about memory configuration

[c c]

HI,
    According to document we can setup memory size by
org.apache.ignite.configuration.DataStorageConfiguration.
But we do not know this works for off-heap or on-heap memory. We want to
know how to setup ignite jvm startup option(xms, xmx). Shoud jvm heap
memory be great than maxSixe in DataStorageConfiguration.  We know some hot
data would be deserialized from off-heap to on-heap. Would you mind giving
me some advice? thanks very much!