Horton

Re: Postgres, fsync, and OSs (specifically linux)

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Stephen Frost <sfrost@snowman.net>
Cc: Bruce Momjian <bruce@momjian.us>, Craig Ringer <craig@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2018-04-28T16:08:26Z
Lists: pgsql-hackers 
Hi,

On 2018-04-28 11:10:54 -0400, Stephen Frost wrote:
> When we crash-restart, we also go through and clean things up some, no?
> Seems like that gives us the potential to end up fixing things ourselves
> and allowing the crash-restart to succeed.

Sure, there's the potential for that. But it's quite possible to be
missing a lot of free space over NFS (this really isn't much of an issue
for local FS, at least not on linux) in a workload with rapidly
expanding space usage. And even if you recover, you could just hit the
issue again shortly afterwards.

Greetings,

Andres Freund

Commits

  1. PANIC on fsync() failure.

  2. Fix and improve pg_atomic_flag fallback implementation.