After reading up on the whole data=ordered fiasco that EXT4 went through and how much support there was on it accommodating "broken" applications, I was surprised that a filesystem that is not guaranteed to write the data before the metadata was chosen as the default in an enterprise linux OS.
https://www.suse.com/communities/conversations/xfs-the-file-system-of-choice/
Has XFS changed to the point where it is on par with the reliability of EXT4 in data=ordered mode or has some other variables changed where this is now a moot point?
Best Answer
Yes, XFS is basically on data=writeback modus operandi. EXT4 is the same, and so NTFS and BTRFS and any modern filesystem.
However, the common "wrong cases" (eg: crash/power loss when truncating a file) are all worked around in the code, so in practice EXT4 and XFS are very stable.
On the other side, many distributions used EXT3 without barriers, which in the wrong situation (eg: powerloss during a journal wrap-around) can totally destroy your filesystem.
In short: XFS is perfectly stable in production scenario, especially on RHEL (and derived) OS where is has many patches and backports from recent kernel releases. For example, while Debian 6.0 XFS performances were quite poor, RHEL 6 was much faster thanks to the delayed logging algorithm implemented in newer kernels and back-ported to RHEL one.