How to check the formatted disk?

Great question! After formatting the disk, you won't immediately see a change in lsblk that explicitly says "formatted". Formatting itself doesn't make the disk visible in your file system yet; it just prepares it.

To truly "check" if the disk is formatted and ready for use, the next logical step is to mount it. Once it's mounted, you'll be able to access it like any other directory in your file system, and lsblk will show its mount point.

The typical steps to verify and use a newly formatted disk are:

Create a mount point (a directory) where you want to access the disk.
```
sudo mkdir /mnt/newdisk
```
(You can choose any path you like, /mnt/newdisk is a common convention for temporary mounts.)
Mount the formatted disk to that mount point.
```
sudo mount /dev/sdb /mnt/newdisk
```
Use lsblk again to see the mount point.
```
lsblk
```
You should now see /mnt/newdisk listed under the MOUNTPOINTS column for /dev/sdb (or loop4).
Optionally, check the file system type with df -hT.
```
df -hT /mnt/newdisk
```
This command will show you the filesystem type (ext4 in this case), size, used space, and available space for your newly mounted disk.

By performing these steps, you explicitly confirm that the disk has been formatted correctly and is now accessible through the file system.

The lab steps will likely guide you through these next actions. Just follow along, and if you have any questions about creating the mount point or mounting, feel free to ask!