Embracing the command line: my unexpected career in computational biology.
The DAMTP system is described briefly in https://www.maths.cam.ac.uk/computing/newusers
There are about 500 linux machines in the DAMTP network. You can login to the ones in the 'public' group and to any research group that you belong.
https://mypassword.maths.cam.ac.uk/ use your raven password to get/set your maths password.
https://office.com New accounts should be on outlook.
64 core machine in DAMTP, with lots of RAM and disk space. Teaching machine. For the MPhil, this is the main (but not only) DAMTP machine I recommend you use.
Note that your home directory is shared across all DAMTP machines. Likewise, your password is the same across all DAMTP machines -- so if you change your password on one machine, it is effective for all machines.
From a terminal, type:
ssh sje30@subliminal.maths.cam.ac.uk # change to your CRSID
uname -a
If you have X windows you can instead do:
ssh -Y sje30@subliminal.maths.cam.ac.uk # change to your CRSID
xeyes
but installing X (on windows) is currently a pain.
A simpler way to get a remote graphical connection to subliminal is to use https://hotdesk.maths.cam.ac.uk
This allows you to run a persistent session on subliminal. You can close the browser tab and then come back to the same windows.
screen/tmux are similar programs for text-only terminals. These allow you to leave long jobs running and then reconnect later.
This allows you to run other COMPBIO software by extending your $PATH variable:
One time only you will need to run the following program to configure your logins:
/alt/applic/user-maint/sje30/COMPBIO/compbio_runmeonce.sh
Hint: hit TAB to complete filenames.
Logout and then log back in to subliminal for changes to take effect.
Check that you can now run R and other tools:
R
4*2
Ctrl-D to exit R. Then try rstudio:
rstudio
From a browser visit http://subliminal.maths.cam.ac.uk:8787/
As long as you have a browser, you can calculate...!
Warning: plots don't currently ([2023-10-04 Wed]) work; it has been reported but don't expect a quick update. The slow workaround:
pdf(file="~/test.pdf")
plot(1:10)
dev.off()
You can then open that file and the pdf will appear in a different browser tab. Refresh the browser tab if the file has changed to see an update.
quota
Bad news: not much quota, about 4 Gb, by default (although can ask for more).
Good news: home directory is backed up, about every 12 hours.
https://www.maths.cam.ac.uk/computing/storage/backups/mathsbackups
For working with large files. on subliminal you can store them in a 'data' directory (this is not backed up).
mkdir /local/data/mphilcompbio/2023/CRSID
Check permissions if you have anything private (e.g. coursework).
This disk (/local/data/mphilcompbio
) is about 15TB, and NOT backed-up.
Your files will be deleted in September 2024, so
please remove them before then.
Please check the local disk usage by examining
du -sh <directory>
df -h /local/data ## check storage as a whole.
There are also 'store' and 'scratch' data spaces that you might have access to:
https://www.maths.cam.ac.uk/computing/storage/storage
You can also store up to 1Tb of data (backed up) on onedrive.
man quota
quota -h ### -h is a 'switch' commonly used to show help
quota -s
ls
cat
less
which
nano / vi / emacs
cp
mv
mkdir
rm
pwd
cd
passwd
history
screen / tmux
Remote connections:
scp / ssh / rsync / unison
Managing processes:
who
uptime
top
htop
ps ux / kill
nice
For example, let's all run "slowjob" and then check the machine status using "top".
/alt/applic/user-maint/sje30/COMPBIO/bin/slowjob is the full path (remember to use TAB completion). Check what the file is.
https://help.uis.cam.ac.uk/service/wi-fi
https://help.uis.cam.ac.uk/service/network-services/remote-access/uis-vpn
ssh ssh.maths.cam.ac.uk
ssh linux.pwf.cam.ac.uk (??)
https://www.maths.cam.ac.uk/computing/remoteaccess/general
Should you keep your files on your laptop, or DAMTP?
DAMTP: files are backed up, but you don't get much quota. You might wish to use some service (github, unison) to keep certain directories in sync.
https://www.maths.cam.ac.uk/computing/remoteaccess/copyingfiles shows how to use tools like sftp
zendto is a service for securely sending/receiving large files, up to 20gb.
https://zendto.maths.cam.ac.uk/
https://www.maths.cam.ac.uk/computing/storage/nextcloud useful as a dropbox like solution. But limited quota, e.g. 1-2Gb.
If you have a mac laptop, then all you need is your 'Terminal' app and X11 and you should be ready.
If you have a windows machine, I recommend you install WSL2 and perhaps the X server (the latter is a bit fiddly). You can then start 'Windows Terminal'. Windows 11 should help a lot here, in that you won't need X11.
If you have a linux laptop, congratulations, no further edits needed.
Site licences for software like matlab, mathematica are available so that you can install these programs on your machine.
https://www.maths.cam.ac.uk/computing/software/maths
https://www.maths.cam.ac.uk/computing/queuing-system-desktops describes a queuing system available for long jobs in maths. (We will use slurm later.)
The Linux Command Line free book
Consider doing the half-day course offered by the Central UIS: Unix: Introduction to the Command Line Interface (not running during covid).
more recently, replaced by 'LiL: Unix essential training (online)' provided by LinkedIn. https://training.cam.ac.uk/ucs/event/3756056
I would also recommend Software Carpentry guides, e.g.
https://swcarpentry.github.io/shell-novice/
and perhaps, later: