Boot a Dead PC with Nothing but a Thumb Drive

akezor

When faced with a corrupted hard drive,
system builders know well the aggravation involved in making the
necessary fixes. Such problems usually require a big dig through the
requisite floppy and/or CD system rescue and recovery media. Or worse,
you may have to deal with handmade repair images and associated
specialized recovery tools.
But with the advent of the tiny,
lightweight, and portable USB key drive, system builders now have a new
tool. I believe the USB key drive could alter—even usurp—our old rescue
and recovery methodologies forever.
The USB key drive—also
known as a flash or thumb drive—is most commonly deployed as a storage
or backup utility. But with a few simple conversion steps, you can
transform any key drive into a full-blown rescue and recovery tool. In
this Recipe, I'll take you through those steps. I'll also outline the
advantages, and a few disadvantages, of transforming the key drive into
a bootable utility.
While there are a couple of software
installations involved, both are freeware and easy to deal with. You'll
also need another PC along for the ride when actually performing a full
rescue and/or extensive data recovery—but more on that later. Also
required are any boot floppy images necessary for the recovery process,
which we'll also get into more detail about later. Finally, while the
examples I provide were done on a Linux box, everything I discuss in
this Recipe will work on Windows systems, too.
Ingredients
Here are the essential components you'll need for converting a USB key drive into a bootable utility:
USB
key drive: Any kind or capability will do. In the tests I performed, an
older Memorex TD 2B flash device fulfilled the requirement with 128 MB
(119 MB formatted) of storage space.
Recovery Is Possible
Linux: This specialized, minimal Linux distribution—best known as RIP
Linux—provides recovery tools for both Windows and Linux installations.
It can boot into a workable desktop on many types of hardware. I like
RIP for its small size (35 MB) and because it contains applications
designed for data recovery. RIP Linux weighs in at 72 MB, leaving 47 MB
for additional rescue images (that's more than 30 1.44-MB floppies) and
run-time storage.
SYSLINUX binaries and files: SYSLINUX
provides a minimal boot loader environment for launching into other
rescue, repair, or recovery images, including pared-down Linux or
Windows operating systems. I used SYSLINUX to enable an easy-to-use
boot menu for booting into any number of floppy-emulation images
contained on the USB key drive. In some cases, SYSLINUX must be
obtained separately, as not all Linux distributions may contain its
files by default.
USB-compliant BIOS: This simply means the
BIOS can recognize and boot from USB key drives. Many modern BIOS makes
and models, including Phoenix Award BIOS, are USB-compliant.
Desired
boot floppy images: You'll need any boot floppy images that are
necessary for the recovery process, which will be determined on a
case-by-case basis. Some vendors still issue rescue/recovery floppy
images or driver installers for add-in cards; these make for great
inclusions with this USB key drive solution. These images comprise
drivers, utilities, and configuration data. It's all compressed into a
single 1.44-MB floppy image used to boot a machine into some state to
apply changes, updates, or recover a damaged installation.
An additional working PC: You'll need another (working) PC to create recovery images and modify the USB key drive contents.
Why Choose RIP Linux and SYSLINUX?
There are several compelling reasons why I recommend the RIP Linux rescue system. Here are the ones I consider most compelling:
Ultra-compact
design: Because RIP Linux takes up only 33 MB, it can be used on older
64-MB USB key drives and still leave plenty of headroom.
Flexible
format: Unlike CD and DVD discs, USB key drives use a file system
format that Windows and Linux can easily recognize and use without
additional hardware or software.
Scalable structure:
Vendor-specific and general-purpose recovery utilities can easily be
added to the RIP Linux menu using the SYSLINUX boot loader.
Current applications: RIP uses current applications, and you can include your own as you see fit.
Quick build time: Creating the USB version of RIP Linux completes within minutes.
Easily
adapted and modified: SYSLINUX permits easy boot-loading capability for
