server: enable KVM volume and VM snapshot by default

server/src/main/java/com/cloud/configuration/Config.java

@@ -405,7 +405,6 @@ public enum Config {
             "300",
             "The time interval in seconds when the management server polls for snapshots to be scheduled.",
             null),
-    KVMSnapshotEnabled("Hidden", SnapshotManager.class, Boolean.class, "kvm.snapshot.enabled", "false", "Whether volume snapshot is enabled on running instances on a KVM host", null),
 
     // Advanced
     EventPurgeInterval(

server/src/main/java/com/cloud/server/ManagementServerImpl.java

@@ -789,6 +789,7 @@
 import com.cloud.storage.GuestOSVO;
 import com.cloud.storage.GuestOsCategory;
 import com.cloud.storage.ScopeType;
+import com.cloud.storage.snapshot.SnapshotManager;
 import com.cloud.storage.Storage;
 import com.cloud.storage.StorageManager;
 import com.cloud.storage.StoragePool;
@@ -4667,7 +4668,6 @@ public Map<String, Object> listCapabilities(final ListCapabilitiesCmd cmd) {
         final boolean isCallerAdmin = _accountService.isAdmin(caller.getId());
         boolean securityGroupsEnabled = false;
         boolean elasticLoadBalancerEnabled;
-        boolean KVMSnapshotEnabled;
         String supportELB = "false";
         final List<NetworkVO> networks = networkDao.listSecurityGroupEnabledNetworks();
         if (networks != null && !networks.isEmpty()) {
@@ -4684,7 +4684,7 @@ public Map<String, Object> listCapabilities(final ListCapabilitiesCmd cmd) {
 
         final long diskOffMinSize = VolumeOrchestrationService.CustomDiskOfferingMinSize.value();
         final long diskOffMaxSize = VolumeOrchestrationService.CustomDiskOfferingMaxSize.value();
-        KVMSnapshotEnabled = Boolean.parseBoolean(_configDao.getValue("KVM.snapshot.enabled"));
+        final boolean KVMSnapshotEnabled = SnapshotManager.KVMSnapshotEnabled.value();
 
         final boolean userPublicTemplateEnabled = TemplateManager.AllowPublicUserTemplates.valueIn(caller.getId());
 

server/src/main/java/com/cloud/storage/snapshot/SnapshotManager.java

@@ -53,7 +53,10 @@ public interface SnapshotManager extends Configurable {
     public static final ConfigKey<Integer> BackupRetryInterval = new ConfigKey<Integer>(Integer.class, "backup.retry.interval", "Advanced", "300",
             "Time in seconds between retries in backing up snapshot to secondary", false, ConfigKey.Scope.Global, null);
 
-    public static final ConfigKey<Boolean> VmStorageSnapshotKvm = new ConfigKey<>(Boolean.class, "kvm.vmstoragesnapshot.enabled", "Snapshots", "false", "For live snapshot of virtual machine instance on KVM hypervisor without memory. Requires qemu version 1.6+ (on NFS or Local file system) and qemu-guest-agent installed on guest VM", true, ConfigKey.Scope.Global, null);
+    public static final ConfigKey<Boolean> VmStorageSnapshotKvm = new ConfigKey<>(Boolean.class, "kvm.vmstoragesnapshot.enabled", "Snapshots", "true", "For live snapshot of virtual machine instance on KVM hypervisor without memory. Requires qemu version 1.6+ (on NFS or Local file system) and qemu-guest-agent installed on guest VM", true, ConfigKey.Scope.Global, null);
+
+    ConfigKey<Boolean> KVMSnapshotEnabled = new ConfigKey<>(Boolean.class, "kvm.snapshot.enabled", "Snapshots", "true", "Whether volume snapshot is enabled on running instances " +
+            "on a KVM hosts", false, ConfigKey.Scope.Global, null);
 
     ConfigKey<Boolean> kvmIncrementalSnapshot = new ConfigKey<>(Boolean.class, "kvm.incremental.snapshot", "Snapshots", "false", "Whether differential snapshots are enabled for" +
             " KVM or not. When this is enabled, all KVM snapshots will be incremental. Bear in mind that it will generate a new full snapshot when the snapshot chain reaches the limit defined in snapshot.delta.max.", true, ConfigKey.Scope.Cluster, null);

server/src/main/java/com/cloud/storage/snapshot/SnapshotManagerImpl.java

@@ -298,7 +298,7 @@ public String getConfigComponentName() {
     @Override
     public ConfigKey<?>[] getConfigKeys() {
         return new ConfigKey<?>[] {BackupRetryAttempts, BackupRetryInterval, SnapshotHourlyMax, SnapshotDailyMax, SnapshotMonthlyMax, SnapshotWeeklyMax, usageSnapshotSelection,
-                SnapshotInfo.BackupSnapshotAfterTakingSnapshot, VmStorageSnapshotKvm, kvmIncrementalSnapshot, snapshotDeltaMax, snapshotShowChainSize, UseStorageReplication};
+                SnapshotInfo.BackupSnapshotAfterTakingSnapshot, VmStorageSnapshotKvm, kvmIncrementalSnapshot, snapshotDeltaMax, snapshotShowChainSize, UseStorageReplication, KVMSnapshotEnabled};
     }
 
     @Override
@@ -1510,7 +1510,7 @@ private boolean hostSupportsSnapsthotForVolume(HostVO host, VolumeInfo volume, b
         if (vmId != null) {
             VMInstanceVO vm = _vmDao.findById(vmId);
             if (vm.getState() != VirtualMachine.State.Stopped && vm.getState() != VirtualMachine.State.Destroyed) {
-                boolean snapshotEnabled = Boolean.parseBoolean(_configDao.getValue("kvm.snapshot.enabled"));
+                boolean snapshotEnabled = KVMSnapshotEnabled.value();
                 if (!snapshotEnabled && !isFromVmSnapshot) {
                     logger.debug("Snapshot is not supported on host " + host + " for the volume " + volume + " attached to the vm " + vm);
                     return false;