Only 2GB of 4GB available Dell PowerEdge 860

This is not directly a cloudlmin problem but it appeared after rebooting with the xen kernel from a fresh install of Debian 5.0 amd64 and cloudmin pro. Any suggestions?

free total used free shared buffers cached Mem: 2538496 299684 2238812 0 7380 34328 -/+ buffers/cache: 257976 2280520 Swap: 9896000 0 9896000 uname -a Linux 2.6.26-1-xen-amd64 #1 SMP Fri Mar 13 21:39:38 UTC 2009 x86_64 GNU/Linux grub> displaymem displaymem EISA Memory BIOS Interface is present Address Map BIOS Interface is present Lower memory: 640K, Upper memory (to first chipset hole): 3072K [Address Range Descriptor entries immediately follow (values are 64-bit)] Usable RAM: Base Address: 0x0 X 4GB + 0x0, Length: 0x0 X 4GB + 0xa0000 bytes Reserved: Base Address: 0x0 X 4GB + 0xa0000, Length: 0x0 X 4GB + 0x60000 bytes Usable RAM: Base Address: 0x0 X 4GB + 0x100000, Length: 0x0 X 4GB + 0x300000 bytes
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Hmm... did you see all 4GB there when running "free" under a different kernel? I'd be curious to see what free looked like under the original Debian kernel you had been using.

What does your /boot/grub/menu.lst file contain?

Does it reserve any memory for the dom0 ?

default 0 timeout 5 color cyan/blue white/blue title Xen 3.2-1-amd64 / Debian GNU/Linux, kernel 2.6.26-1-xen-amd64 root (hd0,0) kernel /boot/xen-3.2-1-amd64.gz module /boot/vmlinuz-2.6.26-1-xen-amd64 root=/dev/sda1 ro console=tty0 module /boot/initrd.img-2.6.26-1-xen-amd64 title Debian GNU/Linux, kernel 2.6.26-2-amd64 root (hd0,0) kernel /boot/vmlinuz-2.6.26-2-amd64 root=/dev/sda1 ro quiet initrd /boot/initrd.img-2.6.26-2-amd64 title Debian GNU/Linux, kernel 2.6.26-2-amd64 (single-user mode) root (hd0,0) kernel /boot/vmlinuz-2.6.26-2-amd64 root=/dev/sda1 ro single initrd /boot/initrd.img-2.6.26-2-amd64 title Debian GNU/Linux, kernel 2.6.26-1-xen-amd64 root (hd0,0) kernel /boot/vmlinuz-2.6.26-1-xen-amd64 root=/dev/sda1 ro quiet initrd /boot/initrd.img-2.6.26-1-xen-amd64 title Debian GNU/Linux, kernel 2.6.26-1-xen-amd64 (single-user mode) root (hd0,0) kernel /boot/vmlinuz-2.6.26-1-xen-amd64 root=/dev/sda1 ro single initrd /boot/initrd.img-2.6.26-1-xen-amd64

Do you have any Xen instances running on the host when you run free ? Because I am pretty sure that memory allocated to Xen instances disappears from the total for the host systems..

You are correct.

If I use "xm top" instead of free or top I get the correct memory total. So everything is fine.

Would it make sense to calculate the memory differently or use a different label for the "Cloudmin Information" page where "Real Memory" shows the memory on dom0 not the actual "real" memory?

Maybe add a field for "Physical memory"?

If you check the "Edit System" page for a host system, in the "Detailed system status" section there should be a "Real memory for hosting" bar chart that takes Xen memory usage into account. This can differ quite a lot from the memory shown by the free command, as you can limit the dom0 (Xen host) to a fixed amount of memory via a kernel option.