Optimizations

This page gives some hints and optimizations you can make to tune your MINIX 3 system to match your requirements.

Use the RAM Disk

MINIX 3 supports a RAM disk, which allows you to put a portion of your file system in memory instead of on the hard disk. When booting the system, the RAM disk is read in from subpartition a of your MINIX 3 partition, for example, from /dev/c0d0p2s0. If you have a large amount of memory, say > 512 MB, you might wish to use the RAM disk. The advantages are:

• Better performance when accessing files on the RAM disk

The disadvantages are:

• Booting the system is slower since the RAM disk has to be read in
• Shutdown is slower since modified RAM disk files have to be rewritten to the hard disk
• Some memory is wasted

To use the RAM disk, boot MINIX 3 and enter the boot monitor by hitting ESC. Then type:

Increase the File System Buffer Cache

If you have a large memory, you may also wish to increase the size of the file system buffer cache. To do this, change the value of the constant NR_BUFS in include/minix/config.h. This value tells how big the cache is in disk blocks (normally 4 KB), so a value of, say, 4096, creates a 16-MB cache. Then rebuild and reboot the system.