[Samba] extending files slow on FAT filesystems

[Mattias Rönnblom]

Hi,

I'm running Samba 3.0.23a on Linux. One of my share is a USB disk with
a FAT32 filesystem.

When copying large files from my Windows XP machine to this share,
smbd seem to "reserve" (by using ftruncate()) the space needed on the
USB disk before actually doing any copying. This ftruncate() operation
takes quite a while when the file is large. It may even cause the
client to time out.

If I reformat the disk with ext2, ftruncate() runs fast.

Is there some way of turning off this "pre-allocation" behaviour? I've
consulted smb.conf(5), but I've been unable to find anything of use.

Would you consider this a problem in Samba or in the VFAT filesystem
driver?

Regards,
        Mattias