On Tue, 2003-01-21 at 10:19, Turner, John wrote: > > Ugh. I hope not. I wonder why a motherboard would support 6 GB, then. > I've never worked with Linux with more than 2GB, so I've never run into this > issue before. Machines that have had 4 or 8 GB (or more) of RAM for me have > always been Solaris or AIX boxes. > > John
seems like I remember reading that there is a config option for 64GB of memory during kernel configuration.... yep. from the DOocumentation/Configure.help file in the source tree: High Memory support CONFIG_NOHIGHMEM Linux can use up to 64 Gigabytes of physical memory on x86 systems. However, the address space of 32-bit x86 processors is only 4 Gigabytes large. That means that, if you have a large amount of physical memory, not all of it can be "permanently mapped" by the kernel. The physical memory that's not permanently mapped is called "high memory". If you are compiling a kernel which will never run on a machine with more than 960 megabytes of total physical RAM, answer "off" here (default choice and suitable for most users). This will result in a "3GB/1GB" split: 3GB are mapped so that each process sees a 3GB virtual memory space and the remaining part of the 4GB virtual memory space is used by the kernel to permanently map as much physical memory as possible. If the machine has between 1 and 4 Gigabytes physical RAM, then answer "4GB" here. If more than 4 Gigabytes is used then answer "64GB" here. This selection turns Intel PAE (Physical Address Extension) mode on. PAE implements 3-level paging on IA32 processors. PAE is fully supported by Linux, PAE mode is implemented on all recent Intel processors (Pentium Pro and better). NOTE: If you say "64GB" here, then the kernel will not boot on CPUs that don't support PAE! The actual amount of total physical memory will either be auto detected or can be forced by using a kernel command line option such as "mem=256M". (Try "man bootparam" or see the documentation of your boot loader (grub, lilo or loadlin) about how to pass options to the kernel at boot time.) If unsure, say "off". My guess is that there is no precompiled binary kernel that sets this to 64GB since the number of folks that use it would be way limited. HTH Bret -- redhat-list mailing list unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/redhat-list
