This is to do with how our clusters are setup and access the shared file system, and an advance topic.

When you’re on a login node/compute node you can list what is local to that machine - and in that respect, performing the following:

[@mblog1 ~]$ ls /
afs     apps  boot     dev  gscratch  install  lib64  misc  net  proc     root  sbin      srv  sys  usr  vast
alcova  bin   cluster  etc  home      lib      media  mnt   opt  project  run   software  SSH  tmp  var

You are listing what is from the / root local on this machine.

Remember: From the HPC cluster perspective, we are using a shared file system that can be accessed from all servers/nodes on that cluster.

If you perform a long form list, you can actually see that /home, /project and /gscratch are symbolic links (notice the l at the beginning of the permissions column) whose full paths are actually from /cluster/medicine/ from the perspective of the file system.

[salexan5@mblog1 ~]$ ls -l /
...
lrwxrwxrwx     1 root root    24 May 20 12:23 gscratch -> /cluster/medbow/gscratch
lrwxrwxrwx     1 root root    20 May 20 12:23 home -> /cluster/medbow/home
...
lrwxrwxrwx     1 root root    23 May 20 12:23 project -> /cluster/medbow/project
...

So, when we list the absolute paths for these various files we are returning their path with respect to the file system, not the local machine.