Hi Tony,

Excuse me for my late reaction but today i looked into this issue again with no success

1. VM [NOBAK] option and snapshot error in XO
   I added the [NOBAK] quotes to the name of the disk i want to skip the transfer for and fired a manual snapshot job. Almost instantly i get the same error as mentioned before, screenshot and error details below.

vm.snapshot
{
  "id": "b95f5a0e-3694-8066-ecb4-f72294d13f8a"
}
{
  "code": "UNIMPLEMENTED_IN_SM_BACKEND",
  "params": [
    "OpaqueRef:9bfbc055-40c4-44a0-ab1a-9f3bac6dc718"
  ],
  "task": {
    "uuid": "175c0c3f-d480-c769-31eb-423f8fe21aa9",
    "name_label": "Async.VM.snapshot",
    "name_description": "",
    "allowed_operations": [],
    "current_operations": {},
    "created": "20200923T14:40:20Z",
    "finished": "20200923T14:40:22Z",
    "status": "failure",
    "resident_on": "OpaqueRef:f03bc02e-9087-41f4-b0ac-c57f3f5220dd",
    "progress": 1,
    "type": "<none/>",
    "result": "",
    "error_info": [
      "UNIMPLEMENTED_IN_SM_BACKEND",
      "OpaqueRef:9bfbc055-40c4-44a0-ab1a-9f3bac6dc718"
    ],
    "other_config": {},
    "subtask_of": "OpaqueRef:NULL",
    "subtasks": [
      "OpaqueRef:c6ae9555-aec8-40ca-809a-4be54d852987"
    ],
    "backtrace": "(((process xapi)(filename ocaml/xapi/xapi_vm_clone.ml)(line 60))((process xapi)(filename list.ml)(line 106))((process xapi)(filename ocaml/xapi/xapi_vm_clone.ml)(line 94))((process xapi)(filename lib/xapi-stdext-pervasives/pervasiveext.ml)(line 24))((process xapi)(filename lib/xapi-stdext-pervasives/pervasiveext.ml)(line 35))((process xapi)(filename ocaml/xapi/xapi_vm_clone.ml)(line 102))((process xapi)(filename ocaml/xapi/xapi_vm_clone.ml)(line 136))((process xapi)(filename ocaml/xapi/xapi_vm_clone.ml)(line 162))((process xapi)(filename ocaml/xapi/xapi_vm_clone.ml)(line 168))((process xapi)(filename list.ml)(line 117))((process xapi)(filename ocaml/xapi/xapi_vm_clone.ml)(line 170))((process xapi)(filename ocaml/xapi/xapi_vm_clone.ml)(line 381))((process xapi)(filename lib/xapi-stdext-pervasives/pervasiveext.ml)(line 24))((process xapi)(filename lib/xapi-stdext-pervasives/pervasiveext.ml)(line 35))((process xapi)(filename ocaml/xapi/xapi_vm_snapshot.ml)(line 31))((process xapi)(filename ocaml/xapi/message_forwarding.ml)(line 100))((process xapi)(filename lib/xapi-stdext-pervasives/pervasiveext.ml)(line 24))((process xapi)(filename ocaml/xapi/rbac.ml)(line 236))((process xapi)(filename ocaml/xapi/server_helpers.ml)(line 83)))"
  },
  "message": "UNIMPLEMENTED_IN_SM_BACKEND(OpaqueRef:9bfbc055-40c4-44a0-ab1a-9f3bac6dc718)",
  "name": "XapiError",
  "stack": "XapiError: UNIMPLEMENTED_IN_SM_BACKEND(OpaqueRef:9bfbc055-40c4-44a0-ab1a-9f3bac6dc718)
    at Function.wrap (/opt/xo/xo-builds/xen-orchestra-202031082325/packages/xen-api/src/_XapiError.js:16:12)
    at _default (/opt/xo/xo-builds/xen-orchestra-202031082325/packages/xen-api/src/_getTaskResult.js:11:29)
    at Xapi._addRecordToCache (/opt/xo/xo-builds/xen-orchestra-202031082325/packages/xen-api/src/index.js:866:24)
    at forEach (/opt/xo/xo-builds/xen-orchestra-202031082325/packages/xen-api/src/index.js:887:14)
    at Array.forEach (<anonymous>)
    at Xapi._processEvents (/opt/xo/xo-builds/xen-orchestra-202031082325/packages/xen-api/src/index.js:877:12)
    at Xapi._watchEvents (/opt/xo/xo-builds/xen-orchestra-202031082325/packages/xen-api/src/index.js:1038:14)"
}

2. Installing guest tools on FreeBSB (FreeNAS)
   The xcp-ng documentation page describes that you will need to install 2 ports manually on FreeBSB. On following the instructions for let say sysutils/xe-guest-utilities on freshports[dot]org page it says to run the following commands:

To install the port: cd /usr/ports/sysutils/xen-guest-tools/ && make install clean
To add the package: pkg install xen-guest-tools

First command seems to fail on 'make' and second command i entered just to see what the output would be.

