Changed the InMemory bool to a uint32 so that it can be used to alter how much space to reserve

weed/storage/volume_create.go

@@ -8,7 +8,7 @@ import (
 	"github.com/joeslay/seaweedfs/weed/glog"
 )
 
-func createVolumeFile(fileName string, preallocate int64, useMemoryMap bool) (*os.File, error) {
+func createVolumeFile(fileName string, preallocate int64, useMemoryMap uint32) (*os.File, error) {
 	file, e = os.OpenFile(fileName, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
 	if preallocate > 0 {
 		glog.V(0).Infof("Preallocated disk space for %s is not supported", fileName)