I am fed up with XCP-ng, using default values, which are insane.. if VM is using 720MB, so I could lower ram to 768MB (or at least to 1GB, it is NOT feasible)[it must be set to 2GB]

@gtuminauskas Also, there is a setting for CentOS Stream 9 - 4GB ram - which is overkill 4x times WTF?

@nick-lloyd said in VM templates override:

Home -> Templates -> Find the template you want to change

No, it is not possible to do it [also, it is set not to 2GB, but to 4GB (wtf?)]

2gm ram probably would be OK if using GUI (desktop version) - but for minimal setup 2GB ram is simply overkill 2x times

When creating new CentOS Stream 9 (or Rocky9) VM, there is somewhere in the template set statically minimum RAM to 2GB.
I have no idea where these values are taken from, but to run VM in minimal installation, 1GB ram would be plenty and sufficient. Especially in home-lab or very limited environment this setting (coming from template) is not friendly at all (due to limited RAM available on the XCP-NG Host.

Would it be possible to override those templates?

For example, if I need to run simple nginx with few vhosts, for me it is just simply wasting of RAM (<800MB vs 2GB)
Basically choosing memory lower than 2GB gives an error in XCP-NG: MEMORY_CONSTRAINT_VIOLATION_ORDER()

vm.setAndRestart
{
  "memory": 1610612736,
  "id": "91f37e6e-d386-1dd5-c88d-b0245e2e4f1d",
  "force": false
}
{
  "code": "MEMORY_CONSTRAINT_VIOLATION_ORDER",
  "params": [],
  "call": {
    "method": "VM.set_memory_limits",
    "params": [
      "OpaqueRef:fe6860c3-3158-4728-9fdb-fbf84a57b701",
      2147483648,
      1610612736,
      1610612736,
      1610612736
    ]
  },
  "message": "MEMORY_CONSTRAINT_VIOLATION_ORDER()",
  "name": "XapiError",
  "stack": "XapiError: MEMORY_CONSTRAINT_VIOLATION_ORDER()
    at Function.wrap (file:///usr/local/lib/node_modules/xo-server/node_modules/xen-api/_XapiError.mjs:16:12)
    at file:///usr/local/lib/node_modules/xo-server/node_modules/xen-api/transports/json-rpc.mjs:38:21
    at runNextTicks (node:internal/process/task_queues:60:5)
    at processImmediate (node:internal/timers:447:9)
    at process.callbackTrampoline (node:internal/async_hooks:128:17)"
}