Hey there,

Sorry to hear that you're having issues getting this disk mounted to your Linode.

It looks like what you will need to do is create a mount point for this disk and manually mount the newly added disk. Once the mount point is created you should be able to add an entry to your /etc/fstab file to ensure that this disk is persistently available after reboots. The general concept of the process that you're going to want to follow is outlined below. In this example we are assuming that the newly added disk is positioned in /dev/sec:

Create a mount point for this disk

 sudo mkdir /disk 
      or 
 sudo mkdir /mnt/disk 

Mount the disk to the mount point

 sudo mount /dev/sdc /disk
       or 
 sudo mount /dev/sdc /mnt/disk

At this point the disk should be available to write data to. You can access this disk by changing directory to the disks mount point. In order to make this disk persistent you will need to edit the primary filesystems filesystem table. You can follow the instructions below to make this change.

Edit /etc/fstab

 sudo nano (or whatever text editor you like) /etc/fstab

Add the following lines to the bottom of this file

 /dev/sdc          /disk          ext4
      or
 /dev/sdc          /mnt/disk          ext4

Once you have one of these lines added to the /etc/fstab configuration you can save the file and reboot your Linode to verify that the disk is available on it's mount point.

I hope this information helps you get this disk mounted properly and makes it accessible for you. If you have any questions or run into any issues feel free to open a support ticket and we should be able to assist you with this process.