# General UM tips

## CMS helpdesk

[new cms helpdesk website](https://cms-helpdesk.ncas.ac.uk/)

The [NCAS UM tutorial](http://cms.ncas.ac.uk/documents/training/November2019/)


## Check out a test suite

Suite `u-` should run on archer 2 with a swap of the charging code and user name

`Rosie go` search for suite and make a **copy**

`cd <suite-name>`
`rose edit`

make required edits user name and charging code and run  

## Running a Suite

in a suite dir run:

`rose suite-run --new`
`rose suite-run --restart`

## viewing a running suites

`rose sgc`

## Making ancils

### Xancil

seg faults:
`ulimit -Ss 40000`

## ncview
Cannot read xconv converted ancils. e.g. qrparam.orog.nc will only  be readable via xconv



### Gotchas

### Trouble shutting down a suite

```bash
ps -flu <username> | grep <suite-id>
```

then you can `kill -9 <PID>` the process that is still running preventing the suite from shutting down

# Debugging tips

if the job.err messages are completely unhelpful there's a number of things you can do.

1. Try running: `addr2line --exe=</path/too/executable> <address>`
2. Rerun in debug mode

in *site/<HOST_HPC>/suite-adds.rc* add
  ```bash
  module load atp
  export ATP_ENABLED=1
  ```
  to the `HOST_HPC init-script`

  **AND**

  switching on extra output by

  *um > env > runtime controls > atmosphere only* set PRINT_STATUS to "Extra diagnostic messages"

a similar thing can be done if your issue is in recon step

## Upgrading a suites

```bash
cd [your suite]
rose macro --fix
cd app/um
rose app-upgrade vn12.0 (or whatever)
cd …/fcm_make
```
<hr> 

## High Resolution Specific Notes

The Regional Area Science settings e.g. [RA2](https://code.metoffice.gov.uk/trac/rmed/wiki/ra2) are scale aware.

For sub-km simulations the RMED team have a useful [wiki page](https://code.metoffice.gov.uk/trac/rmed/wiki/subkm) of settings (time steps etc) and adjustments that may be needed.

<hr>

## Troubleshooting

### Ancillary generation issues

### VEGFRAC failing

Generating subkm vegfrac ancillaries might fail in their interpolating. Its unclear why this is but you can
use the fields from the parent nest where necessary. A neat way of doing this is to create exp1 config for
your failing nest.


 I’d just set the soil necessary ancillaries to `source=1` (allow recon to decide) for the failing nest's reconfiguration.
 This will then mean it picks up the parent nest ancillary data, which is more than good
 enough given the errors/approximations in the source data.

Assuming you are using the same science configuration for all resolutions you can copy
to that configuration to the expt1. i.e. copy `app/um/opt/rose-app-ra2t.conf` (or whatever config you’re using)
to `app/um/opt/rose-app-expt1.conf` .

Then add the ancil code from the `app/um/rose-app.conf` to the end of `expt1.conf` file,
 so for the latest version of the suite this is

```
[namelist:items(4c515841)]
ancilfilename='$UM_ANCIL_VEGFRAC_DIR/$UM_ANCIL_VEGFRAC_FILE'
domain=1
!!interval=1
l_ignore_ancil_grid_check=.true.
!!netcdf_varname='unset'
!!period=1
source=1
stash_req=216
update_anc=.false.
!!user_prog_ancil_stash_req=
!!user_prog_rconst=0.0

[namelist:items(884a098e)]
ancilfilename='$UM_ANCIL_SOIL_DIR/$UM_ANCIL_SOIL_FILE'
domain=1
!!interval=1
l_ignore_ancil_grid_check=.false.
!!netcdf_varname=10*'unset'
!!period=1
source=1
stash_req=40,41,43,44,46,47,48,207,220,223
update_anc=.false.
!!user_prog_ancil_stash_req=
!!user_prog_rconst=0.0
```

**NB `source=2` is edited to `source=1`**

Then in the affected resolution configuration window make sure your change the `ra2t` or whatever
in the drop down menu to `expt1`.

### Domain Size

At high Resolution you may find your domain size is larger than the max sizes check for in Defensive checks

You will need to checkout a copy of the source code and edit

`src/control/misc/atmos_max_sizes.F90`

*NB check the source you're checking out matches you might need a branch of a branch!*

Rebuild your executables and a larger domain will now be allowed