On 01/20/2012 05:47 PM, Filipus Klutiero wrote: > Hi Pádraig and Jim, > > On 2012-01-20 09:15, Pádraig Brady wrote: >> On 01/20/2012 02:03 PM, Jim Meyering wrote: >>> Pádraig Brady wrote: >>> ... >>>>> As for %o, if you'd ask me what "I/O block size" means without any >>>>> context, I'm far from being sure I would answer it means size on >>>>> disk. I suggest to call this Size on disk, or Size used on the >>>>> filesystem. >>>> I/O implies transfer. >>>> So it corresponds to an "optimal transfer size hint" >>>> This value can be different at each layer, for example: >>>> >>>> $ stat -c "%o" . # file level >>>> $ stat -f -c "%s" . # file system level >>>> # blockdev --getioopt /dev/sda # device level >>>> >>>>> I'm not sure what language should be used instead. Perhaps instead >>>>> of blocks the manual should talk about "data storage device blocks". >>>> I suppose we could clarify "I/O block size" a bit. >>>> How about s|I/O block size|optimal I/O block transfer size| >>> or even without "block", >>> >>> "optimal I/O transfer size" >> OK I'll go with "optimal I/O transfer size hint", >> since there is nothing guaranteed about it, >> and in fact it's often wrong. >> >> cheers, >> Pádraig. >> > > I'm sorry but this change does not really address my concern.
It does actually, because... > The previous definition of %o did refer to "block" without specifying which > kind of block. This is no longer the case as the new definition no longer > refers to blocks. However, I still do not consider the new definition, > "Optimal I/O transfer size hint", understandable. > To come back to my original problem, I tried figuring out how much disk space > a small file took. In Windows, I would look at "Size on disk". If "optimal > I/O transfer size hint" means size on disk, this is still very unclear. Even > after reading your answers, I don't understand what "Optimal I/O transfer > size" means. > I am not looking for a transfer size. ... you know to ignore %o > My question is, if I'm putting a small file on my filesystem, how much space > will it use. > Here are 2 new descriptions I suggest: > Size occupied when including slack space > Size of the clusters occupied > > Appart from %o, the ambiguity problem in the descriptions of %b and %B > remains. No it does not. As I said they're abstract entities only valid in relation to each other. Just multiple %b x %B to get your answer. You may have missed the start of the last mail, where I said the du command is more appropriate (it does the above for you). cheers, Pádraig.
