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--- unix:virtualization:techniques [2022/05/08 17:17] – rodolico
+++ unix:virtualization:techniques [2022/05/08 17:52] (current) – rodolico
@@ Line 26: / Line 26: @@
 ==== Live Migration ====
-Live Migration rapidly migrates a running vm from source to target, in many cases, with no downtime detectable by the end user.
+Live Migration rapidly migrates a running vm from source to target, in many cases with no downtime detectable by the end user.
-This generally has some limitations imposed, for example, migrating a running Xen machine must have Xen on both //source// and //target//, and the version of Xen must be very close on both machines. Same with KVM and virtlib. The CPU's on both machines should be similar also.
+This generally has some limitations imposed. For example, migrating a running Xen machine must have Xen on both //source// and //target//, and the version of Xen must be very close on both machines. Same with KVM and virtlib. The CPU's on both machines should be similar also.
-Limitations
+But, if you have compatible systems, you can migrate machines with little or no impact on end users, either as precursor to maintenance, or simply to manually load balance your hypervisors.
+=== Limitations ===
   * Both hypervisors must be running compatible hypervisors.
@@ Line 45: / Line 47: @@
   * //source// root user must have ssh access to //target//
     * It is preferred if //source//.root can log into //target//.root without password.
+=== Procedure ===
+  - Ensure root access from //source// to //target// (required for Xen, preferred for all others)
+    - **Xen** <code bash>ssh target 'ls'</code> should give you a listing of all files in /root on //target//
+    - **virtlib** issue the command <code bash>virsh -c qemu+ssh:%%//%%target/system list</code> should return a list of running virtuals on //target//
+  - Verify compatibility
+    - Ensure hypervisor compatibility between //source// and //target//
+    - Ensure network bridges with same name on //source// and //target//
+    - Ensure path to block devices same on //source// and //target//
+  - Issue command for migration from //source//. **Note** you can use the running virtual number instead of it's actual name in many cases
+    - **Xen** - <code bash>xl migrate vm targetmachine</code>
+    - **KVM** - unknown
+    - **virtlib** - <code bash>virsh migrate --live //vm// qemu+ssh://target/system</code>
 ===== Move VirtualBox images to KVM/Xen =====