Hi! > > >> It seems like the posix idea of unique <st_dev, st_ino> doesn't > > >> hold water for modern file systems > > > > > > are you really sure? > > > > Well Jan's example was of Coda that uses 128-bit internal file ids. > > > > > and if so, why don't we fix *THAT* instead > > > > Hmm, sometimes you can't fix the world, especially if the filesystem > > is exported over NFS and has a problem with fitting its file IDs uniquely > > into a 64-bit identifier. > > Note, it's pretty easy to fit _anything_ into a 64-bit identifier with > the use of a good hash function. The chance of an accidental > collision is infinitesimally small. For a set of > > 100 files: 0.00000000000003% > 1,000,000 files: 0.000003% I do not think we want to play with probability like this. I mean... imagine 4G files, 1KB each. That's 4TB disk space, not _completely_ unreasonable, and collision probability is going to be ~100% due to birthday paradox. You'll still want to back up your 4TB server... Pavel -- Thanks for all the (sleeping) penguins. - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