a variety of recovery utilities and applications.
While other
software choices exist for this task, I consider these solutions overly
complicated. For example, Feather and Damn Small Linux (DSL) are two
lightweight (50 MB) live-CD distributions. Both distros are designed to
fit on small business-card size CDs for promotions and presentations,
and they can be easily modified into a respectable rescue system. But
they both lack the specialization you'll find in the equally small RIP
Linux.
Here are the three distinct advantages to the USB key method:
Storage
space is writable: You can store data from any computer without
specialty hardware and software, unlike a read-only CD-ROM image (or
writable CD-ROM image without a CD burner!), and with much greater
capacity than a typical floppy.
Smaller, more compact, and less
fragile than CD/DVD: A USB key drives storage medium will never
scratch, and it is much more rigid than CD/DVD discs. Finally, USB key
drives are tiny yet capacious: the smallest are just a tad over two
inches long, yet they can store as much as 2 GB of data.
Easily
expanded, updated and modified for custom use: You can resize, reformat
and repopulate any applications, drivers or utilities necessary to
recover any PC.
To be fair, there are a few drawbacks to the USB approach. Here are three of the worst problems I've spotted:
Not all USB devices boot.
Not all BIOSes boot USB devices.
Not all USB devices that should boot, will boot.
Also,
not all USB storage devices—flash or otherwise—are considered the same
for rescue and recovery purposes. For example, among the products I
tested, neither the Link Depot SD-to-USB adapter with a 1 GB storage
card inside, nor the simple Z-Cyber USB 2.0 iDrive worked as a boot
device. The Link Depot adapter was unrecognized by the BIOS during
boot-up. And the iDrive prevented the BIOS from proceeding through the
power-on, self-test (POST) startup sequence. For a system builder
seeking to troubleshoot an existing rescue or recovery problem, either
device would only complicate matters.
Another issue: Drive
labels for USB devices, which are used to distinguish one storage
volume from another, vary from one BIOS manufacturer and version to
another. Some popular BIOS versions, such as Phoenix Award, identify
the first attached USB device as USB-HDD (hard drive). Others see only
USB-FDD (floppy drive) or USB-ZIP (ZIP drive) devices.
If the
drive label is unclear for a particular BIOS, even with the key plugged
in, try setting the boot priority—and first boot device, if
applicable—to any available USB device name. Remember, not all BIOSes
support bootable USB devices.
That said, the File Allocation
Table 16-bit (FAT16) file system format, originally developed for
MS-DOS, is used in this Recipe for compatibility with most BIOS makes
and models. This will identify either a bootable USB-HDD or USB-FDD
device. It is essential for an all-purpose bootable USB recovery
solution.
Other Uses For a Bootable USB Key Drive
With a little research and testing, you'll find your transformed key drive can also perform the following tasks:
Diagnose disk drives, memory modules, and other hardware.
Obtain detailed hardware reports.
Identify and benchmark CPUs.
Copy partitions to local or network-attached disks.
Reset Windows or CMOS passwords.
Run specialized rescue disks.
Run virus and malware scanners.
Eleven Steps Toward a Bootable USB Key Drive
Let's
walk through creating and configuring a USB key drive for use as a
computer system recovery solution. Here are the 11 steps:
Download the SYSLINUX suite from the SYSLINUX Web site.
Obtain
a copy of the RIP Linux ISO distribution. RIP can be downloaded from
this Recovery Is Possible Linux rescue system page on Tux.org.
Open
the local ISO image and extract the mkusb.sh script for Linux or
mkusb.bat for Windows. (This Recipe uses Linux-specific commands, but
the Windows procedure is roughly the same.) Copy the script to a
temporary working directory along with the RIP Linux ISO.
Run
the script as depicted in the screenshot below. In a matter of minutes
the USB key will receive a fresh Linux installation. Be sure to
identify the appropriate USB device label in the BIOS, as the RIP USB
scripts will automatically select the first available drive assuming it
is the default USB drive entry and proceed to irreparably modify the
corresponding partition entry.




