Removing an Existing OS from a Switch

This appendix provides information on how to uninstall the OS from a switch.

Reverting from DMF (Switch Light OS) to EOS - 7050X3 and 7260CX3

This appendix details the procedure to revert the Arista 7050X and 7260X Series switch from Switch Light OS to EOS.

Procedure

To revert from SWLOS to EOS, complete the following steps:

  1. Connect to the switch via a serial connection and confirm that a SWLOS is installed. The serial console output of the switch should approximate the following example. 
    Connected to 10.240.130.2.
Escape character is '^]'.
Switch Light OS SWL-OS-DMF-8.2.0(0), 2022-03-25.05:22-fdf3fa6
Site1-F1 login:
  2. Log in to the switch via a serial connection and reboot the switch.
  3. Enter Aboot by interrupting the boot process by pressing Control-C. 
    Watchdog enabled, will fire in 2 mins
CBFS: 'Master Header Locator' located CBFS at [200:ffffc0)
CBFS: Locating 'normal/romstage'
CBFS: Found @ offset 5b3d40 size 7b7c
Aboot 9.0.3-4core-14223577
Press Control-C now to enter Aboot shell
^CWelcome to Aboot.
Aboot#
  4. Once in Aboot, change the directory to /mnt/flash. 
    Press Control-C now to enter Aboot shell
^CWelcome to Aboot.
Aboot#
Aboot# cd /mnt/flash
Aboot# pwd
/mnt/flash
Aboot#
  5. List the files under the /mnt/flash directory and check the boot-config file for current swi. 
    Aboot# pwd
/mnt/flash
Aboot# ls
AsuFastPktTransmit.log SsuRestoreLegacy.log lost+found
EOS-4.23.3M.swi aboot-chainloader.swi onl
Fossil boot-config persist
SWL-INSTALLER.swi debug schedule
SsuRestore.log fastpkttx.backup startup-config
Aboot#
Aboot# cat boot-config
SWI=flash:aboot-chainloader.swi
Aboot#
  6. Edit the boot-config file to point to the existing EOS swi under the /mnt/flash directory. 
    Aboot# vi boot-config
Aboot#
SWI=flash:aboot-chainloader.swi
~
SWI=flash:/EOS-4.23.3M.swi
~
Aboot# cat boot-config
SWI=flash:/EOS-4.23.0F.swi
  7. Reboot the switch. The switch should boot up with the EOS image. 
    Aboot# reboot
Requesting system reboot
Press Control-C now to enter Aboot shell
Booting flash:/EOS-4.23.0F.swi
[ 13.231125] Starting new kernel
starting version 219
Failed to apply ACL on /dev/kvm: Operation not supported
Welcome to Arista Networks EOS 4.23.0F

Reverting from DMF (EOS) to EOS - 7280R

This appendix details the procedure to revert the Arista 7280R Series switch from DMF EOS to UCN EOS.

Procedure

To revert from DMF (EOS) to UCN EOS, complete the following steps:
  1. Log in to the switch via a serial connection and reboot the switch. 
    Connected to 10.240.130.2.
Escape character is '^]'.
SAND-3 login: admin
Output to this terminal is being recorded for diagnostic purposes.
Note that only output that is visible on the console is recorded.
SAND-3>en
SAND-3#reload
! Signing certificate used to sign SWI is not signed by root certificate.
Proceed with reload? [confirm]
  2. Enter Aboot and interrupt the boot process by pressing Control-C. 
    agesawrapper_amdinitearly() returned AGESA_SUCCESS
Watchdog enabled, will fire in 2 mins
CBFS: 'Master Header Locator' located CBFS at [200:ffffc0)
CBFS: Locating 'normal/romstage'
CBFS: Found @ offset 5b3d40 size 7b7c
Aboot 9.0.3-4core-14223577
Press Control-C now to enter Aboot shell
^CWelcome to Aboot.
Aboot#
  3. Once in Aboot, change the directory to /mnt/flash. 
    Press Control-C now to enter Aboot shell
^CWelcome to Aboot.
Aboot#
Aboot# cd /mnt/flash
Aboot# pwd
/mnt/flash
Aboot#
  4. List the files under the /mnt/flash directory and check the boot-config file for current swi. 
    Aboot# pwd
/mnt/flash
Aboot# ls
AsuFastPktTransmit.log
EOS-4.25.2F.swi
EOS-4.27.2F-26021868.uppsaladmfrel-x86_64.swi
EOS-4.27.2F-26021868.uppsaladmfrel-x86_64.swi.tmp
Fossil
SsuRestore.log
SsuRestoreLegacy.log
boot-config
debug
fastpkttx.backup
x86_64
lost+found
persist
schedule
startup-config
zerotouch-config
ztn-boot-info
Aboot#
Aboot# cat boot-config
SWI=flash:/EOS-4.27.2F-26021868.uppsaladmfrel-x86_64.swi
Aboot#
  5. Remove the startup-config file and edit the boot-config file to point to the existing EOS swi under the /mnt/flash directory. 
    Aboot# rm -rf startup-config
Aboot# vi boot-config
Aboot#
SWI=flash:aboot-chainloader.swi
~
SWI=flash:/EOS-4.25.2F.swi
~
Aboot# cat boot-config
SWI=flash:/EOS-4.25.2F.swi
  6. Reboot the switch. The switch should boot up with the EOS image. 
    Aboot# reboot
Requesting system reboot
Press Control-C now to enter Aboot shell
Booting flash:/EOS-4.25.2F.swi
[ 13.231125] Starting new kernel
starting version 219
Failed to apply ACL on /dev/kvm: Operation not supported
Welcome to Arista Networks EOS 4.25.2F

