Ну вот и нашлось похоже нормальное устройство, люди в мануале описывают что и как происходит - и это очень радует:
http://www.areca.com.tw/products/esataf ... aoeusb.htm
• Hard Drive Failure Prediction
In an effort to help users avoid data loss, disk manufacturers are now incorporating logic into their drives that acts as an "early warning system" for pending drive problems. This system is called SMART. The disk integrated controller works with multiple sensors to monitor various aspects of the drive's performance, determines from this information if the drive is behaving normally or not, and makes available status information to RAID subsystem firmware that probes the drive and look at it. The SMART can often predict a problem before failure occurs.
The controllers will recognize a SMART error code and notify the administer of an impending hard drive failure.
• Auto Reassign Sector
Under normal operation, even initially defect-free drive media can develop defects. This is a common phenomenon. The bit density and rotational speed of disks is increasing every year, and so are the potential of problems. Usually a drive can internally remap bad sectors without external help using cyclic redundancy check (CRC) checksums stored at the end of each sector. RAID subsystem drives perform automatic defect re-assignment for both read and write errors. Writes are always completed - if a location to be written is found to be defective, the drive will automatically relocate that write command to a new location and map out the defective location. If there is a recoverable read error, the correct data will be transferred to the host and that location will be tested by the drive to be certain the location is not defective. If it is found to have a defect, data will be automatically relocated, and the defective location is mapped out to prevent future write attempts. In the event of an unrecoverable read error, the error will be reported to the host and the location will be flagged as being potentially defective. A subsequent write to that location will initiate a sector test and relocation should that location prove to have a defect. Auto Reassign Sector does not affect disk ыubsystem performance because it runs as a background task. Auto Reassign Sector discontinues when the operating system makes a request.
• Consistency Check
A consistency check is a process that verifies the integrity of redundant data. To verify RAID 3, 5, and 6 redundancy, a consistency check reads all associated data blocks, computes parity, reads parity, and verifies that the computed parity matches the read parity. Consistency checks are very important because they detect and correct parity errors or bad disk blocks in the rive. A consistency check forces every block on a volume to be read, and any bad blocks are marked; those blocks are not used again. This is critical and important because a bad disk block can prevent a disk rebuild from completing. We strongly recommend that you run consistency checks on a regular basis—at least once per week. Note that consistency checks degrade performance, so you should run them when the system load can tolerate it.
Пробовали... сделали зеркало, вытащили один диск, сказали - а ну ка восстанови! А он сказал - а не пошли бы вы... Ну мы пошли и сдали его обратно
