre SIP Scratch

  • The Lustre SIP Scratch file system is scratch space, intended for work related to job setup, running jobs, and job cleanup and post-processing on SIP resources and not for long term data storage. Files in scratch directories are not backed up and data that has not been used for 30 days is subject to being purged. It is the user's responsibility to back up all important data to another storage resource.

    The Lustre find command can be used to determine files that are eligible to purge:

    > lfs find /lustre/sip/{project}/$USER -mtime +30 -type f
    
  • This will recursively list all regular files in your Lustre scratch area that are in eligible to be purged.

  • Striping is an important concept with Lustre—. Striping is the ability to break files into chunks and spread them across multiple storage targets (called OSTs). The striping defaults set up for NICS resources are usually sufficient but may need to be altered in certain use cases, like when dealing with very large files. Please see our Lustre Striping Guide for details.

  • Beware of using normal Linux commands for inspecting and managing your files and directories in Lustre scratch space. Using ls -l can cause undue load and may hang because it necessitates access to all OSTs holding your files. Make sure that your ls is not aliased to ls -l.

  • Use lfs quota to see your total usage on the Lustre system. You must specify your username and the Lustre path with this command, for example:

    > lfs quota -u <username> /lustre/haven
    

For more detailed information regarding Lustre usage, see the following pages:

NICS will be developing additional storage policies and will notify users about any storage policy changes .