[Dovecot] Best filesystem?

[Timo Sirainen]

On 1.2.2011, at 5.11, Stan Hoeppner wrote:

> This depends on how the dev does his syncs.  If done intelligently, XFS
> performance won't suffer.  In fact, the preferred write method to XFS for high
> performance applications is using O_DIRECT.  Using O_DIRECT, correctly, with
> XFS, actually _increases_ write performance versus going through the buffer
> cache.  So you get the best of both worlds:  higher performance and data
> guaranteed on disk.

O_DIRECT is completely useless for just about every application there is. It was written for Oracle, and I doubt there are many applications outside (SQL) databases that use it at all.

> Read Ted's article I linked.  I didn't misquote him.  The simple point he was
> making is that unless devs specifically use fsync or other calls to guarantee
> their data is on disk, they will suffer data loss with any modern journaling
> filesystem when the power goes out or the system crashes.  You seem to be
> assuming all devs use fsync.  Apparently this is far from reality.

Ted also thinks everyone should be using SQL(ite) database rather than filesystems directly. Many people don't agree.