Emerald Notes

Emerald: emerald.unc.edu

Getting a UserID

To subscribe to any services, you need an ITS userID (ONYEN); an ONYEN includes a password, disk space, Internet access, and an ITS e-mail address at email.unc.edu. If you do not already have an ONYEN, choose Create/manage ONYEN from the ONYEN webpage to create one. As part of the userID creation process you will subscribe to services. Choose Emerald Linux Cluster to obtain access to Emerald.

If you already have an ONYEN, you can gain access to Emerald by choosing Create/manage ONYEN from the ONYEN webpage. Once there choose Subscribe to Services, and then select Emerald Linux Cluster.

It will take a anywhere from a few minutes to a day or so before a new user will have access.

AFS space

All users have at least 100 megs of space in their AFS home directory:
```
/afs/isis/home/u/s/username/
```
SAS programs can be submitted in this directory and small data sets can be stored there.
CPC projects have more AFS space located in:
```
/afs/isis/depts/cpc/projects/
```
Files here are never "migged out" or "sent to storage." They are backed up on tape and are always available for use.
Yesterday's copies of files are available in the Oldfiles directory:
```
/afs/isis/depts/cpc/projects/usda/Oldfiles/
```
SAS or Stata programs can call upon any dataset in scratch space (not in AFS space) on Emerald no matter where the file is located as long as the user has rights to read that file in that directory.
AFS directory permissions are not Standard UNIX rights. They are known as ACL's (Access Control Lists) and apply to directories and not to specific files. To learn more about them check out: Introduction to AFS.
All users have all rights in their home directories.

MS space (Mass Storage onto tape)

In your home directory you have an "ms" subdirectory:
```
/afs/isis/home/u/s/username/ms
```
When you cd to it you are sent to MS space:
```
/ms/home/u/s/username/work/
```
Your personal mass storage space is not a good place to work on project work because it will be one of the last places anyone would look for it.
CPC has space in:
```
/ms/depts/cpc/projects/
```
Consider this our "attic."
Standard UNIX rights apply in MS.
SAS programs should not be submitted in MS.
This is the suggested space to store datasets that will not be used much.
Technically, we have unlimited amount of space in Mass Storage. It is always wise to save space.
The NE editor can not access files that are on tape. Use the "file" command:
```
file filename
```
to get the file off of tape before trying to edit the file with this editor.

Scratch space

Users can create additional, temporary work space for a short period of time (days maybe weeks), by making a directory in Scratch space:
```
/netscr/username
```
Files in these directories are subject to be deleted at any time.
This is not AFS space so normal Linux/UNIX file and directory permissions apply.
Files here will not be backed up onto tape. If they are deleted they are gone.

How to use Emerald

Use your ONYEN and ONYEN password to access Emerald.

The USDA data are located in:

/afs/isis/depts/cpc/projects/usda/

You have an alias named 'usda' that will bring you to the usda space if you enter 'usda' at the prompt and hit enter. Your screen should look like this:

$ usda

$ pwd
/afs/isis/depts/cpc/projects/usda

Programs should be submitted in batch using the LSF commands: bsub, bsas, or bstata. If you want to submit a program in batch, type:

bsas progname.sas

bstata dofile.do

If you want to gzip a file, type:

bsub gzip filename.sas7bdat

An e-mail will be sent to you telling you whether or not it ran without error. Since there may be a lag between the time the job finishes and the e-mail arrives, you can check on your job by typing bjobs to see if it's still running. After a job is submitted, you can log out while the program is running and your program will continue to run normally.

If you want to run interactive SAS, type:

xsas

If you want to run interactive Stata, type:

xstata