Re: Filesystem Direct I/O and WAL sync option - Mailing list pgsql-performance

From Heikki Linnakangas
Subject Re: Filesystem Direct I/O and WAL sync option
Date
Msg-id 468A65F5.8020800@enterprisedb.com
Whole thread Raw
In response to Filesystem Direct I/O and WAL sync option  (Dimitri <dimitrik.fr@gmail.com>)
Responses Re: Filesystem Direct I/O and WAL sync option  (Dimitri <dimitrik.fr@gmail.com>)
Re: Filesystem Direct I/O and WAL sync option  ("Jim C. Nasby" <decibel@decibel.org>)
List pgsql-performance
Dimitri wrote:
> I'm very curious to know if we may expect or guarantee any data
> consistency with WAL sync=OFF but using file system mounted in Direct
> I/O mode (means every write() system call called by PG really writes
> to disk before return)...

You'd have to turn that mode on on the data drives as well to get
consistency, because fsync=off disables checkpoint fsyncs of the data
files as well.

--
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com

pgsql-performance by date:

Previous
From: Dimitri
Date:
Subject: Filesystem Direct I/O and WAL sync option
Next
From: Dimitri
Date:
Subject: Re: Filesystem Direct I/O and WAL sync option