<![CDATA[Debian 9 virtual machine does not start in xcp-ng 8.3]]>Good afternoon, I just upgraded from xcp-ng 8.1 to 8.2 and then to 8.3. I have a virtual machine running Debian 9 that stopped working. It displays grub upon startup, but when it starts loading, it pauses and immediately shuts down. I downloaded the installer, and it does exactly the same thing. I tried older versions and it works fine. It seems to be related to the 4.9.0-11 kernel version. Do you know if this is a known issue?

Regards
Captura de pantalla 2025-08-01 155001.png Captura de pantalla 2025-08-01 155031.png

]]>https://xcp-ng.org/forum/topic/11126/debian-9-virtual-machine-does-not-start-in-xcp-ng-8.3RSS for NodeMon, 18 May 2026 00:49:36 GMTFri, 01 Aug 2025 19:05:59 GMT60<![CDATA[Reply to Debian 9 virtual machine does not start in xcp-ng 8.3 on Sat, 11 Oct 2025 02:17:57 GMT]]>I often wondered what's the general purpose of that option.
As I only have 1 - 2 socket servers, I always choose 1 socket with x cores (mostly 2 - 8, not exeeding 1 real CPU).
Also for historic reasons: Sockets have been limited, but not cores.

Does it generally make any difference on Xen side/backend?
VM OS might handle it different due to NUMA optimizations.

]]>https://xcp-ng.org/forum/post/98365https://xcp-ng.org/forum/post/98365Sat, 11 Oct 2025 02:17:57 GMT<![CDATA[Reply to Debian 9 virtual machine does not start in xcp-ng 8.3 on Mon, 08 Sep 2025 21:41:31 GMT]]>@mdavico said in Debian 9 virtual machine does not start in xcp-ng 8.3:

Update: If I change the vCPU configuration to 1 socket with 4 cores per socket the VM starts correctly

Interesring. First time I heard it had any effect at all on a VM.

]]>https://xcp-ng.org/forum/post/97130https://xcp-ng.org/forum/post/97130Mon, 08 Sep 2025 21:41:31 GMT<![CDATA[Reply to Debian 9 virtual machine does not start in xcp-ng 8.3 on Mon, 08 Sep 2025 04:11:34 GMT]]>@mdavico Thank you, now I can de-commission xcp 8.2! I was scratching my head on this one as well. Same deal, debian 9, imported vms from xcp 8.2 into a new 8.3 and then they did not boot.

]]>https://xcp-ng.org/forum/post/97125https://xcp-ng.org/forum/post/97125Mon, 08 Sep 2025 04:11:34 GMT<![CDATA[Reply to Debian 9 virtual machine does not start in xcp-ng 8.3 on Sat, 02 Aug 2025 09:42:04 GMT]]>OK so potentially a vCPU topology issue 🤔

]]>https://xcp-ng.org/forum/post/95924https://xcp-ng.org/forum/post/95924Sat, 02 Aug 2025 09:42:04 GMT<![CDATA[Reply to Debian 9 virtual machine does not start in xcp-ng 8.3 on Fri, 01 Aug 2025 20:30:26 GMT]]>Update: If I change the vCPU configuration to 1 socket with 4 cores per socket the VM starts correctly

]]>https://xcp-ng.org/forum/post/95912https://xcp-ng.org/forum/post/95912Fri, 01 Aug 2025 20:30:26 GMT<![CDATA[Reply to Debian 9 virtual machine does not start in xcp-ng 8.3 on Fri, 01 Aug 2025 20:13:57 GMT]]>How are you @olivierlambert ? He's at HVM.

