On Sunday 30 June 2002 14:43, Jochen Voss wrote:
It seems, that the verify code uses the _old_ drive
parameters (either whatever was autodetected for media
that was in the drive before, set with setfdprm, or the
default) to verify the tracks, which are formatted with
the new parameters.
voss@automatix [~] superformat /dev/fd0 ds hd
This command results in a lot of I/O errors
and noises like the floppy drive is suffering.
The first few error messages are
I checked it out: the floppy parameters look correct; however there is
something else going on:
In recent kernels, the generic VFS's layer's read-ahead behavior has
changed. Now, the VFS attempts to read ahead on floppies, even if
BLKRA is set to 0.
In its default config, superformat alternatively formats a track, and
then immediately attempts to read from it (by using the system's read
syscall, rather than using raw floppy I/O). The problem is that then
the VFS decides to read ahead, and stumbles accross tracks which are
_not_yet_ formatted at that time, hence the scary noises.
Even when reformatting a disk as the same format, noises occur,
because reads and formatting now happen "in parallel", forcing the rw
head to move in an erratic pattern.
If I try the same with the "--verify_later"
everything works fine:
In today's patch, I made --verify_later the default.
In order to get the old behavior back, use --verify_later=0
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