Improve performance on PFS machines at Subaru

The VMs seem to be very slow, probably from IO.
I'll compare installing conda on shell-ics to an NFS-mounted /software, to installing on a physical oldish machine with not special spinning disks. I'd expect the NFS to maybe cause some slowdown, but I though there was a fast cache for that on the server? But it is much worse than that – bad enough to be a problem.

bash Miniconda3-latest-Linux-x86_64.sh -b -p /software/conda: 2m22 vs. 13s
conda update -y conda: 1m5s vs. 16s
conda install numpy cython twisted ply future astropy ruamel_yaml ipython: 6m48s vs. 2m42s