wip

@xen-orchestra/backups/ImportVmBackup.mjs

@@ -14,7 +14,26 @@ export class ImportVmBackup {
     this._xapi = xapi
   }
 
+  async #detectBaseVdis(){
+    const vmUuid = this._metadata.vm.uuid
+    const vm = await this._xapi.getRecordByUuid('VM', vmUuid)
+    const disks = vm.$getDisks()
+    const snapshots = {}
+    console.log({disks})
+    for (const disk of Object.values(disks)){
+      console.log({snapshots: disk.snapshots})
+      for(const snapshotRef of disk.snapshots){
+        
+        const snapshot = await this._xapi.getRecordByUuid('VDI', snapshotRef)
+        snapshots[snapshot.uuid] = disk.uuid
+      }
+    }
+    console.log({snapshots})
+    return snapshots
+  }
+
   async run() {
+    console.log('RUN')
     const adapter = this._adapter
     const metadata = this._metadata
     const isFull = metadata.mode === 'full'
@@ -22,18 +41,23 @@ export class ImportVmBackup {
     const sizeContainer = { size: 0 }
 
     let backup
+    
     if (isFull) {
       backup = await adapter.readFullVmBackup(metadata)
       watchStreamSize(backup, sizeContainer)
     } else {
+      console.log('restore delta')
       assert.strictEqual(metadata.mode, 'delta')
-
       const ignoredVdis = new Set(
         Object.entries(this._importIncrementalVmSettings.mapVdisSrs)
           .filter(([_, srUuid]) => srUuid === null)
           .map(([vdiUuid]) => vdiUuid)
       )
-      backup = await adapter.readIncrementalVmBackup(metadata, ignoredVdis)
+      //const vdiSnap = await this._xapi.getRecord('VDI-snapshot','83c96977-9bc5-483d-b816-4c96622fb5e6') 
+      //console.log({vdiSnap})
+      const baseVdis = this.#detectBaseVdis()
+      backup = await adapter.readIncrementalVmBackup(metadata, ignoredVdis, { baseVdis })
+      
       Object.values(backup.streams).forEach(stream => watchStreamSize(stream, sizeContainer))
     }
 
@@ -49,7 +73,7 @@ export class ImportVmBackup {
           ? await xapi.VM_import(backup, srRef)
           : await importIncrementalVm(backup, await xapi.getRecord('SR', srRef), {
               ...this._importIncrementalVmSettings,
-              detectBase: false,
+              baseVdis
             })
 
         await Promise.all([

@xen-orchestra/backups/RemoteAdapter.mjs

@@ -2,7 +2,7 @@ import { asyncEach } from '@vates/async-each'
 import { asyncMap, asyncMapSettled } from '@xen-orchestra/async-map'
 import { compose } from '@vates/compose'
 import { createLogger } from '@xen-orchestra/log'
-import { createVhdDirectoryFromStream, openVhd, VhdAbstract, VhdDirectory, VhdSynthetic } from 'vhd-lib'
+import { createVhdDirectoryFromStream, openVhd, VhdAbstract, VhdDirectory, VhdSynthetic ,Constants} from 'vhd-lib'
 import { decorateMethodsWith } from '@vates/decorate-with'
 import { deduped } from '@vates/disposable/deduped.js'
 import { dirname, join, resolve } from 'node:path'
@@ -694,8 +694,8 @@ export class RemoteAdapter {
     return container.size
   }
 
