Home Directories

Each user is provided a home directory to store frequently used items such as source code, binaries, and scripts. Home directories are located in a Network File Service (NFS) that is accessible from all NCCS resources as

/ccs/home/$USER


The environment variable $HOME will always point to your current home directory. It is recommended, where possible, that you use this variable to reference your home directory. In cases in which using $HOME is not feasible, it is recommended that you use /ccs/home/$USER.


Because the NFS servers are outside each NCCS HPC system, NFS does not provide the highest performance.

Each user has a default storage limit of 2 GB in his or her home directory. To request an increased quota, please submit the special request form for review.

In addition to the .yesterday backup described below, home directories in NFS are copied to tape backup four times a week.

To find your quota and usage in NFS, use the quota command or lsquota utility:

> quota -Qs
Disk quotas for user usrid (uid 12345):
     Filesystem  blocks   quota   limit   grace   files   quota   limit   grace
nccsfiler1a.ccs.ornl.gov:/vol/home
                  4858M   5000M   5000M           29379   4295m   4295m
>

where

  • blocks is the current usage and
  • quota is the current quota.

Each home directory has a default set of subdirectories.

private
This directory is accessible only by the user.
.yesterday
This directory contains a read-only copy of the rest of the home directory, including other subdirectories, as of the day before. The copy is generated at 4 a.m. each morning. If you accidentally delete any of your NFS files, you can simply copy versions from the day before out of .yesterday. You cannot directly create or remove files from the .yesterday directory.
www
Documents kept in this directory can be made available over the World Wide Web provided the permissions allow readability. Please contact the UAC to arrange for this directory to be accessible over the web.