bootable ext. USB SSD for backup

Polytropon freebsd at
Fri Mar 17 09:17:12 UTC 2017

On Thu, 16 Mar 2017 19:47:52 -0700, Mehmet Erol Sanliturk wrote:
> On Thu, Mar 16, 2017 at 12:46 PM, Matthias Apitz <guru at> wrote:
> >
> > Hello,
> >
> > I have acquired a small and flat USB 3.0 external disk (must be SSD for
> > the size of the case):
> >
> > Mar 16 19:36:54 c720-r314251 kernel: da0: <TOSHIBA External USB 3.0 5438>
> > Fixed Direct Access SPC-4 SCSI device
> > Mar 16 19:36:54 c720-r314251 kernel: da0: Serial Number 20170114010787F
> > Mar 16 19:36:54 c720-r314251 kernel: da0: 40.000MB/s transfers
> > Mar 16 19:36:54 c720-r314251 kernel: da0: 953869MB (1953525164 512 byte
> > sectors)
> > Mar 16 19:36:54 c720-r314251 kernel: da0: quirks=0x2<NO_6_BYTE>
> >
> > Ofc it has not the promised 1 TB volume, just only 953869 MB, i.e. only
> > 1 Marketing-TB;
> >
> > I'm thinking in re-partitioning the disk (which is actual only one big
> > NTFS slice) with gpart(8), install even a kernel into a small FS at the
> > beginning and keep the rest as a big UFS for backups. Having it bootable
> > with a system could be handy if one has to rescue a system and restore
> > the last dunp.
> >
> > Any ideas/comments
> >
> >         matthias
> > --
> > Matthias Apitz, ✉ guru at, ⌂> > +49-176-38902045
> > _______________________________________________
> >
> >
> I am sorry to respond with respect to Linux . I think that FreeBSD will be
> a little similar .
> When NTFS external disk is used , it is not necessary to "mount" it : It is
> directly handled with LOSS of access right information of files .

That doesn't seem to look correct. FreeBSD needs to mount the
NTFS partition in order to access it. There are different ways
to do this, though. Today FUSE is recommended. However, NTFS
is not a good choice for making backups (data corruption and
data loss, limited support among non-"Windows" systems etc.).
For NTFS, ntfs-3g is the required component. A system-provided
mount_ntfs binary (sufficient for r/o operations) does not
exist anymore in recent FreeBSD versions. But ntfs-3g will
support r/w operations and many NTFS features; see "man ntfs-3g"
for details. Also check the port "ntfsprogs" for additional
tools that might be useful when dealing with defective NTFS.

As you correctly mentioned, access rights (and other kinds of
file attributes) are a problem on NTFS and FAT (MSDOSFS). If
you need to store such information, you'd better put your files
inside a tar archive which will preserve all that information,
and additionally deal with the problem of forbidden characters
and file names that exist on NTFS and FAT (and "Windows" in

> When a Linux file system is used , it is necessary to "mount" it for using
> it . You need to use it either as "root" or find a way to use it as a
> "user" .

Mounting Linux file systems also works fine with FUSE, you just
have to make sure you install the required FUSE modules, depending
on _which_ kind of Linux file system (there are many!) you want
to access. Mounting things as a non-root user requires some
little configuration changes, explained here:

Look for "vfs.usermount", device permissions and mountpoint (target
directory) permissions.

> If it is bootable , with respect to my use of Fedora ( it may depend on
> version ) , booting is starting from external drive , but somewhere there
> is a "fixed" or "hard-coded" sda , etc. . When it is encountered , booting
> is switching to internal HDD . To prevent this switching , it is necessary
> to disconnect power of internal HDD units .

This can be avoided by using labels which are unique to the USB
medium, so no more device names are involved in the boot process.

> The above issues are possible difficulties .

Which can be solved easily. ;-)

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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