Oracle 11g, OL 6 and ext4

Question

Now that Oracle Linux 6 has been certified for Oracle 11gR2, does this also include the use of the ext4 file system?
I'm asking because I found database performance and block corruption warnings searching in Google, but perhaps this only applied to early implementations of ext4 or were simply wrong assertions. I imagine that certification includes ext4, but just to be sure, is there still a reason to be concerned about it?

Answer 1

Dude wrote:
Concurrent I/O seems to be a topic often discussed when comparing XFS with ext4. If I'm not mistaken then ext4 supports concurrent I/O, but there is a performance penalty compared to XFS, i.e. fragmentation. However, I have not found any information outlining that this was a new issue introduced with ext4.
Apparently people are storing Oracle datafiles under ext3 without problems. The ext4 filesystem is the successor of ext3 and ext2, providing more features and robustness. How performance issues of Oracle DB pertain to ext4 is probably subject to errata and updates.
From what I can gather, ASM (ACFS), or OCFS2 in a RAC environment are the best options under Linux. Performance results will also depend on the underlying storage technology, for instance, caching, SSD or conventional rotary devices.It supports concurrent reads, not writes so if you're running a warehouse type database where it's mostly reads, you'd be fine but if you're doing a lot of writes, you should consider other options (assuming you care about latency and performance).
Personally, I think ASM is the way to go these days for Oracle DBs and you're right, there are a ton of factors to consider when architecting your ASM configs. For example, Oracle suggests putting all your database disks in one huge diskgroup because they claim that performance is better in that case, though I've run quite a lot of tests over the last couple years suggesting otherwise. At the end of the day, most people don't care about performance (though they may say otherwise) and certainly don't take the time to do much tuning. My situation was a bit different due to the nature of the business but even Jim Williams and some of the other folks on the ASM team didn't seem to have initially gone as in-depth as I may have when it came to tuning.
The best thing you can do is run your own tests with tools like fio, orion, swingbench, etc. and figure out if the performance is acceptable based on your needs.