Quotas Defined

Quota limits are necessary to ensure that disk space can be made available to all users and that work is not impeded by full file systems. Users get default quotas on various file systems at LC. This is the amount of space and number of inodes that can be put on the specific file system by the user. Once the user hits their quota, they won't be able to write any more data until they remove some data.  

Quotas for File Systems

The table below shows how much quota (Tier 1, Tier 2, Tier 3) is available on various file systems. By default, you get Tier 1.  

If you need more quota than the default, you can request Tier 2 via this form on specific file systems. 

If you need more than Tier 2, you can request Tier 3 via an email to lc-hotline@llnl.gov Remember that Tier 2 and Tier 3 are file system AND Zone specific. This means that if you request Tier 2 to get that bump to 75TB/25M on /p/lustre1 on the CZ, that is the only place you get it. If you need Tier 2 on /p/lustre2 on the CZ, that is a second request. Please make each request separately so that it can be directed to the appropriate authorizer. 

To see how much quota you have used

• Log onto a slic machine (CZ - oslic, RZ - rzslic, SCF - cslic)
• type "quota -v"
  • shows your space utilization of various file systems mounted in that particular zone (CZ/RZ/SCF)
  • shows your inode utilization of various file systems as well
• for directories like /usr/workspace or /usr/gapps you can see your space utilization like this
  • df -h /usr/workspace/$user   ## for the space utilization of the directory
  • df -h /usr/gapps/<directory>  ## for the space utilization of directory
  • df -hi /usr/workspace/$user   ## for the inode utilization of the directory
  • df -hi /usr/gapps/<directory>  ## for the space utilization of directory

NOTE: An inode is a magical linux construct that makes life so much easier.  Basically, each file/directory/symlink is assigned a unique number.  There is a limit to the number of inodes that can exist on any given file system and in a given directory. Here is a link that has more detail http://www.grymoire.com/Unix/Inodes.html

Quotas for Storage

Storage (HPSS)  is LC's hybrid (disk/tape) archive system where users can store data for later.  For more info on the tape archive - go to https://hpc.llnl.gov/documentation/user-guides/using-lc-archival-storage .

To see how much quota you have used, 

• Log onto a slic machine (CZ - oslic, RZ - rzslic, SCF - cslic)
• type "kinit"
  • you will be prompted for your username and password - that is your RSA or RZ token and pin
  • gives you the required kerberos credentials
• type "aquota"
  • your prompt will change to "aq>"
  • puts you in the command line storage quota tool application
• type "show quota"
  • tells you how much quota you currently have
• type "exit" 
  • returns you back to your normal prompt 

Quota Warnings

PLEASE ATTEND TO WARNING MESSAGES!

You risk losing data if you exceed your quota. Output to a home directory that is over quota will be truncated. Files moved to such a directory will also be truncated. Just opening a file for editing while you are over quota can cause the loss of the entire file's contents. Unfortunately, these are results of the UNIX implementation of quota and can be prevented only by user attention to quota warnings.

Carefully consider before you execute a batch job that attempts to write to your home directory space. If you exceed disk space quota:

• You will get truncated or zero length files and waste the run because the output is lost as a result.
• You will lose further data if your home directory remains filled after the job finishes, if you attempt to copy, write or edit files.
• MULTIPLE ATTEMPTS TO WRITE TO A DIRECTORY THAT IS OVER QUOTA WILL CREATE A SIGNIFICANT BURDEN ON THE NFS SERVER, CAUSING INTERACTIVE DELAY AND PERFORMANCE PROBLEMS. In some cases, jobs create hundreds of thousands of write attempts, quota checks, and refusals to write within a few minutes.

Quotas for File Systems and Storage