[uClinux-dev] Jffs2 space problem

Friedrich, Lars lars.friedrich at wago.com
Mon Aug 8 06:33:35 EDT 2005


> > > > > /dev/rom4                  512       512         0 100% /
> > > > > /dev/ram0                  987         7       980   1% /var
> > > > > /dev/mtdblock5             512       512         0 100% /mnt
> > > > Hmm, probably not a good idea to erase the flash partition
> > > > while it is a mounted filesystem...
> > > my mounted filesystem is mtdblock4 and I'm erasing mtdblock5...
> > You mean the df command is lying?
> Yes, I expected to see Used =0 and Available = 512.

I expected that mtdblock5 is not mounted at all after the erase.

> > > One erased block has all byte 0xff ?
> > So one block was erased. 0xFF _is_ erased data in a flash device.
> After one partition is erased(all bytes to 0xff) is it
> formatted in some way or the "eraseall" command just erase it?

I assume with 'formatting' you mean copying the filesystem structure
onto it. No, eraseall does not force the user to use a specific filesystem.

> How does the "mount" command expect to find the erased 
> partition? All data to 0xff or something else?

mount doesn't care much about free space. Otherwise the system recognizes
free space according to the filesystem specifications. I recommend you
think about how you managed to mount mtdblock5 and execute df, if there is no
filesystem on it.

Best regards,
Lars Friedrich



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