-  // open the  hierarchy of ancestors until we find a full one
-  async _createVhdStream(handler, path, { useChain }) {
+  // open the  hierarchy of ancestors until we find a usable one
+  async _createVhdStream(handler, path, { useChain, snapshotedVdis }) {
     const disposableSynthetic = useChain ? await VhdSynthetic.fromVhdChain(handler, path) : await openVhd(handler, path)
     // I don't want the vhds to be disposed on return
     // but only when the stream is done ( or failed )
@@ -713,7 +713,67 @@ export class RemoteAdapter {
     }
     const synthetic = disposableSynthetic.value
     await synthetic.readBlockAllocationTable()
-    const stream = await synthetic.stream()
+    let stream
+    // try to create a stream that will reuse any data already present on the host storage 
+    // by looking for an existing snapshot matching one of the vhd in the chain
+    // and transfer only the differential 
+    if (snapshotedVdis) {
+      try{
+
+        let vhdPaths = await handler.list(dirname(path), {filter: path=>path.endsWith('.vhd')})
+        stream = await Disposable.use(async function *(){
+          const vhdChilds = {}
+          const vhds = yield Disposable.all(vhdPaths.map(path => openVhd(handler, path, opts)))
+          for(const vhd of vhds){
+            vhdChilds[vhd.header.parentUuid] = vhdChilds[vhd.header.parentUuid] ?? []
+            vhdChilds[vhd.header.parentUuid].push(vhd)
+          } 
+  
+          let chain = []
+          let current = synthetic
+
+          // @todo : special case : we want to restore a vdi 
+          // that still have its snapshot => nothing to transfer
+
+          while(current != undefined){
+
+            // find the child VDI of path
+            const childs = vhdChilds[current.footer.uuid]
+  
+            //   more than one => break
+            //   inexistant => break
+            if(childs.length !== 1){
+              break
+            }
+            const child = childs[0]
+  
+            // not a differential => we won't have a list of block changed
+            // no need to continue looking
+            if(child.footer.diskType !== Constants.DISK_TYPES.DIFFERENCING){
+              break
+            }
+            // we have a snapshot
+            if(snapshotedVdis[current.footer.uuid] !== undefined){
+              const descendants = VhdSynthetic.open(handler)
+              negativeVhd = new NegativeVhd(synthetic, descendants)
+              return negative.stream()
+            } else {
+              // continue to look into the chain
+              // hoping we'll found a match deeper
+              current  = child 
+              chain.unshift(current)
+            }
+          }
+        })
+      }catch(error){
+        warn("error while trying to reuse a snapshot, fallback to legacy restore", {error})
+      }
+      
+    }
+    // fallback
+    if (stream === undefined) {
+      stream = await synthetic.stream()
+    }
 
     stream.on('end', disposeOnce)
     stream.on('close', disposeOnce)
@@ -721,7 +781,7 @@ export class RemoteAdapter {
     return stream
   }
 
-  async readIncrementalVmBackup(metadata, ignoredVdis, { useChain = true } = {}) {
+  async readIncrementalVmBackup(metadata, ignoredVdis, { useChain = true, snapshotedVdis } = {}) {
     const handler = this._handler
     const { vbds, vhds, vifs, vm, vmSnapshot } = metadata
     const dir = dirname(metadata._filename)
@@ -729,7 +789,7 @@ export class RemoteAdapter {
 
     const streams = {}
     await asyncMapSettled(Object.keys(vdis), async ref => {
-      streams[`${ref}.vhd`] = await this._createVhdStream(handler, join(dir, vhds[ref]), { useChain })
+      streams[`${ref}.vhd`] = await this._createVhdStream(handler, join(dir, vhds[ref]), { useChain, snapshotedVdis })
     })
 
