Downgrading OS Software

Prior to downgrading software, please make sure the following prerequisites are met.

  1. Log in to the switch via the CLI using the console port.

  2. Backup configuration by following these steps.

    1. Disable paging of CLI output.

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      switch (config)# no cli default paging enable

    2. Display commands to recreate current running configuration.

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      switch (config)# show running-config

    3. Copy the output to a text file.

  1. Log in to your system to obtain its product number.

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    switch (config) # show inventory

  2. Log in to MyMellanoxand download the relevant MLNX-OS version to your system type

  3. Log in to your system via the CLI.

  4. Change to Config mode.

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    switch > enable switch # configure terminal switch (config) #

  5. Delete all previous images from the Images available to be installed prior to fetching the new image.

  6. Fetch the desired software image.

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    switch (config) # image fetch scp://username:password@192.168.10.125/var/www/html/<image_name> 100.0%[#################################################################]

Warning

The procedure described below assumes that booting and running is done from Partition 1 and the downgrade procedure is performed on Partition 2.

  1. Log in to your system via the CLI as admin.

  2. Enter config mode.

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    switch > enable switch # configure terminal

  3. Display all image files on the system.

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    switch (config) # show images Images available to be installed: new_image.img <downgrade version> 2010-09-19 16:52:50 Installed images: Partition 1: <current version> 2010-09-19 03:46:25 Partition 2: <current version> 2010-09-19 03:46:25 Last boot partition: 1 Next boot partition: 1 No boot manager password is set.

  4. Install the fetched image.

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    switch (config) # image install <image_name> Step 1 of 4: Verify Image 100% [#################################################################] Step 2 of 4: Uncompress Image 100.0% [#################################################################] Step 3 of 4: Create Filesystems 100.0% [#################################################################] Step 4 of 4: Extract Image 100.0% [#################################################################]

  5. Display all image files on the system.

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    switch (config) # show images Images available to be installed: new_image.img <downgrade version> 2010-09-19 16:52:50 Installed images: Partition 1: <current version> 2010-09-19 03:46:25 Partition 2: <downgrade version> 2010-09-19 16:52:50 Last boot partition: 1 Next boot partition: 2 No boot manager password is set.

  6. Configure the boot location to be the other (next) partition.

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    switch (config) # image boot next

    Warning

    There are two installed images on the system. Therefore, if one of the images gets corrupted (due to power interruption, for example), in the next reboot the image will go up from the second partition.

    Warning

    If you are downgrading to an older software version which has never been run yet on the switch, use the following command sequence as well.

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    switch (config) # no boot next fallback-reboot enable switch (config) # configuration write

  7. Reload.

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    switch (config) # reload

The system saves a backup configuration file when upgrading from an older software version to a newer one. If the system returns to the older software partition, it uses this backup configuration file.

Important

All configuration changes done with the new software are lost when returning to the older software version.

There are 2 instances where the backup configuration file does not exist:

  • The user has run “reset factory” command, which clears all configuration files in the system

  • The user has run “configuration switch-to” to a configuration file with different name then the backup file

Warning

Note that the configuration file becomes empty if the system is downgraded to a software version which has never been installed yet.

To allow switching partition to the older software version for the 2 aforementioned cases only, follow the steps below.

  1. Run the following command.

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    switch (config)# no boot next fallback-reboot enable

  2. Set the boot partition.

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    switch (config)# image boot next

  3. Save the configuration.

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    switch (config)# configuration write

  4. Reload the system.

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    switch (config)# reload

© Copyright 2023, NVIDIA. Last updated on May 23, 2023.