I’ve recently had the opportunity to talk with a small sample of SLES 11 and RH 6 Linux users, all developing their own applications. All were long-time Linux users, and two of them, one in travel services and one in financial services, had applications that can be described as both large and mission-critical.
The overall message is encouraging for Linux advocates, both the calm rational type as well as those who approach it with near-religious fervor. The latest releases from SUSE and Red Hat, both based on the 2.6.32 Linux kernel, show significant improvements in scalability and modest improvements in iso-configuration performance. One user reported that an application that previously had maxed out at 24 cores with SLES 10 was now nearing production certification with 48 cores under SLES 11. Performance scalability was reported as “not linear, but worth doing the upgrade.”
Overall memory scalability under Linux is still a question mark, since the widely available x86 platforms do not exceed 3 TB of memory, but initial reports from a user familiar with HP’s DL 980 verify that the new Linux Kernel can reliably manage at least 2TB of RAM under heavy load.
File system options continue to expand as well. The older Linux FS standard, ETX4, which can scale to “only” 16 TB, has been joined by additional options such as XFS (contributed by SGI), which has been implemented in several installations with file systems in excess of 100 TB, relieving a limitation that may have been more psychological than practical for most users.