On Tue, 18 Aug 2020 at 19:10, Howard Chu hyc@symas.com wrote:
ext4 with data=journal should never be used, it hides unrecoverable fsync errors, as discussed here https://www.usenix.org/conference/atc20/presentation/rebello (but also see my notes on their work, their testing methods aren't quite right https://twitter.com/hyc_symas/status/1284689627295682563 )
Also, ext4 with data=journal is just way too slow. For dedicated processing workloads you're better off with LMDB on a raw block device, no filesystem at all.
But it seems that raw block devices can reorder writes. Are you suggesting using a raw block device for sync writes?
That makes me hopeful that ext4 with data=journal could be a good option.
It's fine if you don't care about I/O errors.
Thank you. It's rather incredible where file systems are after all these years.