Cause:
The cause of this issue is unknown.

Resolution:
To resolve this issue, please connect the My Book Studio II via USB or 1394b (FireWire800) and perform the RAID change again.

Cause:
If the second drive is assigned the same unix device name that was assigned to the RAID device before it was dismounted from the system, the second drive will be reformatted.

Solution:
External drives should not be removed or attached during a RAID change operation.

Dismantle the unit and replace the faulty hard drive. Once the hard drive has been physically replaced and the unit has been reassembled, please follow the directions below to format and mirror the existing data to the new replacement hard drive.

Ensure that the WD My Book World (Blue Rings) storage system is powered on and is detected by WD Anywhere Access and your network.

1. Access the Shared Storage Manager utility through WD Anywhere Access by clicking on File and then on Manage MyBookWorld.
     

   

2. Click on the WD Anywhere Access Settings option. The "Enter Network Password" screen will appear. Enter your WD Anywhere Access Username and Password in the User Name and Password fields and then click on the OK button. The WD Anywhere Access options are displayed.
   
3. Click on the Stop button to stop the WD Anywhere Access program from running on the WD My Book World (Blue Rings). The Status will change to show that MioNet is NOT Running (Inactive).

   

4. Click on the Drive Management(Advanced) option. The Drive Management screen will be displayed. Notice in the top right corner that the new replacement hard drive is detected with a status of: "Drive x Failed".
   
5. Click on the Format New Internal Drive option.

   

6. Click on the Yes I’m Sure button.

   

7. At this point, the formatting and mirroring process of the replacement hard drive will start. The page will display a formatting progress notification screen.
   
8. If you press the F5 key on the keyboard or click the Refresh button on your web browser, the "Drive Status:" will change from "Drive x Failed" to Synchronizing.
   
9. Important: The RAID mirroring process (to mirror the data onto the replacement hard drive) will take approximately 5 hours, regardless of how much data is actually on the unit. Please ensure that the WD My Book World (Blue Rings) storage system is not turned off or accessed during this process.
   Once the Mirroring process has been completed, you will need to restart the Mionet/WD Anywhere Access program on the drive.
10. Click on the WD Anywhere Access Settings option. The "Enter Network Password" screen may appear. If it does, enter your Mionet/WD Anywhere Access Username and Password in the User Name and Password fields and then click on the OK button. The WD Anywhere Access options are displayed.

    

11. Click on the Sart button to start the MioNet/WD Anywhere Access program on the WD My Book World (Blue Rings). The Status will change to show that MioNet is Active.
     

RAID Hardware is always a disk controller to which you can cable up the disk drives. RAID Software is a set of kernel modules coupled together with management utilities that implement RAID in Software and require no additional hardware.

Pros and cons

Software RAID is more flexible than Hardware RAID. Software RAID is also considerably less expensive. On the other hand, a Software RAID system requires more CPU cycles and power to run well than a comparable Hardware RAID System. Also, because Software RAID operates on a partition by partition basis where a number of individual disk partitions are grouped together as opposed to Hardware RAID systems which generally group together entire disk drives, Software RAID tends be slightly more complicated to run. This is because it has more available configurations and options. An added benefit to the slightly more expensive Hardware RAID solution is that many Hardware RAID systems incorporate features that are specialized for optimizing the performance of your system. For more detailed information on the differences between Software RAID and Hardware RAID you may want to visit: www.adaptec.com

Assess the needs of your system and then decide which RAID solution works best for you. Please do keep in mind however, that regardless of which RAID solution you choose, neither can provide against administrator (human) error. Therefore, frequent, regularly scheduled back ups of your system are highly recommended.

Drive randomly marked dead (off line) by SCSI controller.

There are many reasons why a SCSI controller or operating system marks one or more drives off line. Here is a list of common issues, likely to cause a drive to be remarked off line–dead.

It’s important to make sure the cabling, termination, and drive enclosure hardware is suitable based on SCSI specification–or as required by your configuration. Use the best quality SCSI data cable. Make sure it is certified for either Ultra SCSI or Ultra 2 or Ultra 3(Ultra 160) or Ultra 320 SCSI. Most SCSI controller vendors support a line of cables and terminators for their product.

If there is a mix of LVD (low voltage differential) and non-LVD devices on any one SCSI channel? Then Ultra SCSI (single-ended narrow) specifications apply–cables not longer than 1.5 meters, and not more than four devices supported. Both LVD cables and termination devices are available from: Granite Digital at 510-471-6267, and TMC at 415-454-5425. A distributor or computer reseller may sell LVD SCSI data cables and terminators.

Not enough SCSI Termination Power can be at fault. As a precaution, be sure the last two physical devices (hard drives) on each SCSI channel, provide Term. Power to the SCSI bus. For SCSI bus Termination Enable, we highly recommend you use either the disk array enclosure (if supported) or a system terminator at cable end. If you use LVD drives, you must use an LVD terminator. If you are using SCSI single ended devices, or mixing single-ended and LVD you must use an active terminator at cable end.

Sometimes the disk array enclosure, the drive slide trays may be defective, or there could be a problem with the SCA back-plane logic board. Try the drive in a different system–does the failure follow to another ‘known good’ platform?

The system power supply can be at fault. Under or over current will cause the drive to spin down in the name of data integrity. You will want to make sure a high quality power supply is used, and that it will meet the power needs of your system.

