On Tue, 9 Mar 2010 09:43:48 -0500 (EST) "Ken D'Ambrosio" <ken@xxxxxxxx> wrote: > On Fri, March 5, 2010 3:37 pm, Neil Brown wrote: > > mount /dev/md0 /somewhere > > > > ?? > > Sorry this took so long; I've been busy dying from Martian Death Flu. > So... I tried what you suggested. > > And it worked. > > WTF?! > > How can you mount something that doesn't show a partition in fdisk? I'm > -very-, -very- confused here. Grateful, yes, but confused. Is this > something I'm just not "getting?" Yes, this something you are just "not getting", but it is very simple so won't take a moment to explain. A partition table is simply a description of how to divide a disk drive up into smaller units. In stead of 1 big device, you appear to have several small devices. You can create a filesystem on any of these things - the big device, or any of the smaller devices. You can use fdisk to divide /dev/sda up into /dev/sda1, /dev/sda2, etc, but you don't have to. You can "mkfs /dev/sda" if you like. Similarly, you can devide /dev/md0 up into /dev/md0p1, /dev/md0p2, with fdisk, but you don't have to. Commonly, people use /dev/sda1 rather than /dev/sda, and /dev/md0 rather than /dev/md0p1. But this is just common practice, not enforced (that it wasn't long ago when /dev/md0p1 could not be created, but that isn't important here). A partition table does add one byte of extra information - a partition type. This is a hint as to what sort of thing is stored in the partition. However that hint is not widely used in Linux. I think some installers use it to automagically find 'swap' and maybe 'root', but that is about it. For many purposes the partition type can be ignored. When you created your filesystem, you must have created it on /dev/md0, not on a partition. Hope it is all clear now. NeilBrown > > Thanks much, regardless, for the pointer -- don't know if I would ever > have tried mounting it without a partition showing. > > *confused but happy* > > -Ken > > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
