For the next generation of its flagship enterprise Linux distribution, Red Hat aims to support new cloud technologies while preserving the ways of the seasoned system administrator.
”We’re trying to bring capabilities into the future for our customers who want to do next-generation architectures,” said Mark Coggin, Red Hat senior director of RHEL product marketing. “At the same time, we still have the obligation to deliver against all the core attributes that have made RHEL successful.”
The first public beta of Red Hat Enterprise Linux 7.0, issued Wednesday, incorporates some of the latest technologies in virtualization, storage and interoperability with Microsoft Windows. The company has been working on RHEL 7 for more than three years. It was built from Fedora 19, using the upstream Linux 3.10 kernel.
Containers are one emergent technology RHEL 7.0 embraces. Containers are like virtual machines in that multiple containers, each containing a separate application, can run on a single server. Like VMs, each container is isolated from all the other containers. But unlike VMs, containers all share the same, single OS kernel of the server.
Containers have long been a feature in Oracle’s Solaris Unix distribution, though recently have found favor in the larger Linux community as well, due at least in part to the growing popularity of Docker container technology.
”Customers are recognizing that containers give them a lot of capabilities [to run] lightweight portable applications that have low overhead and easily scale and move across physical and cloud architectures,” Coggin said.
RHEL 7 supports Docker and other Linux containers. It will provide the ability to partition each application container, limiting the amount of CPU, memory and bandwidth resources each uses. To manage these resources, RHEL will use the libvirt toolkit that the distribution has long used to manage virtual machines.
By using libvirt, “we tried to preserve the knowledge base that administrators have learned over many years, so they can use it in RHEL 7 and in the cloud,” said Ron Pacheco, Red Hat senior manager for platform product management.
RHEL 7 is also keeping abreast of new developments in file systems. For the first time, RHEL will use XFS as the default file system. First developed by SGI, XFS is a high-performance journaling file system designed for managing large sets of data and heavy parallel workloads. In RHEL 7, XFS will support up to 50TB of data, and can store blocks of data in sizes up to 1MB, which can help reduce fragmentation as well as time the server spends doing block allocation.
Users wary of switching to the cutting-edge XFS can still use the previous file system, ext4, or another advanced, though still experimental, file system, Btrfs.
Also on the cutting edge in RHEL 7 is some work done to make the KVM (kernel-based virtual machine) hypervisor understand NUMA (non-uniform memory architecture). NUMA configures working memory in large systems so the data resides as closely as possible to the computer processor that uses that data. Recognizing NUMA will allow KVM virtual machines to work close to the bare-metal speed of the server, Pacheco said.
”This may be important for customers who are now trying to consolidate those last mission-critical workloads on bare metal,” Pacheco said. “We want to see their feedback as to whether or not we are obtaining all the performance we are expecting” with the beta release.
For the old-school Linux administrators, who run everything by the command line, RHEL 7 offers a unified CLI (command line interface). RHEL, of course, offers all the standard Unix commands, but now administrators can also type and script Red Hat commands for handling many storage and networking duties from the same shell. Previously, these commands could only be issued through Red Hat’s Storage Manager and Network Manager utilities.
”Admins can just enhance their scripts to take advantage of the unified CLI,” Pacheco said.
Red Hat is also working to bridge the divide in data centers between RHEL servers and Microsoft Windows Servers, so that users can be authenticated for any application on either type of server.
Using Samba 4.1 in RHEL 7, administrators can bridge Microsoft Active Directory domains with the directories based on LDAP (Lightweight Directory Access Protocol). They can also set up a parallel trust zone between Windows and RHEL servers using the RHEL Identity Management software.
”It will simplify the ability for a Linux user to reach services that reside on the Windows domain, such as a printer server,” Pacheco said. RHEL “will also offer the ability for the [Linux] user to automatically be enrolled into an Active Directory domain.”
Finally, RHEL 7 interfaces with OpenLMI, open-source software designed to manage multiple Linux distributions through a single interface.