uuid ( RO)                                  : 04f4eb58-97c6-b3c0-582d-96ebf841575e
                            name-label ( RW): PBX <(Test)
                      name-description ( RW):
                          user-version ( RW): 1
                         is-a-template ( RW): false
                   is-default-template ( RW): false
                         is-a-snapshot ( RO): false
                           snapshot-of ( RO): <not in database>
                             snapshots ( RO): 60dd299e-5627-5cae-927c-d371cf1cf858
                         snapshot-time ( RO): 19700101T00:00:00Z
                         snapshot-info ( RO):
                                parent ( RO): 60dd299e-5627-5cae-927c-d371cf1cf858
                              children ( RO):
                     is-control-domain ( RO): false
                           power-state ( RO): running
                         memory-actual ( RO): 1073737728
                         memory-target ( RO): 1073741824
                       memory-overhead ( RO): 14680064
                     memory-static-max ( RW): 1073741824
                    memory-dynamic-max ( RW): 1073741824
                    memory-dynamic-min ( RW): 1073741824
                     memory-static-min ( RW): 134217728
                      suspend-VDI-uuid ( RW): <not in database>
                       suspend-SR-uuid ( RW): <not in database>
                          VCPUs-params (MRW): weight: 256
                             VCPUs-max ( RW): 4
                      VCPUs-at-startup ( RW): 4
                actions-after-shutdown ( RW): Destroy
                  actions-after-reboot ( RW): Restart
                   actions-after-crash ( RW): Restart
                         console-uuids (SRO): 80f044cf-65b5-052a-69b2-83dfaf51e9bc
                                   hvm ( RO): true
                              platform (MRW): timeoffset: 0; device-model: qemu-upstream-compat; nx: true; acpi: 1; apic: true; pae: true; viridian: true; cores-per-socket: 1
                    allowed-operations (SRO): changing_dynamic_range; migrate_send; pool_migrate; changing_VCPUs_live; suspend; hard_reboot; hard_shutdown; clean_reboot; clean_shutdown; pause; checkpoint; snapshot
                    current-operations (SRO):
                    blocked-operations (MRW):
                   allowed-VBD-devices (SRO): 1; 2; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 50; 51; 52; 53; 54; 55; 56; 57; 58; 59; 60; 61; 62; 63; 64; 65; 66; 67; 68; 69; 70; 71; 72; 73; 74; 75; 76; 77; 78; 79; 80; 81; 82; 83; 84; 85; 86; 87; 88; 89; 90; 91; 92; 93; 94; 95; 96; 97; 98; 99; 100; 101; 102; 103; 104; 105; 106; 107; 108; 109; 110; 111; 112; 113; 114; 115; 116; 117; 118; 119; 120; 121; 122; 123; 124; 125; 126; 127; 128; 129; 130; 131; 132; 133; 134; 135; 136; 137; 138; 139; 140; 141; 142; 143; 144; 145; 146; 147; 148; 149; 150; 151; 152; 153; 154; 155; 156; 157; 158; 159; 160; 161; 162; 163; 164; 165; 166; 167; 168; 169; 170; 171; 172; 173; 174; 175; 176; 177; 178; 179; 180; 181; 182; 183; 184; 185; 186; 187; 188; 189; 190; 191; 192; 193; 194; 195; 196; 197; 198; 199; 200; 201; 202; 203; 204; 205; 206; 207; 208; 209; 210; 211; 212; 213; 214; 215; 216; 217; 218; 219; 220; 221; 222; 223; 224; 225; 226; 227; 228; 229; 230; 231; 232; 233; 234; 235; 236; 237; 238; 239; 240; 241; 242; 243; 244; 245; 246; 247; 248; 249; 250; 251; 252; 253; 254
                   allowed-VIF-devices (SRO): 1; 2; 3; 4; 5; 6
                        possible-hosts ( RO): 511b75ca-cea4-4831-9c13-4b81bf11f87a
                           domain-type ( RW): hvm
                   current-domain-type ( RO): hvm
                       HVM-boot-policy ( RW): BIOS order
                       HVM-boot-params (MRW): order: dc
                 HVM-shadow-multiplier ( RW): 1.000
                             PV-kernel ( RW):
                            PV-ramdisk ( RW):
                               PV-args ( RW):
                        PV-legacy-args ( RW):
                         PV-bootloader ( RW):
                    PV-bootloader-args ( RW):
