usb nbd for al exports

@vates/nbd-client/bench.mjs

@@ -0,0 +1,32 @@
+
+import NbdClient from "./index.mjs";
+
+
+
+async function bench(){
+    const client = new NbdClient({
+        address:'172.16.210.14',
+        port: 8077,
+        exportname: 'bench_export'
+    })
+    await client.connect()
+    console.log('connected', client.exportSize)
+
+    for(let chunk_size=16*1024; chunk_size < 16*1024*1024; chunk_size *=2){
+
+
+    let i=0
+    const start = + new Date()
+    for await(const block of client.readBlocks(chunk_size) ){
+        i++
+        if((i*chunk_size) % (16*1024*1024) ===0){
+                process.stdout.write('.')
+        }
+        if(i*chunk_size > 1024*1024*1024) break
+    }
+    console.log(chunk_size,Math.round( (i*chunk_size/1024/1024*1000)/ (new Date() - start)))
+
+    }
+}
+
+bench()

@vates/nbd-client/index.mjs

@@ -307,11 +307,11 @@ export default class NbdClient {
     })
   }
 
-  async *readBlocks(indexGenerator) {
+  async *readBlocks(indexGenerator = 2*1024*1024) {
     // default : read all blocks
-    if (indexGenerator === undefined) {
+    if (typeof indexGenerator === 'number') {
       const exportSize = this.#exportSize
-      const chunkSize = 2 * 1024 * 1024
+      const chunkSize =  indexGenerator
       indexGenerator = function* () {
         const nbBlocks = Math.ceil(Number(exportSize / BigInt(chunkSize)))
         for (let index = 0; BigInt(index) < nbBlocks; index++) {
@@ -319,6 +319,7 @@ export default class NbdClient {
         }
       }
     }
+
     const readAhead = []
     const readAheadMaxLength = this.#readAhead
     const makeReadBlockPromise = (index, size) => {

@xen-orchestra/xapi/vdi.mjs

@@ -64,8 +64,12 @@ class Vdi {
     })
   }
 
-  async _getNbdClient(ref) {
-    const nbdInfos = await this.call('VDI.get_nbd_info', ref)
+  async _getNbdClient(ref) { 
+    const nbdInfos = [{
+      address:'172.16.210.14',
+      port: 8077,
+      exportname: 'bench_export'
+  }]//await this.call('VDI.get_nbd_info', ref)
     if (nbdInfos.length > 0) {
       // a little bit of randomization to spread the load
       const nbdInfo = nbdInfos[Math.floor(Math.random() * nbdInfos.length)]
@@ -94,13 +98,15 @@ class Vdi {
 
       query.base = baseRef
     }
+
+    
     let nbdClient, stream
     try {
-      if (this._preferNbd) {
+      if (this._preferNbd || true) {
         nbdClient = await this._getNbdClient(ref)
       }
       // the raw nbd export does not need to peek ath the vhd source
-      if (nbdClient !== undefined && format === VDI_FORMAT_RAW) {
+      if (nbdClient !== undefined && format === VDI_FORMAT_RAW || true) {
         stream = createNbdRawStream(nbdClient)
       } else {
         // raw export without nbd or vhd exports needs a resource stream

packages/vhd-lib/createStreamNbd.js

@@ -15,7 +15,7 @@ const { fuHeader, checksumStruct } = require('./_structs')
 const assert = require('node:assert')
 
 exports.createNbdRawStream = async function createRawStream(nbdClient) {
-  const stream = Readable.from(nbdClient.readBlocks())
+  const stream = Readable.from(nbdClient.readBlocks(524288))
 
   stream.on('error', () => nbdClient.disconnect())
   stream.on('end', () => nbdClient.disconnect())