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user66279
Asked: 2011-01-11 05:07:54 +0800 CST

Debian Squeeze and available memory (1GB absent)

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here I've a dedicated server with 12GB RAM and running Debian Lenny x64.

dmesg | grep Memory
[    0.004000] Memory: 11917152k/12259740k available (2279k kernel code, 333820k reserved, 1022k data, 216k init)

Since some days, I've another dedicated server (nearly same hardware), but with Debian Squeeze x64 (installed via debootstrap, Kernel 2.6.32-5-xen-amd64)

dmesg | grep Memory
[    1.551510] Memory: 6864620k/8151916k available (3146k kernel code, 1057736k absent, 229560k reserved, 1901k data, 600k init)

what does absent memory mean? And how can I get 1GB of RAM back?

debian memory lost

1 Answers

  1. Taken from Red Hat Bugzilla – Bug 598290:

    absent memory reflects the memory addressing space lost due to memory holes in the memory map. Typically holes are left for PCI space, IO, etc.. Every vendor model system is different, and every system will have a different value reported for the absent memory.

    Bottom line: It is not physical memory.

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