                   last-boot-CPU-flags ( RO): vendor: GenuineIntel; features: 1fcbfbff-f7ba2223-2993fbff-00000403-00000001-00000281-00000000-00000000-00001000-9c000400-00000000-00000000-00000000-00000000-00000000
                      last-boot-record ( RO): ''
                           resident-on ( RO): 511b75ca-cea4-4831-9c13-4b81bf11f87a
                              affinity ( RW): <not in database>
                          other-config (MRW): auto_poweron: true; import_task: OpaqueRef:21e5bc93-aab0-4682-b6a4-3f7edb75e10f; mac_seed: b50c01ae-a763-6d83-f49a-08a6410ea93d; vgpu_pci: ; base_template_name: Other install media; install-methods: cdrom
                                dom-id ( RO): 26
                       recommendations ( RO): <restrictions><restriction field="memory-static-max" max="137438953472" /><restriction field="vcpus-max" max="16" /><restriction property="number-of-vbds" max="7" /><restriction property="number-of-vifs" max="7" /></restrictions>
                         xenstore-data (MRW): vm-data: ; vm-data/mmio-hole-size: 268435456
            ha-always-run ( RW) [DEPRECATED]: false
                   ha-restart-priority ( RW):
                                 blobs ( RO):
                            start-time ( RO): 20250730T03:35:37Z
                          install-time ( RO): 19700101T00:00:00Z
                          VCPUs-number ( RO): 4
                     VCPUs-utilisation (MRO): 0: 0.013; 1: 0.013; 2: 0.006; 3: 0.014
                            os-version (MRO): name: Debian GNU/Linux 9.11 (stretch); uname: 4.9.0-11-amd64; distro: debian; major: 9; minor: 11
                    PV-drivers-version (MRO): major: 8; minor: 0; micro: 50; build: 1
    PV-drivers-up-to-date ( RO) [DEPRECATED]: true
                                memory (MRO):
                                 disks (MRO):
                                  VBDs (SRO): c41f4f9a-fdf8-cb2a-e4d0-5e42e1eb7172; f008c7c2-26de-1261-2d24-6ee93f55107a
                              networks (MRO): 0/ipv6/0: fe80::f843:58ff:fe92:5993
                   PV-drivers-detected ( RO): true
                                 other (MRO): platform-feature-multiprocessor-suspend: 1; has-vendor-device: 0; feature-suspend: 1; feature-poweroff: 1; feature-reboot: 1; feature-vcpu-hotplug: 1; feature-balloon: 1
                                  live ( RO): true
            guest-metrics-last-updated ( RO): 20250730T03:36:23Z
                   can-use-hotplug-vbd ( RO): unspecified
                   can-use-hotplug-vif ( RO): unspecified
              cooperative ( RO) [DEPRECATED]: true
                                  tags (SRW): restored from backup
                             appliance ( RW): <not in database>
                     snapshot-schedule ( RW): <not in database>
                      is-vmss-snapshot ( RO): false
                           start-delay ( RW): 0
                        shutdown-delay ( RW): 0
                                 order ( RW): 0
                               version ( RO): 0
                         generation-id ( RO):
             hardware-platform-version ( RO): 0
                     has-vendor-device ( RW): false
                       requires-reboot ( RO): false
                       reference-label ( RO):
                          bios-strings (MRO): bios-vendor: Xen; bios-version: ; system-manufacturer: Xen; system-product-name: HVM domU; system-version: ; system-serial-number: ; baseboard-manufacturer: ; baseboard-product-name: ; baseboard-version: ; baseboard-serial-number: ; baseboard-asset-tag: ; baseboard-location-in-chassis: ; enclosure-asset-tag: ; hp-rombios: ; oem-1: Xen; oem-2: MS_VM_CERT/SHA1/bdbeb6e0a816d43fa6d3fe8aaef04c2bad9d3e3d
]]>https://xcp-ng.org/forum/post/95911https://xcp-ng.org/forum/post/95911Fri, 01 Aug 2025 20:13:57 GMT<![CDATA[Reply to Debian 9 virtual machine does not start in xcp-ng 8.3 on Fri, 01 Aug 2025 19:53:20 GMT]]>Hi,

Are you in PV or HVM mode?

]]>https://xcp-ng.org/forum/post/95909https://xcp-ng.org/forum/post/95909Fri, 01 Aug 2025 19:53:20 GMT