Mark Mielke wrote:
Can you be more specific? I am using ext4 without problems than I have discerned - but mostly for smaller databases (~10 databases, one almost about 1 Gbyte, most under 500 Mbytes).
Every time I do hear about ext4, so far it's always in the context of something that doesn't work well--not hearing about improvements yet. For example, there was a thread on this list earlier this month titled "8.4.1 ubuntu karmic slow createdb" that had a number of people chime saying they weren't happy with ext4 for various reasons.
Also, I have zero faith in the ability of the Linux kernel development process to produce stable code anymore, they're just messing with too many things every single day. Any major new features that come out of there I assume need a year or two to stabilize before I'll put a production server on them and feel safe, because that this point a "stable release" means nothing in terms of kernel QA. Something major like a filesystem introduction would be closer to the two year estimate side. We're not even remotely close to stable yet with ext4 when stuff like http://bugzilla.kernel.org/show_bug.cgi?id=14354 is still going on. My rough estimate is that ext4 becomes usable and free of major bugs in late 2010, best case. At this point anyone who deploys it is still playing with fire.
File systems failures have been pretty rare for me lately, so it's hard to say for sure whether my setup is really running well until it does fail one day and I find out.
All of the ext4 issues I've heard of that worry me are either a) performance related and due to the barrier code not doing what was expected, or b) crash related. No number of anecdotal "it works for me" reports can make up for those classes of issue because you will only see both under very specific circumstances. I'm glad you have a good backup plan though.
-- Greg Smith 2ndQuadrant Baltimore, MD PostgreSQL Training, Services and Support greg@xxxxxxxxxxxxxxx www.2ndQuadrant.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
