On Thu, Oct 23, 2025 at 11:21 AM Greg Sabino Mullane <htamfids@gmail.com> wrote:
Acceptable downtime: ~1 day
Logical replication: Not feasible due to the number of schemas, tables, and overall data volume
I'm not sure why this is not feasible. Can you expand on this?
* For a 15 TB database with roughly 1 day downtime, what would be the most reliable approach to migrate from RHEL 7 → RHEL 9 while avoiding collation/index corruption issues?
pg_dump is the most reliable, and the slowest. Keep in mind that only the actual data needs to move over (not the indexes, which get rebuilt after the data is loaded). You could also mix-n-match pg_logical and pg_dump if you have a few tables that are super large. Whether either approach fits in your 24 hour window is hard to say without you running some tests.
Last year. I did a dump/restore of a 4.3TB (inclusive of indices; heavy on poorly-compressible BYTEA) database from RHEL6 + 9.6.24 to RHEL 8 + 14.latest. It took just under 11 hours.
