Red Hat (NYSE:RHT) is out with the second major update to its flagship Red Hat Enterprise Linux (RHEL) distribution release. The RHEL 6.2 release provides improved resource management, virtualization and storage capabilities.
RHEL 6 first debuted in November 2010 and was updated in May 2011 with the RHEL 6.1 release. One of the major changes in the RHEL 6.x series over the previous RHEL 5.x branch is support for cgroups (control groups) to control system resources.
“Cgroups debuted in RHEL 6.0, so the concept isn’t new but what is new in RHEL 6.2 is the ability to set capacity limits,” Tim Burke, vice president of Linux Engineering at Red Hat, told InternetNews.com.
Burke explained that previously the way cgroups worked was with ratios for capacity, for example setting a 40 percent of CPU policy. He noted that the trouble with this approach is that if, for example, there were three virtual guests running on a system, each controlled with a cgroup setting for one-third capacity, if two systems were idle, the third could consume all of the systems resources. With the new ability to specify capacities for I/O rates, CPU cycles and the like, there is now a bounded ceiling.