@lmolina
of course i just downgraded again prior to this release... Sorry for the post. This was assisted with AI. I was also trying to do this while at work . I tried to verify this was not caused be my actions or configuration. If this is the results of upgrading and downgrading then everyelse use this a learning point.
[13:10 xcp-ng-disjqdnc ~]# yum history
Loaded plugins: fastestmirror
ID | Command line | Date and time | Action(s) | Altered
-------------------------------------------------------------------------------
16 | update --enablerepo=xcp- | 2026-10-27 13:04 | Update | 35 EE
15 | history undo 14 | 2026-10-27 10:37 | Downgrade | 35 EE
14 | update --enablerepo=xcp- | 2026-10-22 19:00 | Update | 35 EE
13 | update --disablerepo=* - | 2026-10-22 15:40 | Update | 1
12 | history undo 11 | 2026-10-22 13:37 | Downgrade | 35 EE
11 | update --enablerepo=xcp- | 2026-10-22 05:58 | Update | 35 EE
10 | update --disablerepo=* - | 2026-10-13 13:13 | Update | 6
9 | update --disablerepo=* - | 2026-10-05 15:04 | Update | 20
8 | update --enablerepo=xcp- | 2026-10-01 09:12 | Update | 45 EE
7 | update --disablerepo=* - | 2026-09-08 16:06 | Update | 6
6 | update --enablerepo=xcp- | 2026-08-26 08:39 | Update | 23 EE
5 | update --enablerepo=xcp- | 2026-08-14 13:23 | I, U | 53 EE
4 | update | 2026-07-28 10:46 | Update | 5
3 | update --enablerepo=xcp- | 2026-07-10 11:27 | Update | 23 EE
2 | install -y /root/twinsto | 2026-07-05 20:16 | Install | 12
1 | update --disablerepo=* - | 2026-07-05 01:56 | I, O, U | 138 EE
history list
updates installed no issues. I did a full backup job prior to new updates. after updates I did a delta backup. (vms are in VHD format)
migrated VMS back to QCOW2 and ran another backup. Because of migration this was a full backup..
@stormi @lmolina
Ran into a massive storage deadlock testing this batch of candidates on my NFS setups with Mellanox ConnectX links.
Here is the exact timeline and raw outputs of what went down:
Clean baseline: Rolled back previous stuff via yum history undo so the host was at a completely clean slate first.
Pre-test: Ran a full backup on standard VHD layout on the stable build. Zero issues, finished perfectly fine.
The update: Upgraded to the testing candidate repo (ID 16 in my history output above).
The trigger: Cleared a delta backup right after, then kicked off a full backup job. No other out-of-band tasks or live migrations were happening.
The Breakdown:
Mid-way through that full VHD backup, the entire storage layer completely locked up.
Toolstack went blind: xe task-list was completely blank. The host totally lost track of the job it was supposed to be running.
VMs deadlocked: Every user VM instantly frozen into a hard Blocked/Halted (B H) state. Trying a low-level xl destroy just turned them into permanent un-killable zombie domains (D P H).
[13:33 xcp-ng-rngyaiub ~]# xl destroy 1
[13:33 xcp-ng-rngyaiub ~]# list_domains
id | uuid | state
0 | 2083b5bd-7878-4598-960f-bb425814d338 | R
1 | 49f51614-c105-4fea-3103-566613ec79f2 | D P H
2 | dcbfaff1-d782-b42b-6eed-3d6b6d1ca032 | D P H
3 | 8cc17a78-ef65-1c06-4ac1-8e56b609d714 | D P H
4 | 2f724b50-5b16-9975-839b-fd85dd8ed065 | D P H
Hardware / Config Diagnostics:
Before pointing fingers at the candidate code, I checked if my Mellanox links or the network switch choked under the backup stream load. Ran ethtool immediately following recovery and the physical interfaces are pristine:
[14:16 xcp-ng-disjqdnc ~]# ethtool -S eth1 | grep -E "discard|drop|filter|error"
rx_xdp_drop: 0
tx_queue_dropped: 0
rx_oversize_pkts_sw_drop: 0
rx_pet_hdr_lookup_drop: 0
rx_pet_mdata_lookup_drop: 0
rx_xsk_xdp_drop: 0
rx_xsk_oversize_pkts_sw_drop: 0
rx_crc_errors_phy: 0
rx_in_range_len_errors_phy: 0
rx_discards_phy: 0
tx_discards_phy: 0
tx_errors_phy: 0
rx_prio0_discards: 0
rx_prio1_discards: 0
rx_prio2_discards: 0
rx_prio3_discards: 0
rx_prio4_discards: 0
rx_prio5_discards: 0
rx_prio6_discards: 0
rx_prio7_discards: 0
tx_pause_storm_error_events: 0
[14:18 xcp-ng-disjqdnc ~]# ethtool -k eth1 | grep -i vlan
rx-vlan-offload: on
tx-vlan-offload: on
rx-vlan-filter: on
vlan-challenged: off [fixed]
tx-vlan-stag-hw-insert: on
rx-vlan-stag-hw-parse: off [fixed]
rx-vlan-stag-filter: on [fixed]
Conclusion:
Network layout config problems, buffer overflows, or silent packet drops are 100% ruled out here (all hardware discards are flat zero).
This wasn't a user mistake or an accidental configuration mismatch. The new sm or blktap components hit a deep kernel lockup handling the multi-stream VHD storage exports. The file locks deadlocked the kernel handles so badly that the hosts ignored standard and low-level CLI commands entirely, forcing a hard out-of-band physical power cycle of the XCP-ng hosts and the TrueNAS storage server just to clear the uninterruptible I/O sleep queue.
I haven't touched a thing since getting the hardware back up and verifying what choked. The system is sitting exactly as it is right now. Let me know what specific debugging paths you want me to look at or what logs you need from that window to trace this down.
