diff --git a/.DS_Store b/.DS_Store
deleted file mode 100644
index 4db263a..0000000
Binary files a/.DS_Store and /dev/null differ
diff --git a/.gitignore b/.gitignore
index f3b5f7c..ec9d7e1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,6 @@
+# Mac junk
+.DS_Store
+
 # Xcode
 #
 # gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
diff --git a/virtual/VirtualCommandRun.swift b/virtual/VirtualCommandRun.swift
index bb3b65e..8a1f46e 100644
--- a/virtual/VirtualCommandRun.swift
+++ b/virtual/VirtualCommandRun.swift
@@ -36,6 +36,10 @@ struct VirtualCommandRun: ParsableCommand {
   @Flag(name: .shortAndLong, help: "Enable NAT Networking")
   var network: Bool = false
 
+  // if not specified, will generate at random
+  @Option(name: [.customShort("a"), .long], help: "MAC Address")
+  var macaddr: String = ""
+
   @Flag(name: .long, help: "Show Version Information")
   var version: Bool = false
 
diff --git a/virtual/VirtualSystem.swift b/virtual/VirtualSystem.swift
index 059cb3d..1ede56d 100644
--- a/virtual/VirtualSystem.swift
+++ b/virtual/VirtualSystem.swift
@@ -40,7 +40,7 @@ class VirtualSystem: NSObject, VZVirtualMachineDelegate {
     var storage: [VZStorageDeviceConfiguration] = []
     if !command.disk.isEmpty {
       for disk in command.disk {
-        let blockAttachment = try VZDiskImageStorageDeviceAttachment(url: URL(fileURLWithPath: disk).absoluteURL, readOnly: true)
+        let blockAttachment = try VZDiskImageStorageDeviceAttachment(url: URL(fileURLWithPath: disk).absoluteURL, readOnly: false)
         let blockDevice = VZVirtioBlockDeviceConfiguration(attachment: blockAttachment)
         storage.append(blockDevice)
       }
@@ -50,6 +50,13 @@ class VirtualSystem: NSObject, VZVirtualMachineDelegate {
 
     if command.network {
       let networkDevice = VZVirtioNetworkDeviceConfiguration()
+      if !command.macaddr.isEmpty {
+        if let macAddress = VZMACAddress(string: command.macaddr) {
+            networkDevice.macAddress = macAddress
+        } else {
+            NSLog("Ignoring MAC Address: was not in acceptable format e.g. 01:23:45:ab:cd:ef")
+        }
+      }
       networkDevice.attachment = VZNATNetworkDeviceAttachment()
       network.append(networkDevice)
     }