Brian Kernighan on the origins of Unix [LWN.net]

Brian Kernighan on the origins of Unix

Posted Jan 20, 2022 22:37 UTC (Thu) by ceplm (subscriber, #41334)
In reply to: Brian Kernighan on the origins of Unix by NYKevin
Parent article: Brian Kernighan on the origins of Unix

One thing which is very much not A Solved Problem™ is really working networked system. Something which would be networked but it would allow seamless work offline (or when the network is not that really fast as we would like it to be). We have either local systems (BTRFS, XFS, etc.) or network systems (NFS, Samba, etc.), but nothing in between.

I believe that Plan9 was more on the way towards this ideal, but Plan9 unfortunately died.

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Brian Kernighan on the origins of Unix

Posted Jan 20, 2022 22:44 UTC (Thu) by sfeam (subscriber, #2841) [Link] (11 responses)

We have either local systems (BTRFS, XFS, etc.) or network systems (NFS, Samba, etc.), but nothing in between.

Well, there were VAXClusters. Start a job on the cluster and it would migrate from machine to machine or node to node as they connected or disconnected themselves from the cluster. So far as I know unix/linux clusters never have reached this level of flexibility. Or maybe you were focusing specifically on filesystems?

Brian Kernighan on the origins of Unix

Posted Jan 21, 2022 11:16 UTC (Fri) by ceplm (subscriber, #41334) [Link] (3 responses)

Yes, VMSClusters look like something I was thinking about (as far as I can get from the Wikipedia article on it). I speak mostly out of my frustration with the current state of the affairs.

What I was thinking was that all my data are somewhere in The Cloud and whatever machine I use to access them (workstation, my hobby home laptop, tablet, or phone) I get access to the same data. Perhaps I don’t have all applications for all data (thinking that tablet or phone), then I cannot access those, but for those data which I have application for I can access the exact same data. And of course all that over the Internet, so fully secure, with authorizations and all that crap. And all that cached on the local disc, because otherwise latency will kill any user experience. It should be the normal state of everyday affairs not something like pulling your teeth slowly.

If you try something like that today you have NFS or Samba or stuff like that, which is unuseable for everyday work over even slightly non-local network (not mentioning a potential security disaster, so one switches to something even more obscure like sshfs and that’s even slower; NFSv4 may be more secure). Or you have some ultra-high-level stuff like Coda/OpenAFS etc. which requires really high-end hardware (no chance of running it on my tablet, phone could not be even mentioned) and even there I am not sure how well it works. Or you have series of mutually incompatible ad-hoc synchronization hacks (offline-IMAP, similar for CardDAV/CalDAV/etc., some weird in-browser proprietary caching for Google Docs, scripts using rsync, etc.).

http://ninetimes.cat-v.org/ seems to claim that Plan9 was supposed to be able of something like that, but I have my deepest doubts and I will believe it when I see it.

If you have some system which fulfils my requirements than you are either God or a liar, and I be on the latter.

Brian Kernighan on the origins of Unix

Posted Jan 21, 2022 23:54 UTC (Fri) by intgr (subscriber, #39733) [Link] (2 responses)

> What I was thinking was that all my data are somewhere in The Cloud and whatever machine I use to access them (workstation, my hobby home laptop, tablet, or phone) I get access to the same data.

Perkeep (previously Camlistore) is an attempt to solve this problem.

Brian Kernighan on the origins of Unix

Posted Jan 22, 2022 19:28 UTC (Sat) by ceplm (subscriber, #41334) [Link] (1 responses)

OK, an interesting idea I will try to learn more about it. Two problems seem obvious, why I think keeping it on the lower level of a filesystem makes more sense is that nobody wants to use any format they don’t already use (https://xkcd.com/743/), and the second is that I have never heard about, so I don’t expect it to take over the world anytime soon.

Brian Kernighan on the origins of Unix

Posted Jan 22, 2022 21:57 UTC (Sat) by ceplm (subscriber, #41334) [Link]

Hmm, I have to revert myself a bit. I was talking about completely independent system and then I was talking about using “normal” formats, which is mutually exclusive. Damn.

Concerning Perkeep, it looks interesting, but more as a secondary story for backup and archiving (something similar to https://github.com/ThinkUpLLC/ThinkUp ?) not as something where you actually work.

Brian Kernighan on the origins of Unix

Posted Jan 21, 2022 12:01 UTC (Fri) by Cyberax (✭ supporter ✭, #52523) [Link] (6 responses)

People tried that with Linux (famous Beowulf clusters!) but this really doesn't buy you a lot. Why would you migrate jobs between hosts in the first place?

You can do full machine migration easily either via VM checkpoint/restore or via CRIU, and this is useful in virtualization scenarios. You can also do high-availability via Xen where the same code runs on two computers at once, in case one of them goes down.

Brian Kernighan on the origins of Unix

Posted Jan 21, 2022 13:58 UTC (Fri) by malmedal (subscriber, #56172) [Link] (5 responses)

I don't think Beowulf clusters had that capability. You could schedule your job in any cluster-member, but not move them. Similarly with VMS, you could maintain the illusion of 100% uptime of a specially written application even while replacing all hardware.(admittedly I've only used VMS on VAX, maybe later versions could actually move jobs).

MOSIX however, could move arbitrary processes between cluster machines.

Another option is Condor, which uses CRIU to move simple processes.

Beowulf

Posted Jan 21, 2022 14:01 UTC (Fri) by corbet (editor, #1) [Link]

Yeah...Beowulf clusters still exist, they are just called "data centers" now...

Brian Kernighan on the origins of Unix

Posted Jan 21, 2022 18:14 UTC (Fri) by Cyberax (✭ supporter ✭, #52523) [Link] (3 responses)

Yes, they did. You could migrate processes between nodes: https://web.archive.org/web/20031002104248/http://www.ope... with some measure of automatic load balancing.

Brian Kernighan on the origins of Unix

Posted Jan 21, 2022 18:36 UTC (Fri) by malmedal (subscriber, #56172) [Link] (2 responses)

I believe I said Beowulf couldn't but MOSIX could migrate processes, they are different things.

Brian Kernighan on the origins of Unix

Posted Jan 21, 2022 18:38 UTC (Fri) by Cyberax (✭ supporter ✭, #52523) [Link] (1 responses)

Sorry, I'm a writer, not a reader. 🤦

Yes, of course you're correct. I used a Beowulf cluster with MOSIX back in the day, so that's why I'm confusing two of them.

Brian Kernighan on the origins of Unix

Posted Jan 22, 2022 13:03 UTC (Sat) by malmedal (subscriber, #56172) [Link]

My own memory also rather lacking at this point, but I think the deal-breaker for me was that the migrated process would die if the node it originally ran on rebooted.

Did MOSIX ever fix that issue?