To begin interacting with the disk, we need to mount the file system to the directory. You might be thinking, why can't we just cd into /dev/sdb? That's the disk device, isn't it? It is, but if we try to cd into /dev/sdb like this We'd get an error saying the device is not a directory, which is true. To resolve this, we need to create a directory on our computer and then mount the file system of our USB drive to this directory. Let's pull up where our partition is with sudo parted -l. Okay, I can see that partition that we want to access is /dev/sdb1. I've created a directory already under root called my_usb. So let's give this a try. So sudo mount /dev/sdb1 /my_usb/. Now if we go to my_usb, we can start reading and writing to the new file system. We actually don't need to explicitly mount a file system using the mount command. Most operating systems actually do this for us automatically, when we plug in a device like a USB drive. File systems have to be mounted one way or the other, because we need to tell the OS how to interact with the device. We can also unmount the file system in a similar way using the umount command. Unmounting is the opposite of mounting a disk. So now let's unmount the file system. I can either use sudo umount /my_usb, or sudo umount /dev/sdb1. Both will work to unmount a file system. When you shut down your computer, disks that were mounted manually are automatically unmounted. In some cases, like if we were using a USB drive, we just want to unmount the file system for the USB drive without shutting down. Always be sure to unmount a file system of a drive before physically disconnecting the drive. In the case of the USB drive, we can run into some interesting file system errors if we don't do this. We'll talk more about this in the upcoming lesson. Also, keep in mind that we when we use the mount command to mount a file system to a directory, once we shut off the computer, the mount point disappears. We can permanently mount a disk though if we needed to automatically load up when the computer boots. To do this, we need to modify a file called /etc/fstab. If we open this up now, you'll see a list of unique device IDs, their mount points, what type of file system they are, plus a little more information. If we want to automatically mount file systems when the computer boots, just add an entry similar to what's listed here. Let's go ahead and do that really quickly. The first field that we need to add for /etc/fstab is the UUID or universally Unique ID of our USB Drive. To get the UUID of our devices we can use this command, sudo blkid. This will show us the UUID for block device IDs, aka storage device IDs, and that's it. We've covered a lot of essential disk management tasks. So far we've partitioned a disk, added a file system, and mounted it for use. If you're curious and want to learn more about the /etc/fstab file and its options, check out the next supplemental reading. Otherwise, let's move on
