On Sun, Aug 11, 2019 at 08:18:54AM -0400, Hendrik Boom wrote:
> On Sun, Aug 11, 2019 at 02:13:48PM +1000, Erik Christiansen wrote:
> > On 10.08.19 21:51, Hendrik Boom wrote:
> > > So I want to find out what's in /dev/sda4 on my hard drive. The
> > > computer has *never* had Windows on it. So I try to mount it, and am
> > > told:
> > >
> > > april:/farhome/hendrik# mount /dev/sda4 /test
> > > NTFS signature is missing.
> > > Failed to mount '/dev/sda4': Invalid argument
> > > The device '/dev/sda4' doesn't seem to have a valid NTFS.
> > > Maybe the wrong device is used? Or the whole disk instead of a
> > > partition (e.g. /dev/sda, not /dev/sda1)? Or the other way
> > > around?
> > > april:/farhome/hendrik#
> > >
> > > Why would it try for and NTFS file system on a Linux machine?
> >
> > To move from speculation to analysis requires information. One way to
> > read the filesystem type of an unmounted filesystem is with blkid, e.g.:
> >
> > $ blkid /dev/sdb1
> > /dev/sdb1: LABEL="fred" UUID="7713e1b5-1bdf-41d1-9aa9" TYPE="ext2"
> >
> > As you have not specified an fstype in the mount command, it'll normally
> > use the blkid libraries to discover the fstype in just this way, so
> > let's see what it finds.
>
> april:/farhome/hendrik# blkid /dev/sda4
> /dev/sda4: PARTLABEL="Linux filesystem"
> PARTUUID="14fdecea-4672-4d03-9660-868f3fd630ec"
> april:/farhome/hendrik#
>
> And if it doesn't mention type, should I presume that it's likely a
> partition that does not have a file system installed? Or at
> least not one the current Linux system can handle?

That may be true. You can also check with “wipefs” tool (don't worry,
without -a it won't wipe anything):

wipefs --no-act /dev/sda4

Wipefs has a big database of various filesystem metadata, it detects
almost anything.

-- 
Tomasz Torcz                Only gods can safely risk perfection,
xmpp: zdzichubg@???     it's a dangerous thing for a man.  -- Alia