Have posted the VMUFAT code to LKML – see here and similar.
It took me a while to work out how to do this, so I thought I should write it down for my own use and for anybody else who wants it.
I have my SSH daemon running on a non-standard port and wanted to push to my git repository.
The key is to add the repository, like so:
git remote add reponame ssh://username@server:port/repo/location/.git
Then pushing is as simple as:
git push reponame localbranch:remotebranch
The “string theory revolution” began in 1984 and I graduated with my astrophysics degree in 1987, perhaps unsurprisingly, having been taught nothing about it at all.
But now, reading The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos, (a good book) I discover that we may all be living on a brane – a three dimensional slab of reality “floating” inside ten dimensional space. And indeed there may be many of these branes perhaps just milimetres away from all of us, each of which might appear to its inhabitants (if its physical laws allow for any inhabitants, of course), as a fully dressed universe in its own right.
Now, so the theory goes, photons and indeed all particles of the electroweak or grand unified force (assuming it exists) cannot move between the branes, but gravitons, the theoretical (and undetected so far) quantum messengers of the gravitational force can. Indeed this ability of gravitons to stray into other dimensions is what is believed to make the gravitational force seem so weak to us.
But what if a highly massive object in another brane were to pass close by us. Such an object could have a very strong gravitational field that we would feel in this universe/brane and which could have drastic effects, perhaps putting us all at risk of “brane death”. Couldn’t it?
Well, I suspect I have misunderstood the mathematics of this. The fact we don’t see galaxies ripped to pieces by the super massive black holes at the centres of galaxies in other branes is rather more likely to lead me to believe that I have missed a point about how this works than to conclude the theory is that easily disproved.
Perhaps a reader might enlighten me?
- What happened before the Big Bang? [Ask A Physicist] (io9.com)
- The Hidden Reality (inertialframeofreference.wordpress.com)
- A Theory That Explains Why Earth’s Gravity Doesn’t Crush Us All [Astronomy] (io9.com)
- One in ten million neutrons could disappear into other universe and matter swapping between universes might be induced using lasers (nextbigfuture.com)
- How the Universe Came from Nothing (bigthink.com)
- Out There: Cosmologists Try to Explain a Universe Springing From Nothing (nytimes.com)
- Lee Smolin: Evolution Has A Better Chance (thebibleistheotherside.wordpress.com)
Obviously the whole world is waiting for VMUFAT to hit the streets, but it looks as though it will have to hold its collective breath a little longer, as I have hit more delays.
Working with big volumes (several megabytes) reveals the code eats a lot of memory in ways I don’t yet fully understand. But that will need to be fixed, even if no one is ever really likely to want a 32MB VMUFAT volume.
- Spoke too soon (of course) (cartesianproduct.wordpress.com)
It’s like the curse of the software demonstration: it doesn’t break until then.
I discovered as soon as I posted that I was ready to (try to) push the VMUFAT stuff up to main line that there was a bug in the software.
Very large VMUFAT volumes were not being properly handled. But I think I have fixed that now. Some more testing is due, though, before I proclaim victory a second time!
- VMUFAT: almost done (I hope) (cartesianproduct.wordpress.com)
A few attempts to get this in the kernel mainline then followed. It was a bruising experience and unsuccessful. But I am about to try again.
I am a bit more confident this time – not least because I have written some userland code which will allow anyone to test the filesystem out, whether they have a VMU or not: mkfs.vmufat is now available at GitHub – https://github.com/mcmenaminadrian/mkfs.vmufat/blob/master/mkfs.vmufat.c
Secondly I do think I am a better coder thanks to the MSc and have put some effort into fixing the filesystem code itself.
But we’ll see, hopefully tomorrow, how it goes down.
- One of those debugging nights (cartesianproduct.wordpress.com)
- Filesystem works (cartesianproduct.wordpress.com)
- Fan Made Sega Dreamcast Revival Has Me Wishing Sega Still Made Consoles (devicemag.com)
- Fedora puts back Btrfs deployment yet again (h-online.com)
- Maintenance of Linux kernel 2.6.32 is slowing down (h-online.com)