(Illustration by Gaich Muramatsu)
Hello, I have thought about experiences of AFS and DFS deployment at our university since 1997, where I have been rather heavily involved, and my own experiences with Coda. I have not seen anything that would really need the separation between mount point name space and volume name space. Rather opposite is true, the arbitrary mapping between volumes and mount points creates confusion and even semantical inconsistency (in manuals for afs, dfs, coda you read "do not create multiple mount points for the same volume", that means we have not fully implemented the semantics and it works essentially by chance - there is nothing that can prevent creation of multiple mount points, in the general case). No functionality would be lost and a lot of problems avoided if hypothetical volume names would have to coincide with the mount point names. I mean - always. (given of course that there is a "rename" operation on volumes). Then maintainance of the system becomes a lot easier as you always know where a volume belongs. Otherwise the administrator *has* to maintain the mapping, and it must be simple to be manageable - but then it becomes a limitation - you cannot make complicated trees of mountpoints even when it is perfectly adequate for the particular application. Our dfs deployment project at the university had to develop special path-fileset mapping tools for that reason and still it is a burden to manage filesets. I know that Coda has inherited its internal structures from AFS but we have a chance to make changes. It would make the system more logical (hence more robust), more manageable and more appealing, just by getting rid of the arbitrary mountpoint-volume mapping. [Note that AFS has made a step from the traditional Unix "arbitrary mounts", /afs is always /afs not /we/mount/afs/here and it the Right thing. Now we have many more years of experience and have the possibility to make another step in similar direction.] To conclude, I'd welcome volume names that allowed any characters including '/', with length up to MAXPATHLEN (I mean "big enough", like 4 Kbyte, that would not cost a lot of space, typical volumes are much larger than 4K :-) (The volume name would not have to include the standard "/coda/" prefix, of course) Then mountpoints would not have to contain any information except "I'm a mountpoint". Some arguments to some commands would disappear, and mount point path and volume name could be used interchangeably. Hope you see the point. Note that I do not advocate a redesing - the concepts are proven and good. I advocate removing a hardly used feature that is - unnecessary, [a bit] dangerous, confusing and burdensome Best regards and thanks for the great software! -- IvanReceived on 2002-08-19 09:17:02