     return {

@xen-orchestra/backups/_incrementalVm.mjs

@@ -143,11 +143,38 @@ export async function exportIncrementalVm(
   )
 }
 
+
+// @todo  movve this to incremental replication
+async function detectBaseVdis(vmRecord, sr) {
+  let baseVm
+  const xapi = sr.$xapi
+  const remoteBaseVmUuid = vmRecord.other_config[TAG_BASE_DELTA]
+  if (remoteBaseVmUuid) {
+    baseVm = find(
+      xapi.objects.all,
+      obj => (obj = obj.other_config) && obj[TAG_COPY_SRC] === remoteBaseVmUuid && obj[TAG_BACKUP_SR] === sr.$id
+    )
+
+    if (!baseVm) {
+      throw new Error(`could not find the base VM (copy of ${remoteBaseVmUuid})`)
+    }
+  }
+  const baseVdis = {}
+  baseVm &&
+    baseVm.$VBDs.forEach(vbd => {
+      const vdi = vbd.$VDI
+      if (vdi !== undefined) {
+        baseVdis[vdi.other_config[TAG_COPY_SRC]] = vbd.$VDI
+      }
+    })
+  return baseVdis
+}
+
 export const importIncrementalVm = defer(async function importIncrementalVm(
   $defer,
   incrementalVm,
   sr,
-  { cancelToken = CancelToken.none, detectBase = true, mapVdisSrs = {}, newMacAddresses = false } = {}
+  { baseVdis = {}, cancelToken = CancelToken.none, detectBase = true, mapVdisSrs = {}, newMacAddresses = false } = {}
 ) {
   const { version } = incrementalVm
   if (compareVersions(version, '1.0.0') < 0) {
@@ -157,35 +184,15 @@ export const importIncrementalVm = defer(async function importIncrementalVm(
   const vmRecord = incrementalVm.vm
   const xapi = sr.$xapi
 
-  let baseVm
-  if (detectBase) {
-    const remoteBaseVmUuid = vmRecord.other_config[TAG_BASE_DELTA]
-    if (remoteBaseVmUuid) {
-      baseVm = find(
-        xapi.objects.all,
-        obj => (obj = obj.other_config) && obj[TAG_COPY_SRC] === remoteBaseVmUuid && obj[TAG_BACKUP_SR] === sr.$id
-      )
-
-      if (!baseVm) {
-        throw new Error(`could not find the base VM (copy of ${remoteBaseVmUuid})`)
-      }
-    }
-  }
-
   const cache = new Map()
   const mapVdisSrRefs = {}
   for (const [vdiUuid, srUuid] of Object.entries(mapVdisSrs)) {
     mapVdisSrRefs[vdiUuid] = await resolveUuid(xapi, cache, srUuid, 'SR')
   }
 
-  const baseVdis = {}
-  baseVm &&
-    baseVm.$VBDs.forEach(vbd => {
-      const vdi = vbd.$VDI
-      if (vdi !== undefined) {
-        baseVdis[vbd.VDI] = vbd.$VDI
-      }
-    })
+  if (detectBase) {
+    baseVdis = await detectBaseVdis(vmRecord, sr)
+  }
   const vdiRecords = incrementalVm.vdis
 
   // 0. Create suspend_VDI
@@ -249,10 +256,11 @@ export const importIncrementalVm = defer(async function importIncrementalVm(
   await asyncMap(Object.keys(vdiRecords), async vdiRef => {
     const vdi = vdiRecords[vdiRef]
     let newVdi
-
+    // @todo how to rewrite this condition when giving directly a baseVdi  ?
     const remoteBaseVdiUuid = detectBase && vdi.other_config[TAG_BASE_DELTA]
     if (remoteBaseVdiUuid) {
-      const baseVdi = find(baseVdis, vdi => vdi.other_config[TAG_COPY_SRC] === remoteBaseVdiUuid)
+      const baseVdi = baseVdis[vdi.other_config[TAG_COPY_SRC]]
+      // @todo : should be an error only for detectBase
       if (!baseVdi) {
         throw new Error(`missing base VDI (copy of ${remoteBaseVdiUuid})`)
       }

packages/vhd-cli/commands/info.js

@@ -37,7 +37,7 @@ function mapProperties(object, mapping) {
 }
 
 async function showDetails(handler, path) {
-  const vhd = new VhdFile(handler, resolve(path))
+  const {value: vhd} = await openVhd(handler, resolve(path))
 
   try {
     await vhd.readHeaderAndFooter()