I have to get used to XO. I always use XCP-ng Admin on Windows because old habits die hard, and there I cannot even select UEFI with all the Linux templates.

The magic that XO does is that it allows to use the templates, but with UEFI.

I have a VM that I've deployed with the "Other install media" option, so I just dettached the disk and reimported on the new one created by XO, with the correct template. Everything seems fine.

So my question about inheriting the template is not relevant if we use XO. Hope my understand is correct.

Thanks.

Yes I do see thats some settings when I ask for the profile using xe:

[15:19 xen1 ~]# xe template-param-list uuid=6c91b878-5095-421e-a914-224b3bb1088c 
uuid ( RO)                                  : 6c91b878-5095-421e-a914-224b3bb1088c
                            name-label ( RW): Red Hat Enterprise Linux 9
                      name-description ( RW): To use this template from the CLI, install your VM using vm-install, then set other-config-install-repository to the path to your network repository, e.g. http://<server>/<path> or nfs:server:/<path>
                          user-version ( RW): 1
                         is-a-template ( RW): true
                   is-default-template ( RW): true
                         is-a-snapshot ( RO): false
                           snapshot-of ( RO): <not in database>
                             snapshots ( RO): 
                         snapshot-time ( RO): 19700101T00:00:00Z
                         snapshot-info ( RO): 
                                parent ( RO): <not in database>
                              children ( RO): 
                     is-control-domain ( RO): false
                           power-state ( RO): halted
                         memory-actual ( RO): 0
                         memory-target ( RO): 0
                       memory-overhead ( RO): 36700160
                     memory-static-max ( RW): 4294967296
                    memory-dynamic-max ( RW): 4294967296
                    memory-dynamic-min ( RW): 4294967296
                     memory-static-min ( RW): 2147483648
                      suspend-VDI-uuid ( RW): <not in database>
                       suspend-SR-uuid ( RW): <not in database>
                          VCPUs-params (MRW): 
                             VCPUs-max ( RW): 1
                      VCPUs-at-startup ( RW): 1
                actions-after-shutdown ( RW): Destroy
                  actions-after-reboot ( RW): Restart
                   actions-after-crash ( RW): Restart
                         console-uuids (SRO): 
                                   hvm ( RO): false
                              platform (MRW): videoram: 8; hpet: true; secureboot: false; device-model: qemu-upstream-compat; apic: true; device_id: 0001; vga: std; nx: true; pae: true; viridian: false; acpi: 1
                    allowed-operations (SRO): changing_NVRAM; changing_dynamic_range; changing_shadow_memory; changing_static_range; provision; export; clone; copy
                    current-operations (SRO): 
                    blocked-operations (MRW): 
                   allowed-VBD-devices (SRO): 0; 1; 2; 3; 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): 0; 1; 2; 3; 4; 5; 6
                        possible-hosts ( RO): e49f21ab-723c-472e-8ad2-46c169e31172; 488e0f1d-69f3-4ecb-a37b-b5328764c229; f6d05b66-a21b-49bc-ad57-b4ca9bad756f
                           domain-type ( RW): hvm
                   current-domain-type ( RO): unspecified
                       HVM-boot-policy ( RW): BIOS order
                       HVM-boot-params (MRW): firmware: bios; order: cdn
                 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): 
                      last-boot-record ( RO): ''
                           resident-on ( RO): <not in database>
                              affinity ( RW): <not in database>
                          other-config (MRW): default_template: true; import_task: OpaqueRef:5bfca08c-951b-4024-a329-60260d8936fe; mac_seed: 99974ea1-478b-426d-b483-960e65912bd8; disks: <provision><disk bootable="true" device="0" size="10737418240" sr="" type="system"/></provision>; install-methods: cdrom,nfs,http,ftp; linux_template: true
                                dom-id ( RO): -1
                       recommendations ( RO): <restrictions><restriction field="memory-static-max" max="1649267441664"/><restriction field="vcpus-max" max="32"/><restriction field="has-vendor-device" value="false"/><restriction field="allow-gpu-passthrough" value="1"/><restriction field="allow-vgpu" value="1"/><restriction field="allow-network-sriov" value="1"/><restriction field="supports-bios" value="yes"/><restriction field="supports-uefi" value="no"/><restriction field="supports-secure-boot" value="no"/><restriction max="255" property="number-of-vbds"/><restriction max="7" property="number-of-vifs"/></restrictions>
                         xenstore-data (MRW): 
            ha-always-run ( RW) [DEPRECATED]: false
                   ha-restart-priority ( RW): 
                                 blobs ( RO): 
                            start-time ( RO): 19700101T00:00:00Z
                          install-time ( RO): 19700101T00:00:00Z
                          VCPUs-number ( RO): 0
                     VCPUs-utilisation (MRO): 
                            os-version (MRO): <not in database>
                    PV-drivers-version (MRO): <not in database>
    PV-drivers-up-to-date ( RO) [DEPRECATED]: <not in database>
                                memory (MRO): <not in database>
                                 disks (MRO): <not in database>
                                  VBDs (SRO): 
                              networks (MRO): <not in database>
                   PV-drivers-detected ( RO): <not in database>
                                 other (MRO): <not in database>
                                  live ( RO): <not in database>
            guest-metrics-last-updated ( RO): <not in database>
                   can-use-hotplug-vbd ( RO): <not in database>
                   can-use-hotplug-vif ( RO): <not in database>
              cooperative ( RO) [DEPRECATED]: true
                                  tags (SRW): 
                             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): 1
                         generation-id ( RO): 
             hardware-platform-version ( RO): 0
                     has-vendor-device ( RW): false
                       requires-reboot ( RO): false
                       reference-label ( RO): rhel-9
                          bios-strings (MRO): 

That's a lot of things.

The questions would be:

1. Is there a way to create another template that will inherit from the base template just to modify the UEFI support? Because let's be honest, it's 2024 and I don't feel like using legacy BIOS even for VMs... And when I mean inherit is that if something changes on the template it will be automatically changed on the inherited one. I'm aware that I can just clone/copy the template and modify but this will eventually lose updates to the base template.

2. Does XOA (the paid version) have more up to date templates with, for example, UEFI support for Linux? FreeBSD, etc?

Thank you all guys.

The Debian Bookworm 12 template contains: recommendations ( RO): <restriction field="supports-uefi" value="no"/>

This feature was added last month, and it appears to be using settings from the template to make this determination. Which template(s) are these VMs using? Can you show us the output of xe template-param-list uuid=<Template-UUID> where you replace <Template-UUID> with the actual UUID of one of the templates involved.

Regards,
Dan