Hello, Discrete Mathematics Question; how did the samba developers conclude that the default mangling method "hash" results in a probability-of-name-clash of 1/1300? Please note, I am not looking for samba solutions here, just intensely curious on how this number was solved for. For instance, Q: What is considered the sample space of all possible file names here, were the "-" and "_" taken into account? Q: Are we considering all possible filename are equally likely to occur? Jeremy A, perhaps you know? Daniel
On Sun, Oct 29, 2006 at 11:35:22AM -0500, dkemper@intellisys-is.com wrote:> Hello, > > Discrete Mathematics Question; how did the samba developers conclude that the default mangling method "hash" results in a probability-of-name-clash of 1/1300? > > Please note, I am not looking for samba solutions here, just intensely curious on how this number was solved for. > > For instance, > > Q: What is considered the sample space of all possible file names here, were the "-" and "_" taken into account? > > Q: Are we considering all possible filename are equally likely to occur? > > Jeremy A, perhaps you know?Tridge did the original calculation, maybe he remembers. Jeremy.
Hello, Discrete Mathematics Question; how did the samba developers conclude that the default mangling method "hash" results in a probability-of-name-clash of 1/1300? Please note, I am not looking for samba solutions here, just intensely curious on how this number was solved for. For instance, Q: What is considered the sample space of all possible file names here, were the "-" and "_" taken into account? Q: Are we considering all possible filename are equally likely to occur? Jeremy A, perhaps you know? dotBomb daniel@dankemper.net
On Mon, Oct 30, 2006 at 12:18:00AM -0800, Jeremy Allison wrote:> On Sun, Oct 29, 2006 at 11:35:22AM -0500, dkemper@intellisys-is.com wrote: > > Hello, > > > > Discrete Mathematics Question; how did the samba developers conclude that the default mangling method "hash" results in a probability-of-name-clash of 1/1300?hash method is: ABCDEFGH.IJK | V ABCDE~xx.IJK xx is [A-Z0-9]. so 36*36 = 1296 (nearly equal 1300). -- --- Oota Toshiya --- oota at mail.linux.bs1.fc.nec.co.jp NEC Computers Software Operations Unit Shiba,Minato,Tokyo OSS Promotion Center Japan,Earth,Solar system (samba-jp Staff/postmaster,mutt-j admin,analog-jp postmaster)