If you needed a demonstration that Oracle is not CentOS, then look no further than the fact that only two weeks after Red Hat announced its Enterprise Linux 6.1 update, software giant Oracle has kicked out its Linux 6.1 clone. This is despite Red Hat's attempts to slow down the RHEL cloners and others – such as Oracle and the former Novell – that offer technical support for RHEL distributions.
Oracle announced in a blog posting last week that Oracle Linux Release 6 Update 1 was available for download for 32-bit x86 and 64-bit x64 desktop and server platforms. Perhaps seeing the writing on the wall and that Red Hat would eventually cut off access to the individual Linux patches to the kernel that make up each subsequent release, Oracle said last fall that it would be spinning its own Linux kernel for its clone of RHEL because Red Hat wasn't moving fast enough in applying patches and features and because doing so would give it a strategic advantage in tuning the Oracle Unbreakable Linux kernel to its specific systems when running Oracle middleware, database, and application software.
CentOS is still back at the RHEL 5.6 level and is working to get its clone of RHEL 6.0 out the door, perhaps this month if the development calendar is to be trusted. RHEL 6.0 came out last November, of course, and Oracle was able to get its 6.0 rev, despite Red Hat's efforts to slow it down, out the door in early February.
As with the Oracle Linux 6.0 release, Oracle's own Unbreakable Linux Kernel is installed and enabled by default with Oracle Linux 6.1; technically speaking, this is the kernel-uek-2.6.32-100.34.1.el6uek level of the Oracle kernel. If you want full Red Hat compatibility, then you can boot up the kernel-2.6.32-131.0.15.el6 that Oracle distributes with its clone, which is installed as well when Oracle Linux is put on a machine.
Oracle says it has made a number of improvements in its own kernel, including reduced lock contention across the kernel to beef up the performance of big NUMA servers using I/O affinity. Virtual memory and network I/O have also seen performance improvements in the Oracle Linux kernel, and IRQ balancing is also better, the company says. In the Oracle Linux 6.1 release notes, you will see that Oracle tweaked 61 packages from Red Hat's upstream code and removed a few Red Hat-specific items and logos.
Oracle added its own kernel and tools for managing the Oracle Cluster File System 2 file system. There is a slew of updates to network and SCSI drivers, and the kernel also (presumably) includes updates for future Xeon and Opteron processors due later this year, as RHEL 6.1 did. (Oracle did not say, but it makes sense that this would be adopted in parallel with RHEL.)
Oracle has put a bunch of new technologies into tech preview, paralleling Red Hat Enterprise Linux 6.1, including the btrfs and XFS file systems, FS-Cache, and Linux containers.
Oracle strongly recommends that customers start with a fresh install of Oracle Linux 6.1 if they are jumping from a prior major version of Ellison's Linux to this one, even though the Anaconda installer will technically support an upgrade. Upgrades from beta releases to the production 6.1 release are not supported. You can download RPM packages of Oracle Linux 6.1, the source RPMs, or ISO images through Oracle's E-Delivery site. ®