Starting with RAIDiator 3.01, there is comprehensive memory test that you can run on the ReadyNAS. To invoke it, power-down the ReadyNAS and depress the front power button, until you see all disk LEDs blink together for the 5th time (ignore the quick flash at the beginning). Disks will blink for about a second at about the 5-, 10-, 15-, 20-, and 25-sec mark. Release at that point. The first disk LED will come on to signify the first of an 8-stage memory test. The LED sequence for the 8 stages will be in binary format going from left to right. When all disk LEDs are lit, the memory is good. If the first and second LED blink, followed by the 3rd and 4th LEDs, in alternating pattern, the memory is bad.

Please keep in mind that the success rate for flagging an actual bad memory is about 85%, so we do recommend that you run this test twice.

Sometimes, users are concerned that their ReadyNAS is running out of memory when they review the mem_info.log and see that there is significantly less memory free than should be available.

ReadyNAS is powered by Linux; since it is faster to retrieve data from memory than a hard disk, Linux keeps recent data cached in memory until it needs to replace it.

Problem State:

The easiest way to spot a problem is to check the available swap space. There is information the CPU requires to function that usually lives in memory; if the device is running out of memory, that information gets swapped to the hard disk.

To check this, go to Status > Logs > Download all logs and refer to the mem_info.log.

If there were a real memory problem, the SwapFree would be greatly reduced and the Cached would be at or near zero (0).