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Date: Tue, 10 Jun 2025 13:17:05 -0700
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Subject: Re: pg_upgradecluster version 10 to 16 question
From: Adrian Klaver <adrian.klaver@aklaver.com>
To: Jim Cunning <jlcunning46@gmail.com>, pgsql-general@lists.postgresql.org
References: <cb7713f2-8ff9-42eb-a3fa-a89c4dc8257a@gmail.com>
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On 6/10/25 13:14, Adrian Klaver wrote:
> On 6/10/25 13:01, Jim Cunning wrote:
>> I had a Ubuntu 20.04 LTS system with a postgresql version 10 database, 
>> and the system became unbootable.  The database was stored in 
>> /var/lib/postgresql/10/main and I was able to recover the entire 
>> contents of the data in that directory and below.  I now have a system 
>> running ubuntu 24.04 LTS with postgresql version 16.
>>
>> I obviously no longer have a running version 10 server, so I cannot 
>> use pg_dump to retrieve the data.  I have placed the recovered version 
>> files in /var/lib/postgresql/10/main on my new system, alongside the 
>> /var/lib/postgresql/16/main that was created when I installed 
>> postgresql.  I have tried several iterations of the pg_upgradecluster 
>> command, a Python script provided by Ubuntu, but it says it cannot 
>> find the database files.
>>
>> I also see from the postgresql wiki pages that there is a pg_upgrade 
>> utility program, but cannot find in any of the Ubuntu-provided 
>> installation files.  Can anyone provide some guidance on how I might 
>> proceed?
> 
> 1) Do:
> 
> man pg_upgradecluster
> 
> 2) Assuming you used the PGDG repos to install Postgres you can do:
> 
> sudo apt install postgresql-10
> 
> to get a Postgres 10 install. I would move the 
> /var/lib/postgresql/10/main you created out of the way and then move the 
> contents back in to the installed version.

Forgot to say, be sure and retain a copy of the original 10 $DATADIR 
somewhere where you can fetch it should the above not work as planned.

> 
>>
>> Thanks in advance.
>>
> 

-- 
Adrian Klaver
adrian.klaver@aklaver.com