Network Updates

The changes affecting the network are not quite as extensive. The updated version of firewalld is a bit faster. Users can also use connection tracking for services that do not use a default port and therefore need custom help services. As of RHEL 8.2, the firewall rules can also use standard kernel auxiliary modules. Last but not least, firewalld now uses the libnftables JSON interface for the nftables subsystem.

More eBPF in the Kernel

The kernel-integrated eBPF virtual machine plays a role in the Linux kernel updates from RHEL 8.2. The distribution supports three components that rely on eBPF.

The BPF Compiler Collection (BCC) lets you build various programs based on eBPF that perform efficient kernel tracing. At the same time, BCC also has its own tools to keep an eye on the performance and data throughput of Linux systems. The BCC library supports the development of tools similar to those already in the BCC's baggage. Last but not least, eBPF supports a traffic control subsystem of the Linux kernel.

Filesystems, HA, and Clusters

The new release also includes improvements for filesystems, high availability (HA) configurations, and clusters. LVM now supports the caching method dm-writecache. XFS comes with support for writeback, taking cgroups into account. GlusterFS now makes use of the copy_file_range() system call implemented in FUSE, which allows for faster copying of data.

For clusters and HA setups, Red Hat provides the pcs command-line tool, which has been given some new options in RHEL 8.2. Among other things, the options let you reveal the relationships between resources, disable a resource without endangering other resources, and show the status of a primary site and a recovery site cluster at the same time.