Re: pg_upgrade: can I use same binary for old & new?

On Sat, Jul 5, 2025 at 2:24 PM <pf(at)pfortin(dot)com> wrote:

> On Sat, 5 Jul 2025 11:11:32 -0700 Adrian Klaver wrote:
>
> >On 7/5/25 09:52, Pierre Fortin wrote:
>
> >> Wanting to upgrade from:
> >> PostgreSQL 15.13 on x86_64-mageia-linux-gnu,
> >> compiled by gcc (Mageia 15.1.0-1.mga10) 15.1.0, 64-bit
> >> to:
> >> PG 17.5
> >>
> >> Way back, I was able to use -k|--link option on pg_upgrade (PG13 to
> PG15);
> >> but since then:
> >>
> >> - my DB has grown to over 8TB
> >
> >How did you measure above?
>
> # du -sb /var/lib/pgsql/data
> 8227910662297 /var/lib/pgsql/data
>
> >> - even with ~70TB, I don't have enough contiguous disk space to
> >> dump/restore
> >
> >What was the pg_dump command?
>
> Didn't try given:
> $ df /mnt/db
> Filesystem Size Used Avail Use% Mounted on
> /dev/sdh1 17T 13T 3.0T 82% /mnt/db
>
> I suppose I could dump each of the 1408 objects to various available
> drives; but given my previous experience with PG13 to PG15 using --link
> which took seconds; I'm hoping to avoid wasting time (at my age, hours
> matter).
>

There's something you're not telling us. The whole point of "pg_upgrade
--link" is an in-place upgrade. It might use a few extra GB of disk space
for when it backs up the PG15 schema and restores it to PG17. Thus, why
are you complaining about running out of disk space?

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