From: Michael Paquier <michael@paquier.xyz>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Cc: Bruce Momjian <bruce@momjian.us>
Subject: Re: file cloning in pg_upgrade and CREATE DATABASE
Date: Tue, 17 Jul 2018 15:58:34 +0900
Message-ID: <20180717065833.GG3388@paquier.xyz> (raw)
In-Reply-To: <0241eae2-2f31-3667-200d-ae0e2293f692@2ndquadrant.com>
References: <bc9ca382-b98d-0446-f699-8c5de2307ca7@2ndquadrant.com>
<20180319070636.GA4633@paquier.xyz>
<20180319071415.GB4633@paquier.xyz>
<20180320025849.GB4963@paquier.xyz>
<678999c6-0967-d22a-e7d1-2a3aff83a77b@2ndquadrant.com>
<20180323171650.GI1302@momjian.us>
<4a62b089-ee93-50ee-f3f7-43c67b4c8ea4@2ndquadrant.com>
<0241eae2-2f31-3667-200d-ae0e2293f692@2ndquadrant.com>
On Wed, Jun 06, 2018 at 11:58:14AM -0400, Peter Eisentraut wrote:
> <para>
> The setting <literal>always</literal> requires the use of relinks. If
> they are not supported, the <application>pg_upgrade</application> run
> will abort. Use this in production to limit the upgrade run time.
> The setting <literal>auto</literal> uses reflinks when available,
> otherwise it falls back to a normal copy. This is the default. The
> setting <literal>never</literal> prevents use of reflinks and always
> uses a normal copy. This can be useful to ensure that the upgraded
> cluster has its disk space fully allocated and not shared with the old
> cluster.
> </para>
Hm... I am wondering if we actually want the "auto" mode where we make
the option smarter automatically. I am afraid of users trying to use it
and being surprised that there is no gain while they expected some. I
would rather switch that to an on/off switch, which defaults to "off",
or simply what is available now. huge_pages=try was a bad idea as the
result is not deterministic, so I would not have more of that...
Putting CloneFile and check_reflink in a location that other frontend
binaries could use would be nice, like pg_rewind.
--
Michael
Attachments:
signature.asc (application/pgp-signature, 832B) download
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-hackers@postgresql.org
Cc: michael@paquier.xyz, peter.eisentraut@2ndquadrant.com, bruce@momjian.us
Subject: Re: file cloning in pg_upgrade and CREATE DATABASE
In-Reply-To: <20180717065833.GG3388@paquier.xyz>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox