[IBM z/VM] 'chmem -e' command gets fail with "Operation not permitted"

Issue

• chmem command fails to enable the standby memory in z/VM.
• It gets fail with write error: Operation not permitted

# chmem -e 0x00000002f0000000-0x00000002ffffffff
chmem: Memory Block 47 (0x00000002f0000000-0x00000002ffffffff) enable failed: Operation not permitted

# # echo 1 > /sys/devices/system/memory/memory44/online
-bash: echo: write error: Operation not permitted

# strace output
write(3, "online_movable", 14) = -1 EPERM (Operation not permitted)