# dmsg
[335773.344080] xen:balloon: Cannot add additional memory (-17)
[335805.413385] xen:balloon: Cannot add additional memory (-17)
[335837.536078] xen:balloon: Cannot add additional memory (-17)
 
# cat /sys/devices/system/xen_memory/xen_memory0/info/current_kb > /sys/devices/system/xen_memory/xen_memory0/target_kb