KB2010010701: Memory assignment for vservers with Linux kernel 2.6.18 and older

Please note:

Vserver using Linux kernel version 2.6.18 or older are not able to use more memory than assigned at boot time. To work around that problem provide the booting kernel with the option mem=maximum_memory. Therefore edit the Xen DomU config and add to following option:

extra="... mem=4096M"

With 64 bit vservers you can use higher values. Now you can start up the vserver with e.g. 256 MB and assign memory up to the value set in the option later.

With vservers with newer kernels that problem does not occur.