June 2, 2004

Drive recovery comes to Linux

Author: Mary E. Tyler

Fire. Flood. Having a five-foot-thick redwood tree fall on your home
office. Collectively, these are disasters that can befall your
computers' hard drives. At an enterprise level add in dead multi-disk
servers, RAIDs that get mixed up, and network storage appliances that
don't get backed up. Whether you're a homeowner mourning the loss of your
family's digital picture album or an enterprise-level IT director
trying to make sure that your next disaster doesn't involved getting
canned, there is a solution.

Drive recovery has long been the last resort of IT directors (and
desperate dissertation writers). In recent years, industry leaders DriveSavers Inc. and Kroll OnTrack Inc. have added Linux
recovery to their service lines, but you'd never know from looking at
their Web sites. DriveSavers doesn't even mention that it handles
Linux drives -- it has recovery tips for Macs and PCs, but none for
Linux. Ontrack
hides support for Linux three levels deep.

Both companies agree, for recovery purposes, a drive is a drive at
the component level. Both companies work with a variety of drive
manufacturers and maintain inventories of parts and clean room
facilities. However, there can be variation at the file system level.
Both companies handle a range of Linux file systems. "OnTrack
supports EXT2, EXT3, XFS, and ReiserFS," says Ontrack's director of
software and services Jim Reinert. "Our tools and procedures become
specialized for each file system." When asked what file systems
DriveSavers supports, John Christopher, a data recovery engineer and
spokesman for DriveSavers, answers with a simple and unquantified
"all of them."

Though both DriveSavers and OnTrack are leaders in the
recovery niche, they have different philosophies about recovery. OnTrack
attempts to diagnose a drive first, so it can provide an
estimate before recovering the data. OnTrack also has a free downloadable
utility you can use yourself if your drive is still

DriveSavers has a different viewpoint. "No one can tell
if your data is recoverable until they actually recover it. It's
impossible," states Christopher. "[Spinning up the disk] puts your
data at risk. Many times, you have only one chance. If you keep the
drive going, you could make the situation worse." DriveSavers won't
spin up your drive and diagnose it because that one time could be the
only chance the drive has. They give estimates based on experience
and the size and condition of the drive. Assuming that the drive
mechanism is damaged, they make a bit-by-bit copy, cloning everything
on the drive, and then recover from that copy.

Both companies offer in lab services for Linux at various service
levels. "You're buying time," explains Reinert. "How fast do you
need the data back?" DriveSavers offers three levels of service:
economy, five to seven days to recovery; standard, one to two days;
and priority, "as soon as possible" including weekends and holidays.
Ontrack has four levels of in-lab service. Standard puts your drive
in the queue to be recovered during regular business hours. Priority
jumps you to the head of that line at every stage, but still means
your data might sit over a weekend. Weekend service means techs will
work Saturday or Sunday to recover your data. At the Emergency level,
technicians work "around the clock, non-stop" to recover data. Both
companies offer on-site service where their people come to you. If
your drive is functioning, you
may be able to use Ontrack's remote recovery service, which involves
downloading an Ontrack application that attempts to diagnose drive problems and then recover what data it can. "The benefit is
return time," says Reinert. "Remote service gets your data back

Hard drive triage

Knowing when to call in a recovery service is not difficult. If
there's nothing wrong with the drive itself, for example if the admin
has reinstalled Linux over old data and then needs that data back, or
a RAID has gotten mixed up, it's fine to spin up the drive. "If the
drive appears to be functioning, but the volumes are down, you can
run our free diagnostic," says Reinert. "If the drive is spinning and
readable, recovery can proceed." But he cautions against messing with
a damaged drive. "If the drive is clicking or won't spin, if it's
discolored or has been close enough to a fire to make a visual impact
or has water damage, I would not spin that drive up." Christopher
agrees, but notes that the advice is seldom followed. "By the time we
get a drive, it's been through the wringer. Most people go to their
spouse for help, then to a relative or friend, then to a local
computer repair shop. There has probably been media damage from spinning
the drive up and down. We always assume a drive is on its last legs."

Both companies agree, if the drive has smoke damage, get the data
off it and replace the drive. According to Reinert, every drive is
sealed with a filter. The seals and filters are rated as to what size
particles they can keep out. Particles smaller than the minimum can
get in. If the
drive has been damaged by smoke then it could fail at any time -- could
be tomorrow, could be two years from now. Christopher sums it up
neatly: "If you're lucky enough to survive whatever disaster has
occurred, back up the data and replace the system. Do you really want
to gamble? Things are perfectly fine until the moment a problem

It's not cheap

No one ever claimed data recovery was inexpensive. DriveSavers has
a $200 attempt fee whether they recover any data or not. It can
recover flash media, like that used by digital cameras, for a flat $200 as
well. OnTrack is in the same line. They charge a $100
diagnosis fee and quote a basic single-disk recovery at $1,000.
Recovery fees vary based on size and condition of the drive, need for
clean room services, security requirements, and service
level/turnaround time.

To the surprise of many, data recovery services may be covered by your
insurance company in the cases of fire, flood, and the like. Most
insurance adjusters are not familiar with data recovery services and
don't even know they exist, but that doesn't mean your policy won't cover
all or part of a recovery. It just means you have to ask. Homeowner
William George of Newport News, Virginia, has personal experience with
the subject. "After our house fire, our homeowners insurance was
willing to pay for recovering data from our smoke-damaged hard
drive, even though they estimated nearly $3,000. Fortunately, we were
able to back up the data ourselves. If we didn't ask, we would never have
known that the policy would pay for recovery. It didn't say
anything specifically for or against it."

When disaster strikes, recovery is a last resort of the desperate.
"People need us only when something goes wrong," Christopher says.
"We're the brain surgeons of the computer world. We try to be
proactive, to pass the word that it's important to back up. You can
take steps to protect your data, but every backup plan created to
prevent data loss has holes. Drive recovery is the last line of

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