I have 4 hard drives on my system. CentOS is in a logical partition on the first hard drive and there is a swap partition in a logical partition on the first hard drive which I have also told it to use. The other three hard drives contain various partitions, all of which I have hidden from CentOS which are primary partitions. I have as well hidden the primary partitions on the first hard drive also. While there are other Linux parttions I do not want CentOS to use them in any way right now. Yet when I restart or shutdown CentOS I get messages saying that there are DMA errors waiting for some hard disk event on another hard dribe before the OS eventually reboots or shuts down my system. I have checked the mount and nothing but the two partitions with which I have set up to run CentOS are mounted. Why then is CentOS trying to access other hard drives upon shutdown ? Is there some way that I can curtail the OS from doing so ?