irtaza9

@poddingue thanks, In my case there is an update from Microsoft which destroy the RDP/Console. below is the link for it. I patched the fix and it's now working fine. Also I try to use proper template for windows based vms so that all the params gets in the guest by default.

https://support.microsoft.com/en-us/servicing/os/windows-server/2026/09/kb5129235-windows-server-2025-update

One of my window based vm gets stuck like no rdp/console below are the logs

Environment:

Host: XCP-ng (mtxen8)
Xen version: (please fill – run xl info | grep xen_version)
VM UUID: c3880bcc-9d46-1de6-e031-306894311cd2
Guest: Windows Server / Windows 10/11 (build 26100)
XCP-ng Windows Guest Tools: 9.2.350.0
Workload: PostgreSQL 18
Device-model: qemu-upstream-compat

Platform parameters (after fix):

viridian=true
viridian_time_ref_count=true
viridian_reference_tsc=true
viridian_stimer=true
viridian_apic_assist=true
viridian_crash_ctl=true
device-model=qemu-upstream-compat

Problem Description
The Windows VM periodically becomes completely unresponsive (both RDP and Xen console).

From the host the domain stays in permanent blocked state (-b----) and the QEMU device-model process disappears after receiving SIGTERM. The guest has to be force-destroyed and started again to recover.
This has happened multiple times (at least 4–5 unexpected shutdowns in the last 10 days).

Detailed Timeline of last occurrence (5 Oct 2026)

Time (approx),Event
3 Oct 07:25,Last clean PostgreSQL checkpoint
Several hours later,Guest becomes unresponsive
4 Oct 22:18:52,Windows Event 6008 – “previous system shutdown was unexpected”
4 Oct 22:18:55,Host log: qemu-dm-352: terminating on signal 15 from pid 1526469
After that,Domain remains registered but QEMU is gone → console + RDP dead
5 Oct ~10:22,Forced xe vm-shutdown force=true + clean start
After restart,"Everything works again (new domid, new QEMU process)"

xl list 352
# State: -b----   (permanently blocked)

ps aux | grep qemu-dm | grep 352
# → no process

# daemon.log
Oct  5 10:18:55 qemu-dm-352: terminating on signal 15 from pid 1526469

@poddingue I am facing a delay in PBD plug. I have a pool of 3 hosts, member hosts iscsi PBD is immediate but the master take so much time like 10,20 minutes. I want to make it fast. Also just to have info regarding pool master host, does master host perform any extra task as compared to member hosts which may cause the delay?

@poddingue

Yes multipath is enabled and we have two target ips. When I scan the target it calls the sr.probeIscsiIqns method and return the iqns in the dropdown as *(ip,ip) and on the select of *(ip,ip) it calls sr.probeIscsiLuns method. Both method take time to return the response. 90+ LUNs will be listed in the Lun dropdown after 4-5 minutes. Then On selection of LUN with respect to the id it calls sr.probeIscsiExists to validate the LUN, this method also take 1-3 minutes. After all this on create button click if then calls a method sr.createIscsi . This takes too much time too. I have a pool of 3 hosts and all servers have verified connectives to the SAN Storage. If you need any information regarding this, I will be happy to share.

The sr.probeIscsiIqns and sr.createIscsi is very slow. I checked the payload too and it send the target, which turned out to be a synthetic "*" (wildcard). Any way to optimize the SR.probe and creation?

@AtaxyaNetwork Hi, The default timeout for task is 24hrs. I initiated the copy process and it vanished out within 6-7hrs. How can I see the error or issue that is caused?

We are facing an issue observed multiple times when migrating assets from one server to another. We are using the copy functionality present in Orchestra to copy the VMs from one source to the other. While some have been successful, there have been cases in which the copy disappears during the later phases of it's execution without any error message or manual intervention.

In some cases, data is not completely copied from one place to the other. Can it please be highlighted if this is an issue with the feature or is there a limit cap placed on the amount of machines one can copy on the Servers or Orchestra.

@pdonias

But same template is allowing me to give the custom size to the existing VDI in v5 of XO.

Team,

I am facing issue while giving extra storage when i select any Installation source. But when i select storage then it allow me to give size.

XO info: Xen Orchestra, commit 91314

My Windows Server 2025 Standard VM randomly becomes completely unresponsive. No response via VNC console, RDP, or any network service. The VM shows as "Running" in XO/XCP-ng Center.
RAM/CPU graphs in XO freeze at the last value. No errors or relevant logs in Windows Event Viewer (daemon/kernel), XCP-ng host logs, or hypervisor logs. Only solution is a forced reboot (or power off/on via XO). After reboot, the VM works normally for hours/days until the next freeze.

This matches known Windows Server 2025 + Xen issues.

Environment

• Hypervisor: XCP-ng (version: please add yours, e.g. 8.3.x)
• Orchestrator: XO (XOA)
• VM Details (from XO API / XO):

{
  "id": "adf48a15-0b02-6fee-21d8-895190077680",
  "name_label": "<VM name>",
  "power_state": "Running",
  "virtualizationMode": "hvm",
  "os_version": {
    "name": "Microsoft Windows Server 2025 Standard",
    "uname": "10.0.26100"
  },
  "CPUs": { "max": 4, "number": 4 },
  "memory": { "size": 17179820032 },
  "viridian": true,
  "pvDriversVersion": "9.1.145-77",
  "pvDriversDetected": true,
  "managementAgentDetected": true,
  "management agent": "9.1.145-77",
  "NIC type": "Realtek RTL8139",
  "VGA": "cirrus",
  "boot": { "firmware": "bios", "order": "cd" },
  "other": {
    "base_template_name": "Other install media"
  }
}

• Hardware Virtualization: PVHVM with paravirtualization drivers enabled.
• Storage: (please specify: local SR, NFS, iSCSI, etc. + VBD types)
• Network: Realtek RTL8139 (emulated)

Steps Already Taken

• Viridian extensions are enabled (viridian: true).
• Latest XCP-ng Windows PV Drivers + Management Agent 9.1.145-77 installed.
• Windows Server 2025 is fully updated.
• Checked host logs (xl dmesg, journalctl), guest Event Viewer — nothing at the time of freeze.
• VM uses BIOS boot (not UEFI).

Additional Context

The freeze is completely random (no specific workload, time of day, or high load trigger observed).
Reboot always resolves it temporarily.
Similar reports exist for Windows 11 24H2 / Server 2025 on XCP-ng (Viridian synthetic timer, PV drivers, emulated devices).

Questions

Are there any known issues with Realtek RTL8139 NIC on Server 2025? Should I switch to a PV network driver / different emulated NIC?
Any recommendations on VGA (cirrus) or other VM settings?
Should I try forcing a kernel memory dump next time it hangs (xl trigger <domid> nmi)?
Any other diagnostics or logs I should collect?

Thanks in advance!