Software drivers and BIOS on the SCSI RAID controller can affect timing and communications. You should visit all system component and operating system manufacturer’s Web sites, to confirm that all drivers and firmware is up to date.

Once complete, the Add Hardware Wizard will prompt again to load driver support for a "Promise SATA Console Processor Device". You won’t be able to load a driver for this device so just ignore it. Cancel the Add Hardware Wizard.

After this is done, the Device Manager should show two new listings. One should be under "SCSI and RAID controllers" and should be listed as "Win(x) Maxtor SATA/150 PCI Card". The other should be under "Other Devices" with a question mark next to it. This is the "Promise SATA Console Processor Device". Again, ignore this device. A driver cannot be loaded for it.

Once a SATA or PATA drive is connected to the card, the "Promise SATA Console SCSI Processor Device" listing will go away. If all drives are disconnected from the card, the Add Hardware Wizard will reappear when the system is booted.

Additional Information:

The Promise SATA150 TX2plus drivers will work with the Maxtor SATA/150 controller cards since they are based on the same hardware but are not supported by Maxtor. They do not address this issue but have various compatibility fixes:

http://www.promise.com/support/download/download2_eng.asp?productId=97&category=driver&os=0

Try the following troubleshooting steps:

1. Check all cable connections. Test the data cable by trying a different cable or try the cable on a known working drive.
2. Confirm the jumper settings.
3. Check termination.
4. Check the host adapter card. Test the card by either trying a known good card or a known working drive.
5. Check host adapter settings. Set to asynchronous negotiation and the transfer rate to 10MB/s. (or the slowest setting).
6. Make the offending drive the only SCSI device in the system and re-test.
7. Run the low-level format routine provided by the host adapter manufacturer.
8. Try the drive in a different system.

Drive randomly marked dead (off line) by SCSI controller.

There are many reasons why a SCSI controller or operating system marks one or more drives off line. Here is a list of common issues, likely to cause a drive to be remarked off line–dead.

It’s important to make sure the cabling, termination, and drive enclosure hardware is suitable based on SCSI specification–or as required by your configuration. Use the best quality SCSI data cable. Make sure it is certified for either Ultra SCSI or Ultra 2 or Ultra 3(Ultra 160) or Ultra 320 SCSI. Most SCSI controller vendors support a line of cables and terminators for their product.

If there is a mix of LVD (low voltage differential) and non-LVD devices on any one SCSI channel? Then Ultra SCSI (single-ended narrow) specifications apply–cables not longer than 1.5 meters, and not more than four devices supported. Both LVD cables and termination devices are available from: Granite Digital at 510-471-6267, and TMC at 415-454-5425. A distributor or computer reseller may sell LVD SCSI data cables and terminators.

Not enough SCSI Termination Power can be at fault. As a precaution, be sure the last two physical devices (hard drives) on each SCSI channel, provide Term. Power to the SCSI bus. For SCSI bus Termination Enable, we highly recommend you use either the disk array enclosure (if supported) or a system terminator at cable end. If you use LVD drives, you must use an LVD terminator. If you are using SCSI single ended devices, or mixing single-ended and LVD you must use an active terminator at cable end.

Sometimes the disk array enclosure, the drive slide trays may be defective, or there could be a problem with the SCA back-plane logic board. Try the drive in a different system–does the failure follow to another ‘known good’ platform?

The system power supply can be at fault. Under or over current will cause the drive to spin down in the name of data integrity. You will want to make sure a high quality power supply is used, and that it will meet the power needs of your system.

Software drivers and BIOS on the SCSI RAID controller can affect timing and communications. You should visit all system component and operating system manufacturer’s Web sites, to confirm that all drivers and firmware is up to date.

However, if you must replace a failed drive, it can sometimes be difficult to find the same model if that model is out of production. Below are some tips to follow when selecting a replacement.

Keep in mind that the controller may or may not allow different models in a RAID, so check the RAID controller documentation.

• Product life: What is the expected life of the remaining drives? If the other drives are approaching the end of their useful life, then it may be time to replace the entire RAID.
• Capacity: The replacement drive should be the same or higher capacity than the original drive. Do not just look at the capacity on the box, since a few megabytes could make the difference between whether the drive will work or not. 
  You should check the number of LBAs (or sectors) on the drive. Some RAID controllers will allow you to substitute larger drives if the exact capacity is not available, while other controllers require an exact match. Check with the controller manufacturer if the documentation doesn’t make it clear. 
• Performance: The replacement drive should match the performance of the remaining drives as closely as possible. If your failed drive was 15,000 RPM, avoid replacing it with a 10,000 RPM drive. RAID arrays depend on the timing between drives to write data. Thus, if one drive doesn’t keep up, it may cause the entire array to fail or at least experience irritating problems.
• Interface: Make sure the replacement drive uses the same type of interface connection as the failed drive. If the failed drive used a SCSI SCA (80-Pin) interface then don’t try to replace it with a 68-pin SCSI interface. With Seagate products the last two digits of the model number indicate the interface.
  For example:
  LW = 68-Pin
  LC = 80-Pin
  The 80-pin LC drives are hot-swappable with backplane connections.
• Cache Buffer: It is recommended that the cache buffer for each drive be the same value.  Most RAID controllers will consider drives with mismatching cache buffers to be ineligible for addition to a striped or parity array.