1. Getting set up (7th-9th February, Leeds)¶
Warning
You MUST have PUMA, ARCHER2 and MOSRS accounts setup before starting this section.
Note
These instructions are for use on the UM Training Course held on 7-9th February 2023. If you are using them for self-study please contact NCAS-CMS for instructions.
1.1. Setup connection to PUMA & ARCHER2¶
To use the UM Introduction Tutorials you will first need to ensure you can connect from the local desktop to both PUMA & ARCHER2.
SSH key files¶
Before you try and connect to PUMA or ARCHER2, you need to make sure that you have the ssh-keys for both platforms available on the local desktop.
Hopefully you remembered to bring your ssh-keys with you on a USB stick. Please talk to a course tutor if you have forgotten them.
Copy your ssh-keys from the USB stick to the ~/.ssh directory.
Connecting via a Terminal (GNU/Linux & macOS)¶
Connect via a terminal with an X11 connection (XQuartz is also required when using macOS)
Login to PUMA:
ssh -Y -i ~/.ssh/id_rsa_puma <puma-username>@192.171.169.138
We suggest adding an entry to the ~/.ssh/config file so you don’t need to keep typing in the IP address. For example:
Host puma
Hostname 192.171.169.138
User <puma_username>
IdentityFile ~/.ssh/id_rsa_puma
ForwardX11 yes
ForwardX11Trusted yes
so that you can then connect using the command:
ssh puma
In a new terminal window, login to ARCHER2:
ssh -Y -i ~/.ssh/id_rsa_archer <archer2-username>@login.archer2.ac.uk
Again you could define a ~/.ssh/config file entry for each with the necessary information, if desired. For example:
Host login.archer2.ac.uk
User <archer2_username>
IdentityFile ~/.ssh/id_rsa_archer
ForwardX11 yes
ForwardX11Trusted yes
so that you could then just connect using the command:
ssh login.archer2.ac.uk
1.2. Set up your ARCHER2 environment¶
Login to ARCHER2 from your local desktop, copy the following profile to your home directory.
archer2$ cp /work/y07/shared/umshared/um-training/rose-profile ~/.profile
Change the permissions on your /home and /work directories to enable the NCAS-CMS team to help with any queries:
chmod -R g+rX /home/n02/n02/<your-username>
chmod -R g+rX /work/n02/n02/<your-username>
1.3. Set up your PUMA environment¶
Login to PUMA from your local desktop.
Configure ~/.profile¶
If this is the first time you have used your PUMA account, you will need to create a .profile. Copy our standard one:
puma$ cd
puma$ cp ~um/um-training/setup/.profile .
(If you already have a .profile, make sure it includes the lines from the standard file.)
Configure access to MOSRS¶
Run the mosrs-setup script which will take you through the set up process to access the Met Office Science Repository Service (Remember your MOSRS username is one word; usually firstnamelastname, all in lowercase):
puma$ ~um/um-training/mosrs-setup
Log out of PUMA and back in again (you will get a warning about not being able to find ~/.ssh/ssh-setup this can be ignored and will be resolved in the next step). You should first be prompted for your Met Office Science Repository Service password. Enter your password. Then you will be prompted for Username for ‘u’ - ‘https://code.metoffice.gov.uk/rosie/u’ . Enter your MOSRS username.
Note
The cached password is configured to expire after 12 hours. Simply run the command mosrs-cache-password to re-cache it if this happens. Also if you know you won’t need access to the repositories during a login session then just press return when asked for your MOSRS password.
Configure connection to ARCHER2¶
Due to ARCHER2 security and the UM workflow it is necessary to use a special ssh-key that allows submission of UM suite from PUMA.
Prior to the course you generated a UM workflow ssh-key called ~/.ssh/id_rsa_archerum.
i. Update ssh config file
In your PUMA ~/.ssh/config file add the following section:
Host login.archer2.ac.uk
User <archer2_username>
IdentityFile ~/.ssh/id_rsa_archerum
ForwardX11 no
ForwardX11Trusted no
Where <archer2_username> should be replaced with your ARCHER2 username. If you don’t have a ~/.ssh/config file create one.
ii. Set up ssh-agent
Setting up an ssh-agent allows caching of your id_rsa_archerum key passphrase for a period of time.
puma$ cp ~um/um-training/setup/ssh-setup ~/.ssh
Log out of PUMA and back in again to start up the ssh-agent process.
Add your id_rsa_archerum key to your ssh-agent by running:
puma$ ssh-add ~/.ssh/id_rsa_archerum
Enter passphrase for /home/<puma-username>/.ssh/id_rsa:
[TYPE_YOUR_PASSPHRASE]
Enter your passphrase when prompted. The ssh-agent will continue to run even when you log out of PUMA, however, it may stop from time to time, for example if PUMA is rebooted. For instructions on what to do in this situation see Restarting your ssh agent in the Appendix.
iii. Verify the setup is correct
Log in to ARCHER2 with:
puma$ ssh login.archer2.ac.uk
You should not be prompted for your passphrase. The response from ARCHER2 should be:
puma$ ssh login.archer2.ac.uk
PTY allocation request failed on channel 0
Comand rejected by policy. Not in authorised list
Connection to login.archer2.ac.uk closed.
Note
It is not possible to start an interactive login session on ARCHER2 from PUMA. For an interactive session you need to login from your local desktop.
You are now ready to try running a UM suite!