FAQ - System Performance

Why does my system use so much memory?

From the Linux Journal -- "When extra physical memory is not in use, the kernel attempts to put it to work as a disk buffer cache. The disk buffer stores recently accessed disk data in memory; if the same data is needed again it can be quickly retrieved from the cache, improving performance. The buffer grows and shrinks dynamically to use the memory available, although priority is given to using the memory for paging. Thus, all the memory you have is put to good use. "

What can I do to fix a kernel panic?

The vast majority of kernel panics are caused by hardware issues. A small minority of panics are caused by hardware driver issues. The Linux operating system will chug along doing its work, but when it bumps into a fatal hardware problem, it will stop right away (panic). The most common causes:

• Incompatibilities with custom built machines (as opposed to prebuilt systems from Dell, HP, etc.)
• Overheating
• Mismatched system memory / RAM
• Hard disk or controller failure
• Loose cables or cards

In an effort to avoid any damage (for example, file system damage), most kernel panics are not logged. For example, if the Linux kernel detects bad memory, there is no way for it to trust that it has the right information to write to the hard disk. If you need help diagnosing a kernel panic, right down the information (cryptic as it may seem) or take a picture.

Why is my system slow?

Check DNS

Many software packages (webmail, web server, mail) will do a reverse DNS lookup when a remote system connects to ClarkConnect. This reverse DNS lookup is helpful for diagnosing issues in log files. For instance a log file that shows the DNS name mail3.blackberry.net instead of an IP address (for example, 12.43.32.12) is easier to analyze. However, if the reverse DNS system is slow or not functioning, your ClarkConnect system will appear to be running slow.

Misbehaving software

Software is not 100 percent perfect. From time to time, software can degrade the performance of a system. A reboot can sometimes clear up a problem. If the problem persists, then further investigation is required.