http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=592

Summary: Para-virtualized Linux memory size cannot be successfully increased Product: Xen Version: unstable Platform: x86 OS/Version: Linux Status: NEW Severity: normal Priority: P2 Component: Guest-OS AssignedTo: xen-...@lists.xensource.com ReportedBy: john...@hp.com

If you start a para-virtualized Linux with "memory = 128" and "maxmem = 256" in the config file, if you do a "xm mem-set domain 256" later, Linux doesn't see the memory. It looks as if maxmem is never passed to the para-virtualized guest. If you add the "mem=256M" to the kernel command line, /proc/xen/balloon seems to indicate that it is ready to do the right thing ("Current allocation" and "Requested target" are both approximately 128M has approximately 128M on "Low-mem balloon "list), but when you try to do a "xm mem-set 256", the "Requested target" goes to 256M, but the "Xen hard limit" is hit and "Current allocation" is essentially unchanged.

Behavior on x86_64 is slightly different in that the "Low-free balloon" is zero even if the "mem=" keyword is specified.

All tests were on SuSE xen 3.0.2_09434-0.