On 11/06/12 21:21, Feuerbacher, Alan wrote: > Ok, so mounting IS a lot more than just a way of looking at things. It's > doing something *physically*. That clears up a lot. > >>> Why does one have to create a directory with that name before >>> executing the "mount" command? >> The system has to know where to attach the data structures in the file >> tree. You could create a script to do a 'mkdir -p <mountpoint>; >> mount...', but that's overkill. > Now I'm confused again. I thought that creating a directory actually writes > data into a place on a hard disk that the kernel allocates for the directory. > Something about inodes, if I remember right. But if that's so, and a > filesystem is not yet mounted, where does that data get written? It looks > like the cart is before the horse. > > Specifically, if you want to do "mount /dev/sda5 /mnt/lfs", but you have to > create the directory "/mnt/lfs" BEFORE you do the mount, then where does the > inode information about "/mnt/lfs" get written? I'm sure I'm missing some > details. > In the beginning, you just have the root filesystem.
As any filesystem, it is "just" a map from paths to content. When you create the directory /mnt/lfs, this writes something to the disk. [ as it is a directory it does not touch inodes, but that's besides the point ] So now you have a root filesystem (/) saying that "/mnt/lfs" is a directory, (You could create files in there if you wanted) When you say "mout /dev/whatever /mnt/lfs" it just creates some structure in the kenel, telling he kernel to access some data on your /dev/whatever, when you access /mnt/lfs/foobar. So, after the mount, the kernel has some new data, but neither your root filesystem, nor /dev/whatever has any data written on it. /H -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
