For example, I will take several MA5608T with different firmware versions in which only one MCUD1 control board is installed and install the second MCUD1 for backup. The MCUD1 installation process is similar for MA5608 and MA5800-X2.
Once on one OLT MA5608T there was a CRC memory failure on the MCUD1 board, because of which the OLT switched to the backup, and the main one became the backup (by the way, there were no more errors, so we left it as a backup), the only thing that needed to be done was for the worker to switch the SFP+ module to the active board. After this failure, I ordered new MCUD1 boards on Alibaba for the Huawei MA5608T OLT, which had only one MCUD1 board, because if it stopped working, I would have to spend a lot of time updating the firmware of the new board and copying the configuration.
If the OLT already has one MCUD1 board, then installing the second backup one is very simple, It is enough to insert it into the slot hot while the OLT is running, after which it is strictly forbidden to remove it from the slot and turn off the OLT power, since the board will start updating the firmware and fully synchronizing with the main board, all this takes up to 40 minutes or less.
During the synchronization process, the MCUD1 board status will be either Failed or Config until it completely duplicates the main one. You can view the status like this:
display board 0
display board 0/3
After the status of H901MPSA (MCUD1) is Standby_normal, it is necessary to save the configuration, saving is performed on both boards simultaneously:
save
At this point, the process of installing the backup MCUD1 can be considered complete.
See also my articles:
Configuring Huawei MA5608T
How to set up Huawei MA5800