[CentOS] Is ext4 safe for a production server?

[Ian Forde]

On Sat, 2009-12-05 at 22:47 -0500, Brian Mathis wrote:
> On Sat, Dec 5, 2009 at 10:20 AM, Miguel Medalha <miguelmedalha at sapo.pt> wrote:
> > I am about to install a new server running CentOS 5.4. The server will
> > contain pretty critical data that we can't afford to corrupt.
> >
> > I would like to benefit from the extra speed and features of a ext4
> > filesystem but I don't have any experience with it.
> > Is there some member of the list who can enlighten me on whether ext4 is
> > mature enough to be used on a production server without too much risk?
> >
> > Thank you!
> >
> 
> Regardless of the technical issues offered here, ask yourself this: Do
> you really want to be experimenting with a new file system on a
> production server with "pretty critical data"?  Since you asked about
> "too much risk", I think you already answered the question.
> 
> Any sane process would involve installing it on a low priority test
> server, running for a while to see how it goes, and learning about new
> features or tools.  After you've done that on a few lower priority
> servers, for maybe a year or so, then you might start to _think_ about
> using it on a production server like this.
> 
> My guess is that any additional speed can come from tuning other areas
> of your server and disk subsystem.  What hardware do you have?  What
> kind of disks?  Using RAID?  What level?  Have you looked into
> aligning your partitions with the RAID blocks?  I'm sure that some of
> the hardcore disk I/O people on the list can ask better questions and
> give more meaningful recommendations.

Funny that - that's the kind of answer I was hoping to see on this list.
The key issue was the fact that it's a production server.  As a data
point, I've been using mythtv at home for about 6 years.  (Has it really
been that long? Wow!)  During that time, I've been using XFS filesystems
for media storage for about the last 4 or 5.  I haven't had a problem
with it yet, though that doesn't preclude the possibility of it
occurring at some later date.

(Even, now that I've written this, it may fail several seconds from now,
given that I may have jinxed it!)

Anyhoo - due to this experience with it for my data at home which is
constantly been written and rewritten - (mythtv is pretty intensive on
systems - run it for a few years and BELIEVE ME - you'll find out where
the weak points in various OS components are...) I've found XFS safe
enough to use at work on production database servers.

It works for me.  It may not for you, but I'm happy so far.

Again - this may all change tomorrow, but YMMV, as there's no such thing
as software liability, and open source may eat your cat, make your dog
toss its cookies on your lap, and cause the universe to unspool itself
in your Wheaties tomorrow.  We all take our chances, and it's a matter
of how much risk we're willing to shoulder.  As I said, I went through
my process and deemed it acceptable...

	-I