Services that recover SAN, RAID data
Although most people think of data-recovery services as being aimed at recovering data from a damaged disk or tape, an increasing number of them can now recover data from RAID arrays and SANs as well.
RAIDs and SANs represent a much tougher challenge than a single disk because there are more components involved and the data is usually striped or otherwise split among several physical disks. The data-recovery technicians must untangle the storage volumes and often make fixes to the file system to get at the data. Controller failures, configuration corruption and accidental replacement of media components affect servers and arrays, not just the disks themselves.
One rather ironic result of the added complexity is that recovering data from a SAN or a RAID array can be either much easier or much harder than from a single disk drive. It can be easier because many of the failure modes introduced by these newer systems, such as losing the registry information or a firmware failure, are simple to fix with the kinds of tools the recovery services use. It can be harder because some of the failures, such as data corruption across several volumes on several disks, can be much more catastrophic.
Not all data-recovery services are able to handle these more complex configurations, although it is becoming more common. Among those advertising such services are
Select a data recovery service before you need one. Services are not all alike in expertise or capabilities, and choosing one that is a good match is important. You need to find a service that has experience on your kind of systems, and that comes with good references. Take the time to check those references.
The usual questions about data recovery are how much can be recovered, how long will it take and how much will it cost. The answer to all three is "it depends." How much data can be recovered depends on how much damage was done and can vary from "nothing" to "everything". A typical repair job on a failed hard drive can take from one to five business days, but an atypical job can run a lot longer. The cost depends on the complexity of the recovery job, but typically starts at $500 per drive for a software or firmware failure and $750 for a hardware failure. The cost escalates rapidly into the thousands of dollars or more as the time, technology and knowledge needed to recover the data go up. Many services offer free evaluations and firm estimates, which eases the financial uncertainty at least.
Finally, remember that no one can guarantee he can get your data back. All too often lost is lost forever.
Rick Cook has been writing about mass storage since the days when the term meant an 80K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.
Editor's note: The mention of products or services in this tip is for example only, and does not imply that such products or services listed are an all-inclusive list. Moreover, the mention of such products of services does not imply endorsement of them by SearchStorage.com.
This was first published in March 2002