Rescuing Linux Systems--Generic and Distribution-Specific Safety Nets
SuperRescue

Bill von Hagen
Monday, July 8, 2002 11:31:59 AM
H. Peter Anvin's SuperRescue rescue disk
(http://freshmeat.net/projects/superrescue/?topic_id=866%2C861)
advertises itself as "the most overfeatured rescue disk ever created",
and lives up to the name. Based on Red Hat 7.2 (for the most part),
SuperRescue essentially gives you a complete, single-CD version of
Linux that contains everything from basic rescue-related utilities
(fsck, tunefs, fdisk, etc), all the way to a version of the X Window
system pre-configured for 1024x768 (but tunable with the
Xconfigurator utility - also included, of course).
SuperRescue uses a special on-the-fly compression/decompression
mechanism to provide 1.7 GB of binaries on a single bootable
CD. Incredibly, after burning a SuperRescue CD from the downloadable
ISO, booting from it, and starting multi-user mode, I was able to use
the "startx" script to start not only the X Window system, but the
entire KDE desktop. I would have been happy just to get twm, but all
of KDE? Full-featured indeed.
Providing the X Window system is interesting, but the real focus of s
rescue disk is the disk rescue, recovery, restoration, and backup
utilities that it provides, SuperRescue is still reasonably complete
in this respect, providing versions of fsck for the ext2, ext3, and
ReiserFS filesystems. Given the size of SuperRescue and the number of
tools that it provides, I was somewhat disappointed by the absence of
tools and support for journaling filesystems such as JFS and XFS (even
though these often require kernel patches to integrate into the Linux
kernel). I would have traded support for these filesystems for a fair
number of the X Window system utilities that SuperRescue includes, but
that's my personal choice. SuperRescue does provide support for
logical volume management and the physical volumes that underly
it. This makes SuperRescue quite attractive if you are trying to
repair or recover a system that uses standard Linux logical volume
management.
SuperRescue is also a great rescue disk to use if you want to get the
Linux system you're repairing onto a network and integrated with
networked filesystems. SuperRescue includes loadable kernel modules
for the Coda and InterMezzo distributed filesystems as well as
Appletalk, IPX, and SMBFS if you want to mount remote Apple, Novell,
or Windows filesystems and copy data to or from them. It has a limited
number of loadable kernel modules for various PCMCIA Ethernet cards,
but complaining about this is really looking a gift horse in the
mouth.
SuperRescue's bountiful approach to rescuing damaged Linux systems
excels in providing access to a wide variety of utilities that you can
use to back up data from the damaged system that you are
rescuing. SuperRescue includes dump, rdump, tar, cpio, and CD-related
utilities such as mkisofs and cdrecord.
SuperRescue is an impressive piece of work. If you are more
comfortable trying to rescue a Linux system using a graphical
interface, SuperRescue is the only system-independent rescue disk that
includes the X Window system. (There are various small Linux
distributions that provide MicroX or Nano-X, but these are not
specifically designed as rescue disks, and so are outside the scope of
this article.)
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