Branden Sletteland wrote:
> I have also noticed this delay and have through instrumenting code
> have found that every block in the device gets read in.  I never
> checked if it was something in the df, filesystem, SCSI, or USB
> subsystems that was causing this.  I am usually doing df on USB
> storage devices formated as FAT 32 w/ and w/o LBA.
>
> Branden
>
>   
Thanks for your reply Branden. This explains why df would delay for a 
whole minute to terminate normally with a 500GB usb disk attached and 
only for a second or two with a 512MB usb stick attached. Btw both are vfat.

This brings another question though: Why read every single block during 
the first run of df after the partition is mounted? Obviously buffering 
500GB for fast access is currently out of the question so could it be 
the case that some sanity check was going on?

Regards,
Kostas

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