Messages in this thread |  | | From | David Lang <> | Date | Tue, 3 Sep 2002 22:23:35 -0700 (PDT) | Subject | Re: [RFC] mount flag "direct" (fwd) |
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On Wed, 4 Sep 2002, Daniel Phillips wrote:
> > You're well wide of the mark here, in that you're relying on the assumption > that caching is important to the application he has in mind. The raw transfer > bandwidth may well be sufficient, especially if it is unimpeded by being > funneled through a bottleneck like our vfs cache. >
the fact that he is saying that this needs to run normal filesystems tells us that.
if you need a filesystem to max out transfer rate and don't want to have it cache things that is a VERY specialized thing and not something that will match what NTFS/XFS/JFS/ReiserFS/ext2 etc are going to be used for.
either he has a very specialized need (in which case a specialized filesystem is probably the best bet anyway) or he is trying to support normal uses (in which case caching is important)
however the point is that the read-modify-write cycle is a form of cache, it is only safe if you aquire a lock at the beginning of it and release it at the end. A standard filesystem won't do this, this is what makes a DFS.
David Lang
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