Re: [LUG] Formatting external drives etc

[Gordon Henderson <gordon+dcglug@xxxxxxxxxx>]

On Sat, 9 Apr 2011, Neil Winchurst wrote:

> Rob Beard wrote:
> > On 08/04/11 17:45, Neil Winchurst wrote:
> > > I have a USB memory stick and may one day need an external hard drive.
> > > When bought how will they be formatted? And if I would like them to be
> > > formatted to eg EXT4 what would be the best utility to use?
> > >
> > > Thanks for any help
> > >
> > > Neil
> >
> > They will most likely be formatted to FAT32.
> >
> > Personally I tend to leave my USB sticks in FAT32 format, that way I can
> > transfer them between my notebook, my XBOX360, PS3 and the wifes's PC.
> Two points. All the computers at home are Linux so I have no need of Windows 
> at all. Secondly, I thought that with FAT32 you lose permissions. Is that 
> correct?

Yes. And there are issues with long filenames too...

> > If I do format anything though (my external USB hard drive is EXT4
> > format) I use mkfs.ext4 in the command line.
> >
> > I also tend to change the partition type from 6 (or b or c I believe)
> > which are Windows types to type 83 which is set to Linux.
> I must have a look at this, which is new to me. Wouldn't formatting to say 
> EXT4 automatically change the partition type too?

No. Well - Not the standard command-line mkfs command, anyway. Who knows 
what a graphical tool will do for you.

The partition type is only used as a hint anyway, it's not strictly 
needed. You can even do away with a parition table - unless you want to 
make it bootable. You may have to specify filesystem type at mount time 
though.

e.g.

  # fdisk -l /dev/sdb

  Disk /dev/sdb: 1031 MB, 1031798784 bytes
  16 heads, 32 sectors/track, 3936 cylinders
  Units = cylinders of 512 * 512 = 262144 bytes
  Disk identifier: 0xafe99f91

     Device Boot      Start         End      Blocks   Id  System
  /dev/sdb1   *           1        3936     1007600    e  W95 FAT16 (LBA)

this 1GB drive has one partition - lets make a filesystem with the
entire unit:

  # mkfs -t ext3 /dev/sdb
  mke2fs 1.41.3 (12-Oct-2008)
  /dev/sdb is entire device, not just one partition!
  Proceed anyway? (y,n) y
  ...etc...

  # mount -t ext3 /dev/sdb /mnt
  # df -h /mnt
  Filesystem            Size  Used Avail Use% Mounted on
  /dev/sdb              969M   18M  903M   2% /mnt

  # fdisk -l /dev/sdb

  Disk /dev/sdb: 1031 MB, 1031798784 bytes
  32 heads, 62 sectors/track, 1015 cylinders
  Units = cylinders of 1984 * 512 = 1015808 bytes
  Disk identifier: 0x00000000

  Disk /dev/sdb doesn't contain a valid partition table

Always remember to unmount it rather than just unplugging it.

Gordon

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