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Description of problem: dm_mod is loaded in SL6.1, but i no use RAID or LVM. The script /etc/rc.d/rc.sysinit contain: # Device mapper & related initialization if ! __fgrep "device-mapper" /proc/devices >/dev/null 2>&1 ; then modprobe dm-mod >/dev/null 2>&1 fi And, my /proc/devices contain 253 device mapper device, but, i no use RAID or LVM, so, is a kernel or device-mapper bug? Version-Release number of selected component (if applicable): SL6.1, kernel 2.6.32-220.4.1.el6.i686 How reproducible: Always Steps to Reproduce: 1. 2. 3. Actual results: The kernel module dm-mod.ko is loaded by default, but the system not use RAID or LVM Expected results: No load dm_mod Additional info:
No it is not a bug. Some kernel modules all loaded to ensure that storage stack always contains this functionality - if you plug in disk with e.g. LUKS (encrypted flash) or LVM it can be then handled properly. And several RHEL system scripts require dm-ioctl functionality (mkinitrd for kernel upgrade for example). If you have some "hardened" or tuned installation, you can rmmod that later of course but you can expect some warning later. In /proc/devices is just registered device type, not a real mapped device (for real mapped device see "dmsetup table" - it should be empty in your case.
*** Bug 789639 has been marked as a duplicate of this bug. ***
As Milan says, if you know for certain you won't need it later in the life of the system and it bothers you, just 'rmmod' the module at the end of initialisation.