Following OpenZFS 2.4-rc3 from nearly one month ago is now a fourth release candidate for the upcoming OpenZFS 2.4. A few more features and improvements have been squeezed into this release in nearing the stable milestone.

There is now support for default user/group/project quotas including object quotas, support in the Direct IO mode to fallback to lightweight uncached IO when dealing with unaligned writes (wiring O_DIRECT also to Uncached I/O), unified allocation throttling as a new means to reduce vdev fragmentation, and better encryption performance when using AVX2 for AES-GCM. The AVX2 implementation of AES-GCM is being adopted from BoringSSL to help the performance on AMD Zen 3 and similar CPUs for up to an 80% speed-up reported.