Thank you for clarification. We did it and right now process is in progress. We assume that it could take a while any experience how many hrs?
Taking into account that server is pretty fast (like 4 CPUs) and WAN channel is about 100Mbit.
p.s. In any case we'll report the results here. It might help other users...
It has to rescan the blockchain, which can take a while. Honestly, I have no estimates as I haven't had to do a rescan in a while. It shouldn't take more than a few hours to complete. Once it is done, the bitcoind will be used normally. There is no need to restart the program and it shouldn't stop itself.