Messages in this thread | | | Date | Tue, 30 Sep 2008 09:50:05 -0500 (CDT) | Subject | How can i read really 512 byte? | From | Milton Miller <> |
| |
On Tue, 30 Sep 2008 at 08:29:15 -0400 (EDT), Janos Haar wrote: > Now i am working on recover some data from one defective drive. I > am using dd_rescue, and dd, but both ready only 4K, i think, because > the kernel's block size is 4K. > > I have tried to google for the solution, but only found this trick: > > losetup /dev/loop0 /dev/hdc > blockdev --setbsz 512 /dev/hdc > > and after this set, trying to read the hdc... > > It looks like working on the first look, but not really. :-( The > 512 size bad sectors still have 4K sizes, but the reading attempt > takes more (8x ?) longer. > > Somebody can help me to set the reading block size to 512 byte?
You need to add O_DIRECT to the open call in the flags parameter (the second argument). (My brother tested this a year or so ago, and it worked for him).
milton
| |