At
this point, RIP Linux is ready to operate directly from the USB key.
The next screenshot illustrates what's necessary for the initial
bootable USB image:
  


Included
recovery applications are limited to what the RIP distribution
provides. Although well populated with a number of handy applications,
RIP does not provide vendor-specific diagnostic tools to troubleshoot a
misbehaving disk drive for example.
The next series of steps demonstrates the process of including additional boot images to the USB key.
Under
Linux, the drive partition will be un-mounted—that is, not visible as a
world-accessible drive partition. Remount the drive or disconnect and
re-plug the USB key to trigger hardware auto-detection facilities to
mount the partition.
Obtain or create the desired boot floppy
image(s) (.img or .igz). For example, an image named my-diags.img. Copy
this file directly into the main directory on the USB key.
Open
the syslinux.cfg file with your favorite text editor (such as vi,
emacs, or joe) and scroll down to the section where the first LINUX (or
lowercase linux) directive is issued, as the following screenshot
shows.




For every boot disk image, there is a corresponding SYSLINUX configuration entry. Each entry has the same basic format:
LABEL [entry]
KERNEL [image]
APPEND [value]
Where
[entry] corresponds to the boot-time image entry, [image] refers to the
image boot loader, and [value] includes any additional boot-time
parameters. Format this accordingly:
LABEL my-diags
KERNEL memdisk
APPEND my-diags.img
The above entry is formatted using our fictitious example values.
Copy
the memdisk boot image to the USB key. This critical file can be found
wherever SYSLINUX sources are installed. On a default Fedora Core
installation, this happens to be situated in the /usr/lib/syslinux
directory.
Repeat steps 6 and 7 for additional boot images,
which may alternatively end in .igz for a gzip-compressed (.gz) image
(.img) file.
Reboot the computer, and trigger the BIOS setup
key. This varies by manufacturer, but is commonly the Delete + Escape +
Function keys, or some combination thereof. Once in the BIOS, seek out
the boot priority or hard-disk sequence settings, and make the USB key
boot first.
Although the initial RIP image is only 72 MB big, the
USB key can quickly grow to several hundred megabytes with the addition
of more drivers, images, and tools. The beauty of this is they can all
be added while the system is booted to the X Windows desktop from the
USB key, which happens to contain the latest version of the Firefox Web
browser.
Native Capabilities of RIP Linux
Next, I'll walk you through some of the things RIP Linux is capable of doing by itself without additional packages.
The
native RIP image is well-stocked with tools to image, edit, and repair
disk or file system partitions, burn CD and DVD media, and even mount
remote storage volumes via Secure Shell (SSH) using the SSH userspace
file system (SSHFS). RIP supports many bus types including IDE, Serial
ATA (SATA), and SCSI for common storage drives and pluggable external
devices by way of USB and Firewire.
Here's a summary of RIP applications:
ClamAV: a free anti-virus program
SSHFS: secure copying across the network with secure shell (SSH)
cmospwd: a utility to reset CMOS passwords
dmidecode: report system hardware as identified by the BIOS
ddrescue: a specialized disk dumping recovery tool
ethtool: query and change network card settings
lshw: list and identify hardware by vendor make and model
ssh: a secure shell server and client package
jfs tools: utilities to recover and repair JFS partitions
xfs tools: utilities to recover and repair XFS partitions
ntfs tools: utilities to recover and repair NTFS partitions
chntpw: a specialized application to change NT passwords kept on NTFS
dirsync: maintain separate but identical archive directories
testdisk: check and undelete various partition formats
cfdisk: a minimal but powerful disk formatting utility
parted/partimage: alternative partition editing utilities
cdrtools: create custom CD formats for recording purposes
dvd-record: create custom DVD formats for recording purposes
When
repairing a Windows-based system, there are software tools for changing
NT passwords (chntpw), manipulating NTFS volumes (mkntfs, ntfsclone,
nftsmount, ntfsresize), and for working with FAT partitions. In fact,
Linux offers a wealth of software options, from platform-specific file
system tools (RAID, LVM, JFS, XFS, and ReiserFS tools), grub and lilo
boot managers, CD and DVD burning applications, and a number of
Internet-related utilities (includig Firefox, e-mail agents, news
readers, and IRC clients).
Ultimately, the USB key-drive
recovery solution saves both time and effort when creating recovery
tools, updating them for use with new software, and testing the final
product. Unlike a CD image, salvageable data can be copied directly to
the USB drive without the need to load an OS or call applications
required to store the data. Flexibility is essential to any working
recovery solution, since features may need to be added, removed, or
changed as necessary; the USB handles all well. Similarly, CD or DVD
disc creation requires at least two additional elements: a CD or DVD
burner and the accompanying software to create a burnable disc. USB is
more efficient, since it is usable as soon as it's plugged into a
computer.
               
               
               

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