Quota Help


Some students are having problems with quota that result in them losing their files. To prevent this problem:

1. make backup

Perform #1 at regular intervals when you have a version of your assignment that you want to save. You can then easily retrieve another copy of your files in case files are deleted by mistake. This method is your best defense. Many students do not do this, and when your file is lost, the only choice you have it to start over again.

2. make clean

Perform #2 in all old directories. This will remove "core" files, executables, and object files in old homework directories. You are asking for trouble if you don't "make clean" when you are done with an assignment. All your source code is still retained.

3. quota -v

Please be familiar with your quota and know when you have too many files.

4. rm core

Please remove core files when you are done with them. You can use the debugger to look at a core file to see what's wrong with your code...

gdb Driver core

After you are done, remove the core! Alternatively, "make clean" will also remove the core.

5. du

from your home directory. "du" is the Disk Usage command. It can help you to identify which directories have the most usage. You can then go to those directories and clean up. Some of you have too big of a Netscape cache. Others of you do not empty your Trash from the desktop. Both of these can be quota hogs.

6. rm -r backup

After you have received your score for an assignment, you don't need your backup directories anymore. Please remove them when you are done. You'd execute the above command from any of your homework directories. Don't execute the command UNTIL YOU GET YOUR SCORE FOR THAT ASSIGNMENT.

7. gzip *

Also, after you have received your score for an assignment, you should compress your source files to save disk space. The above command should be executed in any homework directory. To restore your files to their original state, the command is:

gunzip *.gz


The main problem happens when you are out of quota (due to a core most of the time) when you are editting a file. When you write the file out to disk, you are actually first removing the old file, and then you replace the removed file with a fresh copy. You always have enough quota to remove the old file, but you may not have enough quota to replace the file with an updated copy. The result is that YOUR OLD FILE IS REPLACED ON DISK WITH AN EMPTY FILE, and YOUR WORK IS GONE!!! The ACS can assist in file recovery, but there are no guarentees, and the recovery often takes a few days...too long when your program is due the next day.

You should be aware of any message like "write failed" that appears when saving a file. If this happens to you, DO NOT LEAVE THE EDITOR. Open another window, "make clean" to get more quota, do other clean up of unwanted files, "quota -v" to see that you have enough space, then you can return to the editor where your file is still in memory to successfully save your work.

Unfortunately, this problem has happened too many times, and it's always a sad experience when it happens to you. Please take this advice VERY SERIOUSLY! The best defense is for you to be aware and to have a backup copy of your files in your own account.