Thanks for catching that. Typo on my end. Now I am getting this. Performing Consistency Checks on Old Live Server ------------------------------------------------ Checking cluster versions ok old and new pg_controldata WAL segment sizes are invalid or do not match Failure, exiting I found the setting in the current version of the instance via "show all" as "wal_segment_size | 16MB". I guess my new instance should be "16MB" as well when running this "initdb --wal-segsize=16 -D /hostname/pg/NewInstance/data"? -----Original Message----- From: Tom Lane <tgl@xxxxxxxxxxxxx> Sent: Friday, December 18, 2020 4:55 PM To: Lu, Dan <Dan.Lu@xxxxxxx> Cc: pgsql-general@xxxxxxxxxxxxxx Subject: Re: Upgrade check failed from 11.5 to 12.1 "Lu, Dan" <Dan.Lu@xxxxxxx> writes: > I am trying to upgrade an instance of PostgreSQL in unix from 11.5 to 12.1. > UNIX:> pg_upgrade -d /hostname/pg/dpoc/data -D /hostname/pg/dpoc/data > -b /hostname/pg/PostgreSQL-11.5/bin -B > /hostname/pg/PostgreSQL-12.1/bin -p 5432 -P 9432 -c -v No, you can't use the same directory to hold old and new versions at the same time. After you're done with the upgrade, you could move the new data directory to be where the old one had been. regards, tom lane ________________________________ IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.