Beware of Dell RAID Workstations
RAID (Redundant Array of Inexpensive Drives). It’s supposed to be a Good Thing, right? Sometimes yes and sometimes no. There are several kinds of RAID, from Raid 0 through 5 or more. You can have a RAID that stores exactly the same thing on both drives (a Mirror) – which is slower, but fully redundant and safer. Or you can have several kinds of Striped RAIDs, which store data in “stripes” across 2 or more hard drives to provide better performance, but less safety.
Here’s the issue that caused me to write this blog entry. Basically, Dell builds a lot of dual hard drive-equipped home computers configured as a RAID Stripe. This means your data is stored partially on one drive and partially on another. Ostensibly, all files are split 50% on each drive. The problem comes when Windows has some problem (missing file, virus, file corruption, etc.), that prevents you from loading the OS. When this happens, you cannot boot Windows, cannot access your data and cannot, cost effectively, recover your data.
If one drive fails, or Windows becomes corrupt, your data is scattered around all the drives in the RAID and cannot be read or accessed. Recovering this data, if actually possible, is always expensive, because the files have to be reassembled during the recovery process. This is both time-consuming and very expensive. Frequently, your data simply cannot be recovered after one of the drives completely fails, leaving you with a physically OK hard drive that contains only fragments of each file. Useless in terms of recovering your data.
In the case of Dell RAID-enabled machines, we recommend backing up your data and reinstalling the OS, using one drive for the boot volume and the other for data storage.