What year MBP is this? I tried running Ubuntu on Virtual Box on my mid 2014 MBP with 16GB ram, but that was anything but smooth. I ended up dual booting my T460s instead.
But perhaps the answer is VMware Fusion instead then.
I've only given Linux 6GB RAM at the moment, and it's working out fine. Currently running Ubuntu 19.10.
I picked VMware Fusion originally because it was reported to have good-ish support for GPU emulation that was compatible with Linux desktops at the time. Without it, graphics can be a bit clunky. With it, it feels smooth enough for me, as a desktop.
My browser is Firefox on the Mac side, but dev web servers all on the Linux side.
The VM networking is fine, but I use a separate "private" network (for dev networking) from the "NAT" network (outgoing connections from Linux to internet), so Wifi IP address changes in the latter don't disrupt active connections of the former.
My editor is Emacs GUI on the Mac side (so it integrates with the native Mac GUI - Cmd-CV cut and paste etc, better scrolling), although I can call up Emacs sessions from Linux easily, and for TypeScript, dev language servers etc., Emacs is able to run them remotely as appropriate.
Smoothness over SSH from iTerm is a different thing from graphical desktop smoothness.
When doing graphics work (e.g. Inkscape/GIMP/ImageMagick), or remote access to Windows servers using Remmina for VNC/RDP, I use the Linux desktop.
But mostly I do dev work in Linux over SSH from iTerm. I don't think I've ever noticed any smoothness issues with that, except when VMware networking crashes due to SMB/NFS loops that I shouldn't let happen :-)
Having your VM stored inside a file on a slow filesystem is bad. Having a separate lvm volume (on linux)/zvols (with zfs)/partition/disk is much more performant.
I store my Linux VM disk inside a file on a Mac filesystem (HFS+, the old one), and I haven't noticed any significant human-noticable I/O latency issues when using it. The Linux VM disk is formatted as ext4.
That's about human-scale experience, rather than measured latency. It won't be as fast as native, but it seems adequate for my use, even when grepping thousands of files, unpacking archives, etc, and I haven't noticed any significant stalling or pauses. It's encrypted too (by MacOS).
(That's in contrast to host-guest file access over the virtual network, which definitely has performance issues. But ext4 on the VM disk seems to work well.)
The VM is my main daily work "machine", and I'm a heavy user, so I'd notice if I/O latency was affecting use.
I'm sure it helps that the Mac has a fast SSD though.
(In contrast, on servers I use LVM a lot, in conjunction with MD-RAID and LUKS encryption.)
I've only given Linux 6GB RAM at the moment, and it's working out fine. Currently running Ubuntu 19.10.
I picked VMware Fusion originally because it was reported to have good-ish support for GPU emulation that was compatible with Linux desktops at the time. Without it, graphics can be a bit clunky. With it, it feels smooth enough for me, as a desktop.
My browser is Firefox on the Mac side, but dev web servers all on the Linux side.
The VM networking is fine, but I use a separate "private" network (for dev networking) from the "NAT" network (outgoing connections from Linux to internet), so Wifi IP address changes in the latter don't disrupt active connections of the former.
My editor is Emacs GUI on the Mac side (so it integrates with the native Mac GUI - Cmd-CV cut and paste etc, better scrolling), although I can call up Emacs sessions from Linux easily, and for TypeScript, dev language servers etc., Emacs is able to run them remotely as appropriate.
Smoothness over SSH from iTerm is a different thing from graphical desktop smoothness.
When doing graphics work (e.g. Inkscape/GIMP/ImageMagick), or remote access to Windows servers using Remmina for VNC/RDP, I use the Linux desktop.
But mostly I do dev work in Linux over SSH from iTerm. I don't think I've ever noticed any smoothness issues with that, except when VMware networking crashes due to SMB/NFS loops that I shouldn't let happen :-)