:SlapinFace: should have know that but didn't double check it.. anyways thanks!

Thank you @tony, based on your answer i now created delta backups with snapshot mode 'normal'. Tested the backup and restore with a couple of VMs Windows, Ubuntu and FreeBSB. With the windows and ubuntu VMs they where no issues. The FreeBSB with FreeNAS running throws an error: "UNIMPLEMENTED_IN_SM_BACKEND (OpaqueRef:9bfbc055-40c4-44a0-ab1a-9f3bac6dc718)".

Two things to note with the FreeBSB FreeNAS server:

1. There is second disk mounted, my data disk, to it. If possible can you exclude disks in a VM from a backup schedule?
2. There is no management tool installed on the VM. From my understanding freenas needs a different approach and before getting into that i want a backup.

After removing my physical nvidia graphics card and connecting the HMDI cable to my onboard adapter there is no video output. Looking in xcp-ng center -> host -> GPU i see "GPU configuration and monitoring is disabled, because there are no GPUs available on this host." and in XO shows blank/empty value.

(Homelab) Hardware:

• Motherboard: ASrock Fatality B450 (link)
• CPU: AMD Ryzen 7 2700X
• xcp-ng: 8.1.0
• xcp-ng center: 20.04.00
• xo-server: 5.66.0

lspci output:

[ ~]# lspci
00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Root Complex
00:01.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:01.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) PCIe GPP Bridge
00:01.3 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) PCIe GPP Bridge
00:02.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:03.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:04.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:07.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:07.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Internal PCIe GPP Bridge 0 to Bus B
00:08.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:08.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Internal PCIe GPP Bridge 0 to Bus B
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 59)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 51)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 0
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 1
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 2
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 3
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 4
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 5
00:18.6 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 6
00:18.7 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 7
01:00.0 Non-Volatile memory controller: Kingston Technology Company, Inc. Device 2263 (rev 03)
02:00.0 USB controller: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset USB 3.1 XHCI Controller (rev 01)
02:00.1 SATA controller: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset SATA Controller (rev 01)
02:00.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Bridge (rev 01)
03:00.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Port (rev 01)
03:01.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Port (rev 01)
03:04.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Port (rev 01)
03:05.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Port (rev 01)
03:06.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Port (rev 01)
03:07.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Port (rev 01)
05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06)
06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06)
08:00.0 SATA controller: ASMedia Technology Inc. ASM1062 Serial ATA Controller (rev 02)
09:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
0a:00.0 Non-Essential Instrumentation [1300]: Advanced Micro Devices, Inc. [AMD] Zeppelin/Raven/Raven2 PCIe Dummy Function
0a:00.2 Encryption controller: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Platform Security Processor
0a:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] USB 3.0 Host controller
0b:00.0 Non-Essential Instrumentation [1300]: Advanced Micro Devices, Inc. [AMD] Zeppelin/Renoir PCIe Dummy Function
0b:00.2 SATA controller: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] (rev 51)
0b:00.3 Audio device: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) HD Audio Controller

The isn't a very big issue because all of the management is done thru ssh, xcp-center or xo. But knowing i can't fallback on the possibility on managing the machine physically doesn't feel good. Is there a way in xcp to rescan its hardware, download or load the default onboard video drivers?

I recently migrated my homelab from VMware workstation to XCP-ng.
My homelab runs various servers on Windows and Linux like AD, Exchange, Nextcloud, FreeNAS and more.

On setting up a delta backup schedule i can choose in the settings -> advanced for snapshot mode and i wonder what is best practice for server like mentioned above.

Is it save to create delta backups of a exchange, database and others server with snapshot mode on 'normal' while in 'running' or 'halted' state or is it best practice to backup with snapshot mode 'with memory' or 'offline'.

So far i know shutting down the VM and then run a backup is the safest way. But i want to avoid that because of the dependencies of the servers on each other (LDAP, storage repositories and NFS shares linked to NAS, Reverse Proxy, etc)

Running:
XCP-ng: 8.1.0
XO-server: 5.66.0
XO-web: 5.69.0
All VMs have management agent installed