Running Unix Memory Test 0.2

The goal of RUMT is to check the memory of a computer over a long period of time and almost-real load conditions without having to interrupt the services.

RUMT exploits the possibility of some Unix kernels to selectivly disable some memory areas while still accessing them through the /dev/mem device. The principle of RUMT is to write pseudo-random data in these disabled memory areas, and later check them. This principle and the original code for the deterministic pseudo-random generator are from David Madore.

This distribution contains another variant on the same theme: URUMT allocates a large chunk of memory, locks it in memory using the mlock(2) system call, and scans /dev/mem to find where in physical memory the allocated area is. Then it continuously runs the same tests in that memory.

URUMT can not be used to test a particular area of memory: the kernel will give it whatever physical memory it feels like. But URUMT can be restarted now and then, hopefully getting different physical memory each time.

This is perfect if you suspect you have bad bits, but do not know at all where they are. Once you have sighted the bad bits, you can use a plain RUMT to test more extensively the neighborhood.