docs(backups/mirror): health check only applied on the last transferred

Fixes https://xcp-ng.org/forum/post/71769

@xen-orchestra/backups/_runners/_vmRunners/_AbstractRemote.mjs

@@ -22,6 +22,7 @@ export const AbstractRemote = class AbstractRemoteVmBackupRunner extends Abstrac
     this.config = config
     this.job = job
     this.remoteAdapters = remoteAdapters
+    this._settings = settings
     this.scheduleId = schedule.id
     this.timestamp = undefined
 

@xen-orchestra/backups/_runners/_writers/_MixinRemoteWriter.mjs

@@ -77,11 +77,11 @@ export const MixinRemoteWriter = (BaseClass = Object) =>
     healthCheck() {
       const sr = this._healthCheckSr
       assert.notStrictEqual(sr, undefined, 'SR should be defined before making a health check')
-      assert.notStrictEqual(
-        this._metadataFileName,
-        undefined,
-        'Metadata file name should be defined before making a health check'
-      )
+      if (this._metadataFileName === undefined) {
+        // this can happen when making a mirror backup with nothing to transfer
+        Task.info('no health check, since no backup have been transferred')
+        return
+      }
       return Task.run(
         {
           name: 'health check',

CHANGELOG.unreleased.md

@@ -9,6 +9,8 @@
 
 - Disable search engine indexing via a `robots.txt`
 - [Stats] Support format used by XAPI 23.31
+- [REST API] Export host [SMT](https://en.wikipedia.org/wiki/Simultaneous_multithreading) status at `/hosts/:id/smt` [Forum#71374](https://xcp-ng.org/forum/post/71374)
+- [Home & REST API] `$container` field of an halted VM now points to a host if a VDI is on a local storage [Forum#71769](https://xcp-ng.org/forum/post/71769)
 
 ### Bug fixes
 
@@ -17,6 +19,8 @@
 - [Settings/XO Config] Sort backups from newest to oldest
 - [Plugins/audit] Don't log `tag.getAllConfigured` calls
 - [Remotes] Correctly clear error when the remote is tested with success
+- [Backups/Full] Fix `Cannot read properties of undefined (reading 'healthCheckVmsWithTags')` (PR [#7396](https://github.com/vatesfr/xen-orchestra/pull/7396))
+- [Backups/Healthcheck] Don't run health checks after empty mirror backups (PR [#7396](https://github.com/vatesfr/xen-orchestra/pull/7396))
 
 ### Packages to release
 

docs/mirror_backup.md

@@ -10,7 +10,7 @@ Just go into your "Backup" view, and select Vm Mirror Backup.
 Then, select if you want to mirror incremental backups or full backups.
 You must have exactly one source remote, you must have one or more destinations. The mirroring speed will be limited by the slower remote.
 
-Most options of the full/incremental backups applies here, like concurrency (number of VM transferred in parallel), report, proxy and speed limit. You can also add a health check on schedules.
+Most options of the full/incremental backups applies here, like concurrency (number of VM transferred in parallel), report, proxy and speed limit. You can also add a health check on schedules. Please note that only the last transferred backup (if any) will be checked.
 
 :::tip
 If you have full and incremental backups on a remote, you must configure 2 mirror backup jobs, one full and one incremental.

packages/xo-server/src/xapi-object-to-xo.mjs

@@ -328,6 +328,34 @@ const TRANSFORMS = {
 
     const { creation } = xoData.extract(obj) ?? {}
 
+    let $container
+    if (obj.resident_on !== 'OpaqueRef:NULL') {
+      // resident_on is set when the VM is running (or paused or suspended on a host)
+      $container = link(obj, 'resident_on')
+    } else {
+      // if the VM is halted, the $container is the pool
+      $container = link(obj, 'pool')
+
+      // unless one of its VDI is on a non shared SR
+      //
+      // linked objects may not be there when this code run, and it will only be
+      // refreshed when the VM XAPI record change, this value is not guaranteed
+      // to be up-to-date, but it practice it appears to work fine thanks to
+      // `VBDs` and `current_operations` changing when a VDI is
+      // added/removed/migrated
+      for (const vbd of obj.$VBDs) {
+        const sr = vbd?.$VDI?.$SR
+        if (sr !== undefined && !sr.shared) {
+          const pbd = sr.$PBDs[0]
+          const hostId = pbd && link(pbd, 'host')
+          if (hostId !== undefined) {
+            $container = hostId
+            break
+          }
+        }
+      }
+    }
+
     const vm = {
       // type is redefined after for controllers/, templates &
       // snapshots.
@@ -422,8 +450,7 @@ const TRANSFORMS = {
       xenTools,
       ...getVmGuestToolsProps(obj),
 
-      // TODO: handle local VMs (`VM.get_possible_hosts()`).
-      $container: isRunning ? link(obj, 'resident_on') : link(obj, 'pool'),
+      $container,
       $VBDs: link(obj, 'VBDs'),
 
       // TODO: dedupe

packages/xo-server/src/xo-mixins/rest-api.mjs

@@ -253,6 +253,10 @@ export default class RestApi {
           const host = req.xapiObject
           res.json(await host.$xapi.listMissingPatches(host))
         },
+
+        async smt({ xapiObject }, res) {
+          res.json({ enabled: await xapiObject.$xapi.isHyperThreadingEnabled(xapiObject.$id) })
+        },
       }
 
       collections.pools.routes = {