I think they meant non-catastrophic (no pun intended). From what I can tell, individual files can get corrupted when opened with O_DIRECT, but the filesystem st

I think they meant non-catastrophic (no pun intended). From what I can tell, individual files can get corrupted when opened with O_DIRECT, but the filesystem structure will never fail. From the link in https://news.ycombinator.com/item?id=38591444 https://news.ycombinator.com/item?id=38591444 : > file position is not updated after direct IO write and thus [we] direct IO writes are ending in wrong locations effectively corrupting data. This may be a major problem for hypervisors using ext4-backed disk images. It wouldn't surprise me if qemu opens image files with O_DIRECT by default, but it would surprise me if professional shops were using ext4 as the backing store rather than a provisioning abstraction layer like dm_thin. Still, anyone using kvm on top of ext4 must not be having a good day.