About :: TODO :: Blog :: RSS :: Old blog :: Projects :: GIT :: Gallery :: Notes

Sun, 13 Jan 2008

POHMELFS filesystem development progress.

So far it is not that big - I'm still trying to setup 3 testing machines (I do not have physical access to them, so there should be a way to reboot them, check console output and so on), actually it is 3 small Xen domains on remote machine, so things are a bit more complex, but it is not enough for initial testing.

Since pohmelfs testing is postponed a bit I started distributed cache coherency system designing and hacking.
So far I will implement so called MESI protocol, which is used, for example, in IA-32 SMP machines. There is number of problems, since distributed system is vere different compared to bus-driven SMP machine, for example there is no way in remotely sane distributed system for single node to snoop data requests made by other nodes, but this trick is heavily used to catch requests for modified cache lines.
Cache coherency protocol is a very interesting problem itself, so I developing it first as a standalone application, which will be scalability tested against huge number of users. Then I will integrate it into pohmelfs.

I do not have fast internet at home anymore, I returned SkyLink modem and will use crappy GPRS until good internet connection setup, so this make things a bit more complex too...

Right now I have less time hacking things, since quite a lot of spare time is being eaten by some others, but I expect to be in shape soon.

So, if you do not see frequent update, its just a fluent time, things will be ok.
Stay tuned...

/devel/fs :: Link / Comments ()