(Illustration by Gaich Muramatsu)
Jan Harkes wrote: > > and my idea, too (for example: venus decides at OPEN to access the > > remote file readonly but triggers the download into the cache in > > _parallel_. If download is complete it switches from remote to cached > > file). > > Venus will probably never support that kind of operation, our > versionvector/callback mechanism wouldn't even come close to handling > it reliably. Any consistency guarantees would be gone, and disconnected > operation would suffer big time. > > Imagine starting your XEmacs out of Coda, going home and trying to save > the document you were working on. However the code that happens to > handle saving has never been referenced before and xemacs segfaults. > > > And it would allow other projects to use the same interface, either > > using cached operations, direct operations or both. > > For direct operations, hack podfuk into a userspace nfs daemon. Does this really work in all cases ? Why does http://atrey.karlin.mff.cuni.cz/~pavel/podfuk/podfuk.html claim that NFS doesn't fit the needs ? And: AFAIK noone outside Sun has written a working NFSv3 server implementation yet (there are some NFSv2 server implementations out - but none of them look as they can be used to hook my work on...), all other vendors licensed Sun's code... ;-( I'm looking for something like this: glue kernel_vfs<------->userspace_vfs(midnight commander vfs/gnome vfs/etc.) Anyone seen something like this (e.g. the "glue") ? Forget performance problems for a few secs... I'm looking for a safe&portable way to hook-up new filesystems into a system. Writing kernel modules is not the right way - one mistake and the whole OS get'S killed. Bad. Ideas ? > And yes, > there will be many difficulties getting it right. The simplifications > that the Coda kernel module uses allow us to concentrate on what we do > best, while the filesystem that stores the container files and the VM > system handle the rest of the picture (synchronizing read/write/mmap > operations on the same pages, write/truncate race conditions etc.) And so on. This would cause all kinds of problems which already exists in systems like DFS or cachefs(Solaris). > Sorry, but I'm naturally negative of just about any block-level caching > proposals as far as Coda is concerned. The internal complexity of the > cache manager is already very high. Agreed... :-) ---- Bye, Roland -- __ . . __ (o.\ \/ /.o) Roland.Mainz_at_informatik.med.uni-giessen.de \__\/\/__/ gisburn_at_informatik.med.uni-giessen.de /O /==\ O\ MPEG specialist, C&&JAVA&&Sun&&Unix programmer (;O/ \/ \O;) TEL +49 641 99-13193 FAX +49 641 99-41359Received on 2000-10-17 16:25:16