[COFF] how was TCF different or similar to Mosix

[Charles H Sauer]

Amazon still carries the Popek/Walker LOCUS book 
https://smile.amazon.com/Distributed-System-Architecture-Computer-Systems/dp/0262517191/ 


I haven't cracked it open in years, but I assume it is still the best 
starting point.

On 4/2/2021 2:04 PM, Clem Cole wrote:
> On Fri, Apr 2, 2021 at 1:50 PM Theodore Ts'o <tytso at mit.edu 
> <mailto:tytso at mit.edu>> wrote:
> 
>     Out of curiousity, how was TCF different or similar to Mosix?
> 
> Many similar ideas.  TCF was basically the commercial implementation of 
> the Locus, which Jerry and students built at UCLA (one 11/70s 
> original).  I want to say the Locus papers are in some early SOSPs.
> 
> MOSIX was its own Unix-like OS, as was Locus [and some of this was in 
> Sprite too BTW].  TCF was a huge number of rewrites to BSD and was 
> UNIX.  The local/remote restructuring was ad-hoc.   By the time Roman 
> and I lead TNF, we had created a formal VPROC layer as an analog to the 
> VFS  layer (more in a minute). TNC was to be thegut of Intel's Paragon 
> using OSF/1 as base OS.
> 
> The basic idea of all of them is that the cluster is looks like a single 
> protection domain with nodes contributing resources.   A Larry says a ps 
> is cluster-wide.  TCF had the idea of features that each node provides 
> (ISA, floating-point unit, AP, /etc/..) so if a process needed specific 
> resources, it would only run on a node that had those resources.   But 
> it also meant that processes could be migrated from a node that had the 
> same resources.
> 
> One of the coolest demos I ever saw was we took a new unconfigured PS/2 
> at a trade show and connected the ethernet to it on the trade show 
> network, and put in a boot floppy. We dialed back into a system at an 
> LCC, and filled in some security things, details like the IP address of 
> the new system and soon it booted and joined the cluster.   It 
> immediately started to add services to the cluster, we walked away, and 
> (overnight) the system had set up the hard disk and started caching 
> locally things that were needed for speed.  Later I was editing a file 
> and from another screen migrated the process around the cluster while 
> the editing was active.
> 
> The problem with VPROC (like VFS) is it takes surgery all over the 
> kernel.   In fact, for Linux 2.x kernel the OpenSSI 
> <https://sourceforge.net/projects/ssic-linux/> folks did all the kernel 
> work to virtualize the concept of process, which sadly never got picked 
> up as the kernel.org <http://kernel.org> folks did not like it (a real 
> shame IMO).   BTW, one of the neat side effects of a layer like VPROC is 
> things like checkpoint/restart are free -- you are just migrating a 
> process to the storage instead of an active processor.
> 
> Anyway, Mosix has a lot of the same types of ideas.  I have much less 
> experience with it directly.
> 
> 
> 
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