Deploy and manage the virtual private servers in your IDrive® Compute account from the web console.

Information Included in the Article

• Rescue an Instance
• Mount a Rescued Instance Disk
• Unrescue an Instance

Rescue an Instance

If an existing instance fails to boot, you can use the rescue mode to safely boot the instance without affecting the data. The faulty instance disk will be mounted on a rescuing OS of your choice to perform the rescue operation.
Follow the steps to rescue an instance: 

1. Sign in to your IDrive^® Compute account.
2. Click the instance you want to rescue.
3. Select Rescue from the LHS menu. 
4. Choose a standard distribution or select a custom image or application stack image from the Images tab.
   
   
5. Click Rescue.
6. Click Rescue in the popup. 
   
   
7. Login to the rescuing OS and the rescued instance disk should be available as an attachment, which can be mounted to perform the rescue operation.

Mount a Rescued Instance Disk

To start a rescue operation, you need to login into the rescuing OS and mount the rescued instance disk to boot the instance securely. You can then use the rescuing OS to access the instance data and troubleshoot the error that was preventing normal instance operations.
Follow the steps to mount the rescued instance disk:

1. Login (SSH) to the rescuing instance.
2. List down the disks attached to the rescuing instance, using lsblk command. 
   

   # lsblk
   NAME  MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
   vda  252:0  0  2.2G 0 disk
   ├─vda1 252:1  0  2.1G 0 part /
   ├─vda14 252:14  0  4M 0 part
   └─vda15 252:15  0  106M 0 part /boot/efi
   vdb  252:16  0  160G 0 disk
   ├─vdb1 252:17  0 159.9G 0 part
   ├─vdb14 252:30  0  4M 0 part
   └─vdb15 252:31  0  106M 0 part

3. Mount the rescued instance disk. In the example above it is “vdb1."    
   

   # mount /dev/vdb1 /mnt

4. In case of any issue during the mount operation, use the parameters "-r", "-o nouuid".
   For example: "mount -r -o nouuid /dev/vdb1 /mnt"
   For other operating systems, ensure that the installed btrfs-progs package has version 4.14 or above.
   

Note: Since the rescuing OS gets the settings of the rescued instance configured at the time of instance creation. Therefore, you will have to use the root password of the rescued instance set during its creation to login.
However, the root password can be changed by accessing the instance via SSH Key.

Unrescue an Instance

Once the rescue operation is performed, you can revert the instance to its normal state by urescuing it.
Follow the steps to unrescue an instance:

1. Sign in to your IDrive^® Compute account.
2. Click Actions against the instance and select Unrescue. 
   
   
   
   
3. Click Unrescue in the popup.