The ECN No Name Newsletter is no longer being published. This is an archived issue.

Netscape Cache: A Quota Killer

Stacey L. C. Clark
stacey@ecn.purdue.edu

One piece of software that plagues many users' efforts to manage their disk usage is Netscape.Netscape is a great web browser that opens the treasure of information on the WWW.But be warned that surfing the Web using Netscape, in addition to being addictive, can also sabotage your quota.

What is a quota?

Quota is a means of tracking and limiting disk space usage on ECN general access file servers. Except for certain laboratory disk systems, quotas are used on all ECN home user files systems. Why? Because there IS a limited amount of disk space, and without the quota system, one person could accidentally fill all the disk space of a file system! Then no one else would be able to create or change files on that file system.

What does this have to do with Netscape? Netscape stores a copy of visited web pages on the local disk. Subsequent visits to the page use the local copy, thus, providing enhanced performance. This is called "caching to disk."

By default, Netscape will use up to 5,000K of local disk space for caching. Since, in many schools, students have a quota that is equal to or lower than 5,000K, this can cause problems:

because people don't know that Netscape is caching to disk
because Netscape HIDES the files in a "dot" directory and many UNIX users don't realize that files starting with a dot (.) are treated as special "invisible" files.

Dot Files

Actually, this invisible dot feature is convenient. Files that start with a dot are usually system files, like .login, that you only want to see when working on them. To see files that start with a dot, type ls -a , using the "-a" flag of the ls command. Some typical dot files you might see include:

 .cshrc       .dt         .dtprofile
 .login       .logout     .netscape
 .newsrc

Emptying Netscape Cache

Since I have been using Netscape Version 2 and Netscape Version 3, I have cache files in TWO different directories. (Ack!) .netscape-cache is the cache depository for the older version of Netscape, while the current version of Netscape has a cache in the .netscape/cache directory. Contents of the cache might look like this:

52 cache319386D200B0318.html
12 cache319386F100E0318.gif

Determining Disk Usage

Quota
To determine the quota you have on your account, type quota -v. The verbose flag (-v) is needed, unless you are over quota already.
Disk Usage
For a summary of your disk usage in kilobytes (same as your quota), type du -k" from your HOME directory.
Disk Usage By Netscape
Type du -k .netscape/cache to find out how much of your disk usage is Netscape cache files.

What can you do if you have accumulated tons of files? How can you prevent Netscape from sabotaging you?

Resolving Cache Problem Via Netscape 3

If you are using Netscape 3, you click on Options, and a menu will appear.

Choose Network Preferences, and a dialog box will appear.

You can then set Disk Cache to a small number (100). There is also a box, Clear Disk Cache Now, that lets you wipe out all your old cached files. This is an easy one-button fix!

Resolving Cache Problems Via UNIX

To remove your Netscape cache file from a UNIX prompt, type cd .netscape/cache . Use the ls or the pwd command to verify you are in the correct location.
Type rm * to remove ALL the files stored in this directory.
Another method is typing from your HOME directory
rm -r .netscape/cache .
If you have files remaining from using an older version of Netscape, you can use the above commands but remember to reference the .netscape-cache directory.

BE CAREFUL! This is a powerful command and UNIX will do as instructed. A typo could accidentally result in wiping out everything your own.

Over Quota Blues

If you are already over quota and have hit your hard limit, you are not allowed to write one more bit to disk. Since many Suns & HPs use the Common Desktop Environment (CDE), this can be a problem. CDE starts up a session log file in the .dt directory. If you are trying to figure out what went wrong, this session log is very handy. However, if you are just trying to log onto the computer but cannot because you can't write to .dt/startlog, this is very frustrating! What you can do is log in to a "dumb" terminal or log into a Sun terminal in "dumb terminal" mode. To do this, use the mouse to open the Options menu of the Login screen. Holding down the mouse button, choose the Command Line Login and release the mouse button. The normal login screen should disappear, and a white screen with text should come up. Press return once or twice to get a prompt and then log in as usual.

webmaster@ecn.purdue.edu

Last modified: Thursday, 17-Apr-97 11:29:33 EST

HTML