Re: Upgrade 9.5 cluster on Ubuntu 16.04

Logical way – dump/restore.

Bringing PGDATA physically may lead to corrupted indexes due to glibc
version changes. 16.04 -> 18.04 shouldn't cause it, but it may. You can
check btree index with amcheck and GIN indexes with a patched version of it
(some backporting would be needed). You can find examples here:
https://gitlab.com/-/snippets/2001962

But back to the question, if you do dump/restore, indexes will be freshly
created, on new machine - therefore there is no question about corruption
for them. I'd choose this path in your situation.

On Thu, Sep 2, 2021 at 10:38 AM Vano Beridze <vanuatoo(at)gmail(dot)com> wrote:

> Hello,
>
> I've got 2 VMs with Postgresql 9.5 cluster with streaming replication.
> VMs have Ubuntu 16.04.
> I would like to upgrade Ubuntu and Postgresql to newer versions.
> Ubuntu 16.04 supports upgrading to 18.04.
> What is the safest way to upgrade Postgresql cluster along with it?
> The database is not big and I can afford completely shutdown the cluster
> during the upgrade.
>
> What would you suggest?
>
> Kind regards,
> Vano
>