what do the numbers after the : /dev/block/vold/179:xx mean? I've been trying to figure out an micro sd card issue and just stumbled upon a page where someone mentioned that the numbers after the colon would represent xyz and if they are something different then they will represent abc.  I'm having issues with cm12.1 recognizing my micro-sd card and I've been trying to fix it with fsck in terminal.  When I manage to find where it's mounted the numbers I am seeing are 179:33...anyone know?  Thanks.
These are the "major device number":"minor device number" (You can list them with cat /proc/partitions in adb). The major device number selects which device driver is being called to perform the input/output operation. This call is being done with the minor number as a parameter and it is entirely up to the driver how the minor number is being interpreted. The driver documentation usually describes how the driver uses minor numbers.

The sc-card is normally mounted by the volume daemon (vold). The output of mount shows you where the according mount points are.