2 Replies Latest reply: Feb 10, 2013 12:43 PM by rukbat RSS

    Physical disk IO size smaller than fragment block filesystem size ?

      in one default UFS filesystem we have 8K block size (bsize) and 1K fragmentsize (fsize). At this scenary I thought all "FileSytem IO" will be 8K (or greater) but never smaller than the fragment size (1K). If a UFS fragment/blocksize is allwasy several ADJACENTS sectors on disk (in a disk with sector=512B), all "physical disk IO" it will allways, like "Filesystem IO", greater than 1K.

      But with dtrace script from DTrace Toolkit (bitesize.d) I can see IO with 512B size.

      ¿What is wrong in my assumptions or what is the explanation?

      Thank you very much in advance!!