From: "Timothy Daniels" <
[email protected]>
|
| Well, that's what *I* thought, too, until some guy shared
| in one of these microsoft.public.* NGs that he has
| several times used True Image to clone an internal hard
| drive to a USB external hard drive, then removed the
| external HD from its enclosure and connected it to an
| internal IDE controller and booted from it. Apparently,
| the makers of "USB external hard drives" are merely
| taking their Plain Ole IDE Hard Disk Drives and adding
| a USB/IDE bridge and calling it a "USB drive" while the
| guts - the IDE HD - is still functioning like its ole self.
|
| BTW, the discussion of whether one can *boot* an OS from
| a USB external HD is going hot and heavy in several NGs.
| It seems that some claim that with the newest BIOSes, it can
| be done. And then there are those who claim that it can be
| done with long-existing BIOSes. I'd certainly like to know
| what the state of USB bootability is.
|
| *TimDaniels*
David:
Please see my inline comments...
David H. Lipman said:
To boot off of a a USB device is BIOS dependent. Don't look for it in an
OEM systems but on
a motherboard manufacturers systems such as; ASUS, GigaByte, etc.
As Tim implied, this discussion of whether one can boot from a USB/Firewire
external hard drive has been going for more time than I like to think about.
I've worked with scores of current motherboards and a fair number of USBEHDs
over the past few years. I have NEVER to experienced a single instance where
a USBEHD containing the XP OS was bootable. NEVER. And Lord knows, we've
tried. If I had a dollar for every time someone wrote or said "Yes, a USB
external hard drive is bootable with XP as long as the motherboard's BIOS
supports it", I might not be a millionaire, but I sure would have plenty of
dollars! Yes, I'm aware that *many* motherboards have a BIOS element that
presumably provides this capability. But to no avail in my experience. To
summarize - I've never come across a definitive, documented, confirmed
account of a USBEHD containing the XP OS being bootable. And Lord knows,
I've never experienced it.
Please understand that as far as I can tell, there is certainly no
overriding technical reason why this external drive could not be made
bootable in terms of compatability/support between the BIOS and the XP OS. I
really have no clue why this capability has not been achieved at this late
date. Indeed, Microsoft published a "white paper" some time ago encouraging
motherboard manufacturers to provied USB booting capability in their
products. MS pointed out that there was nothing intrinsically incorporated
in the XP OS that would prevent this capability.
David goes on...
As for the concept of cloning a IDE hard to an external USB chassis then
removing the IDE
drive from the external USB chassis and installing it as an IDE drive...
Sure. No problem
here except one would get faster transfer rates cloning two ide drive,
each on its own IDE
channel. But, it sure is possible as long as the software used to clone
can see the USB (or
FireWire) connected external hard disk.
In our experience the usual scenario is that (using a disk imaging program,
e.g., Ghost, True Image) the contents of the working drive are cloned to the
USB/Firewire EHD for, of course, backup purposes. If & when the time comes
that the working drive must be restored, the contents of the EHD are cloned
back to the internal drive. It's a rare occurrence where the drive in its
external enclosure would be removed from its enclosure and installed as an
internal drive in the machine. But, of course, it can be done. We've done it
many times. (I may even be the "guy" Tim was alluding to!). It is true that
data tranfer rates would be faster using two internal drives rather than
cloning one internal drive to an external one. But that's hardly a practical
consideration in this scenario. The cloning process in virtually every case
is fast enough.
David's final comment...
However, a IDE hard disk cloned to a hard disk connected externally via
USB or FireWire,
even with a bootable BIOS may bot boot off the external drive because the
hardware settings
in the Registry may be incompatible for the OS to work right. It may just
produce a BSoD
and may require a Repair Install. I have not tried it so this is
conjecture.
I'm not really sure I quite understand you here. As I've previously
indicated, to the best of my knowledge a USB/Firewire EHD is not bootable.
As far as I know it has nothing to do with hardware/registry settings or the
like. I think it's something more fundamental than that. Again, this is not
to say that there's something "written in the heavens" that would prevent
such a device from *ever* having that capability. It's just that I've never
experienced it, nor have any of my colleagues and others whose judgment I
trust. But if there's a (current) way to achieve that capability, I'm all
ears. But please, with no offense intended, spare me the "if the BIOS
supports this capability..." routine.
Anna
