Knowledge Base

Data Recovery | Backup Solutions | Service Contracts

For instance, in the FAT file system, when two files claim to share the same allocation unit ("cross-linked"), data loss for one of the files is essentially guaranteed. The increased use of journaling file systems, such as NTFS 5.0, ext3, and XFS, is likely to reduce the incidence of logical damage. These file systems can always be "rolled back" to a consistent state, which means that the only data likely to be lost is what was in the drive's cache at the time of the system failure. However, regular system maintenance should still include the use of a consistency checker. This can protect both against bugs in the file system software and latent incompatibilities in the design of the storage hardware. One such incompatibility is the result of the disk controller reporting that file system structures have been saved to the disk when it has not actually occurred. This can often occur if the drive stores data in its write cache, then claims it has been written to the disk. If power is lost, and this data contains file system structures, the file system may be left in an inconsistent state such that the journal itself is damaged or incomplete. One solution to this problem is to use hardware that does not report data as written until it actually is written. Another is using disk controllers equipped with a battery backup so that the waiting data can be written when power is restored. Finally, the entire system can be equipped with a battery backup (see UPS) that may make it possible to keep the system on in such situations, or at least to give enough time to shut down properly.

Some kinds of logical damage can be mistakenly attributed to physical damage. For instance, when a hard drive's read/write head begins to click, most end-users will associate this with internal physical damage.

This is not always the case, however. Often, either the firmware on the platters or the controller card will instead need to be rebuilt. Once the firmware on either of these two devices is restored, the drive will be back in shape and the data accessible (From Wikipedia, the free encyclopedia).

[Page 1][Page 2][Page 3][Page 4]

Login to our Live Chat and get support instantly! Or, browse our Frequently Asked Questions and Knowledge Base articles!

Copyright (C) 2011 Target Data Recovery