Re: Filesystem fdisk and mount disagree

[Dom <toyer@rpdom.net>]

On 08/10/11 14:57, Mark Neidorff wrote:
> I'm not sure if everything is OK, or if I have to redo what I did.
>
> For backup I purchased a USB 3, 1.5 TB external drive.  (Using it USB 2 mode)
> The drive came formatted NTFS.  Not wanting to hassle with that, I reformatted
> it as EXT4.  That went fine, or so it seems.
>
> Now when I run fdisk, the partition still shows up as NTFS.
> Command (m for help): p
>
> Disk /dev/sdb: 1500.3 GB, 1500301910016 bytes
> 255 heads, 63 sectors/track, 182401 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disk identifier: 0x3e12cce7
>
>     Device Boot      Start         End      Blocks   Id  System
> /dev/sdb1               1      182401  1465136001    7  HPFS/NTFS
>
> ...but mount shows an ext4 filesystem:
>
> root@Mark:/tmp# mount
> /dev/sda2 on / type ext3 (rw,noatime)
> ....
> /dev/sdb1 on /media/339ca221-4ec1-45c2-9969-af0d8b5ffb0b type ext4
> (rw,nosuid,nodev,uhelper=udisks)
>
> So....should I fdisk the drive, delete what appears to fdisk to be an NTFS
> partition, create an ext4 and reformat it?  (I'm guessing that this is why I'm
> getting errors from my backup program)

Did you use fdisk (or similar) to change the partition type before 
reformatting? I'm guessing not.

The partition type values that fdisk sees are the one set by fdisk or 
another partitioning tool. The actual filesystem details depend on what 
you formatted it as. The two don't have to agree, but it's a good idea 
to keep them in sync.

Use fdisk and change the partition type. No need to delete/recreate the 
partition, or reformat it.

You don't say what errors you are getting from your backup program. 
Could you enlighten us please? Give examples of the errors and the name 
of the program you are using.

--
Dom