Big Bang on the Network

The extended network capabilities of the system are far more apparent for RHEL admins than the new default filesystem. In fact, Red Hat has come up with a whole bouquet of innovations: support for 40Gb NICs, including the team driver framework as a replacement for classical bonding; several improvements in the TCP/IP stack; and low-latency sockets, which the modified RHEL kernel also supports.

The team driver [4] in particular is symptomatic of many of the innovations in RHEL 7. Basically, the framework does no more than the previous bonding driver in the kernel, but it does this as a daemon in userland and not in the kernel. The developers expect improved performance on the one hand and less overload in high-availability installations  – the classic targets for bonding setups  – on the other.

Additionally, admins will be able to keep time far more accurately with RHEL  7, which replaces the classic ntpd with the specially built Chrony [5] and with PPTv2 support thrown in. PPT (Precision Time Protocol) is a standard for more precisely synchronized clocks than is the case with NTP. Red Hat claims the deviation is just a few microseconds.

Cloud!

In the new version of RHEL, Red Hat is putting its money on the concept of "architecture for everything." Several new functions make it clear that Red Hat Enterprise Linux 7 wants to be a big player in the cloud.

One of the arguments is the official, factory support for Docker. In the cloud environment, the current focus is on the container manager itself [6]. Basically, Docker is an extension of the Linux container format that makes it easier to create and distribute application containers.

The fact that docker enjoys official support in the RHEL release is noteworthy, because Docker itself has not been around for a particularly long time, and Red Hat is usually very careful when it comes to new features. In the normal case, a project first has to prove its value before Red Hat decides to provide support for the product for many years.

The primary objective of Docker on RHEL is to operate virtual systems without the overhead of a fully virtualized computer. In other words: Docker containers require significantly less in terms of resources than KVM-based virtual machines.

Hypervisor Improvements

Red Hat also has much to offer admins who need classic virtualization. The vendor still gives Xen the cold shoulder and relies exclusively on KVM, which is not surprising given that Red Hat swallowed up the KVM inventor Qumranet.

This situation does restrict your options if you want to use Red Hat as a host. Things look better if you want to use RHEL 7 as a guest in a virtualization environment: It comes equipped with kernel drivers for various hypervisor suites. For use with VMware, there's now even a free equivalent of VMware's tools in the form of open-vm-tools, which should make running Red Hat guests on VMware hypervisors a smooth process.