diff --git a/api/src/org/apache/cloudstack/api/command/user/vm/DeployVMCmd.java b/api/src/org/apache/cloudstack/api/command/user/vm/DeployVMCmd.java
index 3d13d6bb209..f17c1c1fb38 100644
--- a/api/src/org/apache/cloudstack/api/command/user/vm/DeployVMCmd.java
+++ b/api/src/org/apache/cloudstack/api/command/user/vm/DeployVMCmd.java
@@ -121,7 +121,7 @@ public class DeployVMCmd extends BaseAsyncCreateCustomIdCmd {
 
     @Parameter(name = ApiConstants.ROOT_DISK_SIZE,
             type = CommandType.LONG,
-            description = "Optional field to resize root disk on deploy. Only applies to template-based deployments. Analogous to details[0].rootdisksize, which takes precedence over this parameter if both are provided",
+            description = "Optional field to resize root disk on deploy. Value is in GB. Only applies to template-based deployments. Analogous to details[0].rootdisksize, which takes precedence over this parameter if both are provided",
             since = "4.4")
     private Long rootdisksize;
 
diff --git a/engine/orchestration/src/org/apache/cloudstack/engine/orchestration/VolumeOrchestrator.java b/engine/orchestration/src/org/apache/cloudstack/engine/orchestration/VolumeOrchestrator.java
index 884da257cb7..d407bb1afff 100644
--- a/engine/orchestration/src/org/apache/cloudstack/engine/orchestration/VolumeOrchestrator.java
+++ b/engine/orchestration/src/org/apache/cloudstack/engine/orchestration/VolumeOrchestrator.java
@@ -599,9 +599,9 @@ public class VolumeOrchestrator extends ManagerBase implements VolumeOrchestrati
     @Override
     public boolean validateVolumeSizeRange(long size) {
         if (size < 0 || (size > 0 && size < (1024 * 1024 * 1024))) {
-            throw new InvalidParameterValueException("Please specify a size of at least 1 Gb.");
+            throw new InvalidParameterValueException("Please specify a size of at least 1 GB.");
         } else if (size > (MaxVolumeSize.value() * 1024 * 1024 * 1024)) {
-            throw new InvalidParameterValueException("volume size " + size + ", but the maximum size allowed is " + MaxVolumeSize + " Gb.");
+            throw new InvalidParameterValueException("volume size " + size + ", but the maximum size allowed is " + MaxVolumeSize + " GB.");
         }
 
         return true;
@@ -674,10 +674,10 @@ public class VolumeOrchestrator extends ManagerBase implements VolumeOrchestrati
         if (rootDisksize != null ) {
             rootDisksize = rootDisksize * 1024 * 1024 * 1024;
             if (rootDisksize > size) {
-                s_logger.debug("Using root disk size of " + rootDisksize + " for volume " + name);
+                s_logger.debug("Using root disk size of " + rootDisksize + " Bytes for volume " + name);
                 size = rootDisksize;
             } else {
-                s_logger.debug("Using root disk size of " + size + " for volume " + name + "since specified root disk size of " + rootDisksize + " is smaller than template");
+                s_logger.debug("Using root disk size of " + size + " Bytes for volume " + name + "since specified root disk size of " + rootDisksize + " Bytes is smaller than template");
             }
         }
 
diff --git a/server/src/com/cloud/vm/UserVmManagerImpl.java b/server/src/com/cloud/vm/UserVmManagerImpl.java
index 4b043a37c4a..a413d1131d6 100644
--- a/server/src/com/cloud/vm/UserVmManagerImpl.java
+++ b/server/src/com/cloud/vm/UserVmManagerImpl.java
@@ -3095,7 +3095,9 @@ public class UserVmManagerImpl extends ManagerBase implements UserVmManager, Vir
                     }
 
                     if ((rootDiskSize << 30) < templateVO.getSize()) {
-                        throw new InvalidParameterValueException("unsupported: rootdisksize override is smaller than template size " + templateVO.getSize());
+                        Long templateVOSizeGB = templateVO.getSize() / 1024 / 1024 / 1024;
+                        throw new InvalidParameterValueException("unsupported: rootdisksize override is smaller than template size " + templateVO.getSize()
+                            + "B (" + templateVOSizeGB + "GB)");
                     } else {
                         s_logger.debug("rootdisksize of " + (rootDiskSize << 30) + " was larger than template size of " + templateVO.getSize());
                     }