Not able to start Xen VM

Issue

• Getting the following error while trying to start a XEN VM:

# virsh start VM_name
error: Failed to start domain VM_name
error: POST operation failed: xend_post: error from xen daemon: (xend.err 'Error creating domain: I need 1048576 KiB, but dom0_min_mem is 262144 and shrinking to 262144 KiB would leave only 529240 KiB free.')