Performing the Rescue Procedure

3.7.2 Performing the Rescue Procedure

You can use the rescue procedure to recover the Oracle Exadata Storage Server system software.

Connect to the Oracle Exadata Storage Server using the console.
Start the Oracle Exadata Storage Server and select the option to boot into rescue mode.
- On X7 and newer servers, during the initial boot sequence you will see something like the following menu of boot options:
```
      Exadata_DBM_0: CELL_BOOT_trying_HD0
      Exadata_DBM_0: CELL_BOOT_trying_CELLBOOT
      Exadata_DBM_1: CELL_BOOT_in_rescue_mode

      Use the ^ and v keys to change the selection.
      Press 'e' to edit the selected item, or 'c' for a command prompt. 
```
  Note:
  
  The above menu appears for only a short time if there are no inputs. Therefore, to retain the menu, press the up-arrow or down-arrow key immediately when it appears.
  
  In the menu, select Exadata_DBM_1: CELL_BOOT_in_rescue_mode, and then press Enter.
- On X6 and older servers, during the initial boot sequence, you will see something like the following:
```
Press any key to enter the menu
Booting Exadata_DBM_0: CELL_USB_BOOT_trying_C0D0_as_HD1 in 4 seconds...
Booting Exadata_DBM_0: CELL_USB_BOOT_trying_C0D0_as_HD1 in 3 seconds...
Press any key to see the menu.
```
  When you see the above, press any key to enter the boot options menu.
  
  Note:
  
  For older versions of Oracle Exadata System Software, you may see the "Oracle Exadata" splash screen. If the splash screen appears, press any key on the keyboard. The splash screen remains visible for only 5 seconds.
  
  In the boot options menu, select CELL_USB_BOOT_CELLBOOT_usb_in_rescue_mode, and then press Enter.

When prompted, select the option to reinstall the Oracle Exadata System Software. Then, confirm your selection.

For example:

         Choose from the following by typing letter in '()': 
           (e)nter interactive diagnostics shell. 
             Use diagnostics shell password to login as root user 
             (reboot or power cycle to exit the shell), 
           (r)einstall or try to recover damaged system, 
Select: r 
[INFO     ] Reinstall or try to recover damaged system
Continue (y/n) [n]: y

If prompted, specify the rescue root password.
If you do not have the required password, then contact Oracle Support Services.
When prompted, specify whether you want to erase the data partitions and data disks.

Specify n to preserve existing data on the storage server.

If you specify y, you will permanently erase all of the data on the storage server. Do not specify this option unless you are sure that it is safe.
For example:
```
Do you want to erase data partitions and data disks (y/n)  [n]: n
```

When prompted, specify the root password to enter the rescue shell.

If you do not have the required password, then contact Oracle Support Services.

For example:

[INFO     ] You are in the rescue mode.
[INFO     ] Imaging pre-boot phase finished with success.
[INFO     ] Installation will continue after reboot.
[INFO     ] Log in to the rescue shell as root with the rescue (Diagnostic shell) root password.

...

Welcome to Exadata Shell!
Give root password for maintenance
(or press Control-D to continue):

Using the rescue prompt, reboot the storage server to complete the rescue process.
For example:
```
sh-4.2# shutdown -r now
```
The rescue process typically takes between 45 and 90 minutes to complete. The storage server may reboot a few times during the rescue process. An on-screen message indicates when the rescue process is completed. For example:
```
Run validation checkconfigs - PASSED
2020-08-17 18:14:01 -0600 The first boot completed with SUCCESS
```
Finally, the login prompt is also displayed.

Parent topic: Using the Oracle Exadata System Software Rescue Procedure