BladeSystem Virtual Connect

VC Firmware upgrade rollback from a previous firmware upgrade without domain deletion

Trusted Contributor

VC Firmware upgrade rollback from a previous firmware upgrade without domain deletion

Lawrence had VC questions on firmware rollback capabilities:




Howdy VC Gurus,


In VC 3.75, it was possible to perform a firmware upgrade rollback from a previous firmware upgrade without domain deletion.  This is noted in the VC 3.75 release notes.


What is the situation with VC 4.01?  Does it still provide this capability or is the roll back procedure back to the old method of deleting the domain and restoring from a backup?  The VC 4.01 release notes do not address the topic of firmware roll back.




From Sandeep:

Firmware upgrade rollback is still supported. You can use VCSU 1.8.1 to downgrade to the previously installed firmware version without deleting the domain.


Reply from Lawrence:

What if the original VC firmware is as old as version VC 3.18 and the customer had to roll back to that version after going to 4.01.  Will that work?


I guess what I’m asking is whether there are any limits to the version of VC that 4.01 can roll back to – I would have thought that the extended VLAN capability would have limited VC roll back to version 3.3x due to that version being the first version to support extended VLANs


Input from Mark:

I will try to explain so that it makes sense and I will paste from the VCSU Release Notes


  • Upgraded from Minimum version of VC Firmware is VC 3.17
  • Upgraded to Minimum version of VC Firmware is VC 3.70
  • VCSU 1.7.0 or higher has to be used to perform both the upgrade and rollback/downgrade of firmware
  • Rollback(downgrade) can only install the previous version of firmware


So if you use VCSU 1.7.1 for example to update FlexFabric modules from 3.18 to 4.01, you will only be able to downgrade/rollback (and keep Domain) if you rollback to VC 3.18

Any other version you attempt to downgrade to (3.30/3.75), you will be informed you must Delete the Domain first.


Any changes that were made in the new firmware do not carry backwards if you perform a rollback to the previous version. So to answer your question if you had VC 3.18 and updated to VC 4.01 and enabled “Extended VLAN” and then performed a rollback to VC 3.18, you would be back to your original configuration on VC 3.18 prior to the upgrade. That goes the same for profile changes, networks, fabrics everything. During the firmware upgrade, a copy of the “Configuration” is stored on the module. It is stored in Flash. If at some point you decided to “rollback” to that previous version of firmware, that “Configuration” will be re-applied after the downgrade. This feature was implemented so that if a customer made a mistake and didn’t want to update the firmware, they could easily rollback without losing the Domain settings.




This feature enables you to downgrade to a previously installed and running version of VC.


The following restrictions apply:

  • • You must be running VC version 3.70 or higher to perform a downgrade.
  • • You cannot downgrade to a VC version lower than v3.17.
  • • A previous upgrade must have been performed on the configuration using VCSU 1.7.0.
  • • All servers in the domain must be powered off.
  • • Multiple, consecutive firmware downgrades are not allowed.
  • • You can downgrade only to the version previously installed and running on the primary module.
  • • The VC configuration, including physical connections, uplink port connections, and module positions in

the enclosure, must be identical to the target downgrade configuration.

  • • The VC credentials must be the same before and after the downgrade. After the downgrade, you cannot

change the password for the account used to perform the downgrade.

  • • The primary E-net module must be in the lowest bay number.


Question from Hoa:

Any drawback/advantage using VCSU 1.8.1 with 3.75 and below?


Comment from Mark:

In my opinion you should always use the latest VCSU as it contain fixes to defects as well as added functionality to support update to latest firmware.

That would be the advantage.




Any other comments or questions?