topic Re: Formating & mounting USB disk in Operating System - Linux

Formating & mounting USB disk

Oscar Garcia — Tue, 12 Oct 2010 15:10:53 GMT

Hi Guys,

I had a WesternDigital disk mounted as vfat in a SLES 10, but as I was using it to backup files, I had the inconvenient of all the files being saved as root.
Somewhere I found that if I formatted the disk as NTFS I would be able to assign permissions.
Well I formatted in an XP box, but now I can not mount it:
# mount /dev/sda /opt/backup
mount: /dev/sda: can't read superblock

More info:
# lsusb
Bus 005 Device 002: ID 03f0:1027 Hewlett-Packard
Bus 005 Device 003: ID 03f0:1327 Hewlett-Packard
Bus 005 Device 001: ID 0000:0000
Bus 006 Device 003: ID 1058:1003 Western Digital Technologies, Inc.
Bus 006 Device 001: ID 0000:0000
Bus 003 Device 001: ID 0000:0000
Bus 002 Device 001: ID 0000:0000
Bus 001 Device 001: ID 0000:0000
Bus 004 Device 001: ID 0000:0000

# fdisk -l
Disk /dev/dm-0: 5368 MB, 5368709120 bytes
255 heads, 63 sectors/track, 652 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/dm-0 doesn't contain a valid partition table
...
Disk /dev/dm-29: 16.1 GB, 16106127360 bytes
255 heads, 63 sectors/track, 1958 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/dm-29 doesn't contain a valid partition table

I will appreciate any help or advise you can give me.

Regards,

Re: Formating & mounting USB disk

Steven Schweda — Tue, 12 Oct 2010 15:39:30 GMT

> [...] but as I was using it to backup
> files, I had the inconvenient of all the
> files being saved as root.

"backup files" _how_, exactly?

> Somewhere

Where?

> I found that if I formatted the disk as
> NTFS I would be able to assign permissions.

Do you really believe that a UNIX(-like) file
system can't deal with file ownership and
permissions?

> Well I formatted in an XP box, but now I
> can not mount it:
> [...]

Have you considered telling "mount" that this
device has a NTFS file system on it?

man mount

Better yet, put the disk back the way it was,
and then try to solve your original problem
in some reasonable way.

Re: Formating & mounting USB disk

Steven Schweda — Tue, 12 Oct 2010 15:41:18 GMT

> [...] vfat [...]

OOPS. I missed that part. Sorry. The
"man mount" advice still holds, however.

Re: Formating & mounting USB disk

Oscar Garcia — Wed, 13 Oct 2010 09:30:15 GMT

Thanks Steve for your contributions.

I figured out what was wrong ( I was using /dev/sda1 rather than the new /dev/sdb1) and now I can mount the device formatted as NTFS, I think I panicked with all those errors that fdisk -l threw.

The entry in the fstab is

/dev/sdb1 /opt/backup ntfs rw,umask=0000 0 0

The problem now is that I can not write anything to it. For example:
# >hello
-bash: hello: Permission denied

and these are the permissions of the directory:
# ls -la /opt/backup
total 5
drwxrwxrwx 1 root root 4096 Oct 11 21:25 .
drwxr-xr-x 18 root root 496 Feb 23 2010 ..
drwxrwxrwx 1 root root 0 Oct 11 21:25 System Volume Information

Re: Formating & mounting USB disk

Oscar Garcia — Wed, 13 Oct 2010 14:36:55 GMT

Finally I managed to get it working! all thanks to cfdisk and fdisk (GUI interface). With #cfdisk /dev/sdb
I changed the type to linux and then using the partitioner (I believe is fdisk behind the YAST interface) I changed the type again to ext2 and formatted.
I think it mounted automatically after that, so unmounted changed the entry in fstab replacing ntfs with ext2, and re-mounted.
I can write, changed ownership, etc.

So we'll see how the backup goes...

Re: Formating & mounting USB disk

Steven Schweda — Wed, 13 Oct 2010 14:41:56 GMT

> The entry in the fstab is [...]

What does "mount" say about it?