IIRC, it depends on architecture and a compile-time kernel option. The smallest supported maximum value (e.g. a "lowest highest point", so to speak) that I know of for x86/x86_64 systems is 32 CPUs. Furthermore, I think that Linux treats each core as full-blown CPU, without caring how many specific cores on a single die (at least, it doens't care for these purposes, scheduling is a different matter...)
On RHEL5 boxes, I think the limits are 32 CPUs for 32bit systems, and 512 for 64bit systems.[1] However, you can tweak the CONFIG_NR_CPUS Kconfig option if you roll your own kernel, and the limit goes up to something around 4096 in later kernels. Linux should have no problems supporting the hardware originially mentioned (we routinly use CentOS on 32 core, 512GB RAM boxes). A more interesting question will be if cfservd and the IO system can make use of the rest of the hardware. :) [1] http://www.cyberciti.biz/tips/maximum-memory-and-cpu-limitations-for-linux-server.html On Fri, Apr 30, 2010 at 12:22:43PM -0400, Mark Burgess wrote: >I think the issue is where Linux can support this many cores. My understanding >was that >the Linux kernel was limited to 8 cores, but this is only hearsay. > >Paul Krizak wrote: >> Has anybody out there ever tried scaling up a cfengine server (v2.1 or >> v2.2) on a really big, fast server? I'm thinking on the order of 4 >> sockets, 24 cores, and a 10Gbit NIC. >> >> This is to support a particularly massive (and temporary) flood of >> cfagent requests to synchronize their local policy. It's going to be a >> lot easier to scale the server up in this case rather than adjust the >> policy to distribute requests to multiple cfservd's. >> >> So what's the experience out there? Can cfservd scale up and keep >> 10Gbit of bandwidth busy? Can it utilize 24 cores? Will it fall over >> or thrash on internal locks trying to run that many threads? >> > >-- >Mark Burgess > >------------------------------------------------- >Professor of Network and System Administration >Oslo University College, Norway > >Personal Web: http://www.iu.hio.no/~mark >Office Telf : +47 22453272 >------------------------------------------------- >_______________________________________________ >Help-cfengine mailing list >Help-cfengine@cfengine.org >https://cfengine.org/mailman/listinfo/help-cfengine -- Jesse Becker NHGRI Linux support (Digicon Contractor) _______________________________________________ Help-cfengine mailing list Help-cfengine@cfengine.org https://cfengine.org/mailman/listinfo/help-cfengine