Removing the existing OS from a Switch

Some switch platforms may have a preexisting operating system (OS) installed. When installing the Switch Light OS on top of an existing OS, there is a chance of failure. To avoid this issue, first uninstall any existing OS on the switch.

For example, to use a Dell switch with Force 10 OS (FTOS) pre-installed, remove FTOS before installing Switch Light OS. If FTOS is not first deleted, Switch Light installation may fail.

When you boot the switch, if only ONIE options are listed in the switch GNU GRUB boot menu, the switch does not have an existing OS installed. The following example shows the prompts that indicate no OS is installed on the switch.

Example 4: ONIE Prompts for a switch without an OS installed. 
GNU GRUB version 2.02~beta2+e4a1fe391
+----------------------------------------------------------------------------+
|*ONIE: Install OS |
| ONIE: Rescue |
| ONIE: Uninstall OS |
| ONIE: Update ONIE |
| ONIE: Embed ONIE |
| |
+----------------------------------------------------------------------------+

If the switch prompt looks something like this, skip this section and proceed directly to the following section to install Switch Light OS.

Procedure

To delete FTOS from a Dell switch, complete the following steps:

  1. Confirm an OS is installed on the switch.
  2. Another OS exists if other options besides ONIE appear in the boot menu. The following example shows the options provided by FTOS installed on a Dell switch. 
    GNU GRUB version 2.02~beta2+e4a1fe391
+----------------------------------------------------------------------------+
|*FTOS |
| FTOS-Boot Line Interface |
| DIAG-OS |
| ONIE |
| |
+----------------------------------------------------------------------------+
  3. After the switch has booted and the prompt for FTOS is displayed, change to enable mode. 
    DellEMC>enable
The SupportAssist EULA acceptance option has not been selected. SupportAssist can be
enabled once the SupportAssist EULA has been accepted. Use the: 'support-assist activate
' command to accept EULA and enable SupportAssist.
DellEMC#Feb 13 22:36:44 %STKUNIT1-M:CP %SEC-4-ENABLE_PASSW_NOT_CONFIGURED: Enable password
is required for authentication but
not configured (by default from console)
Feb 13 22:36:44 %STKUNIT1-M:CP %SEC-5-AUTHENTICATION_ENABLE_SUCCESS: Enable authentication
success on console
DellEMC#
  4. Reload the switch, do not save the configuration, and confirm the operation when prompted. 
    DellEMC# reload
System configuration has been modified. Save? [yes/no]: no
Proceed with reload [confirm yes/no]: yes
    The following messages are displayed. 
    Feb 13 22:37:17 %STKUNIT1-M:CP %CHMGR-5-RELOAD: User request to reload the chassis syncing
disks... done
unmounting file systems...
  5. To uninstall the OS, choose ONIE from the GNU GRUB boot menu, as shown in the following example. 
    GNU GRUB version 2.02~beta2+e4a1fe391
+----------------------------------------------------------------------------+
|*FTOS |
| FTOS-Boot Line Interface |
| DIAG-OS |
|*ONIE |
| |
+----------------------------------------------------------------------------+
    The ONIE submenu is displayed, as shown in the following example. 
    GNU GRUB version 2.02~beta2+e4a1fe391
+----------------------------------------------------------------------------+
| ONIE: Install OS |
| ONIE: Rescue |
|*ONIE: Uninstall OS |
| ONIE: Update ONIE |
| ONIE: Embed ONIE |
| EDA-DIAG |
| |
+----------------------------------------------------------------------------+
  6. From the ONIE submenu, choose ONIE Uninstall OS.

    The uninstall process can take up to 15 minutes. After completion, the switch will automatically reboot.

    The OS Uninstall log is displayed, starting with information about the existing OS, as shown in the following example. 
    ONIE: OS Uninstall Mode ...
Version : 3.27.1.1
Build Date: 2016-09-07T16:44-0700
Info: Mounting kernel filesystems... done.
Info: Mounting ONIE-BOOT on /mnt/onie-boot ...
<SNIP>
    The following messages are displayed when the process is complete and the switch reboots. 
    Requesting system reboot
sd 4:0:0:0: [sda] Synchronizing SCSI cache
reboot: Restarting system
reboot: machine restart
Note: FTOS was successfully uninstalled if only the ONIE options are shown after the switch reboots, as in Example 1 at the beginning of this section. When you see only ONIE options, proceed to the next section to install Switch Light OS.