[the8472]

YOLO mountflags for ext4 that minimize synchronous writes:

    data=writeback,journal_async_commit,lazytime,nobarrier,commit=99999

Good for caches, scratch space, build dirs and anything that can be rebuilt from other data but it'll get corrupted during any non-graceful shutdown.

overlayfs offers an even more aggressive mount option "volatile" which ignores all O_SYNC or fsyncs, but no other filesystem exposes that tradeoff.

[Joel_Mckay]

Have a look at dedicated external journal disk performance for ext4. It actually is pretty fast, and relatively safe.

I find performance wise, a logging fs like f2fs is actually not as terrible as one would expect for most use-cases:

UUID=abc /home f2fs defaults,noatime,nodiratime,noquota,discard,nobarrier,inline_xattr,inline_data 0 2