From: Vladimir Pantelic <pan_at_nt.tu-darmstadt.de>
Date: Mon, 23 Sep 2002 08:27:18 +0200

Linus Nielsen Feltzing wrote:
> On Sat, 21 Sep 2002 16:29:11 +0200, Vladimir Pantelic wrote:
>
>>Linux could be much quicker though if it would use the information
>>in the FS_Info sector of FAT32 where the number of free clusters
>>and the last cluster allocated are stored. So Linux has to read tha
>>whole FAT to know how much free space there is on the drive.
>>The kernel sources say that Linux does ignore this information, I
>>have no idea why ?
>
>
> For what I know, the FS_Info is not guaranteed to be correct. So
> Linux doesn't bother, and always reads the while FAT. That approach
> works on fast drives, but slow USB drives suffer from it.

For what I have seen, Windows either does is correct or puts
0xFFFFFFFF = invalid into the free sectors and last allocated count.
Even if free sectors is not correct, the last allocated cluster is a
good hint to the next free space on the drive.

Regards,

Vladimir
Received on 2002-09-23