FAQs - Mobius 5-Bay

1. My Mobius RAID unit shuts off automatically when not in use. Why?
2. What types of RAID modes does the Mobius 5-Bay support?
3. Why won't my computer recognize my RAID system?
4. How should I format my RAID system?
5. Does the RAID remain connected to the host computer and usable during the automatic mirror rebuild?
6. How do RAID 5 and RAID 5+Hotspare differ from one another?
7. I want to install 4 brand new drives in the Mobius and configure to RAID 5+Hotspare. I want to leave the 5th slot empty so I can install a drive later. Can I do this?
8. I want to remove a drive from the RAID unit and install it in another enclosure for access to the files. How can I do so?
9. What eSATA ExpressCard do you recommend?
10. Can I change my RAID mode array after I have put data on it?
11. I have a 4 drive RAID 5 set and want to add a 5th drive. Can I add the additional drive to dynamically expand the size of my RAID 5 set?
12. Can I create a RAID 1 Mirror with the first two drives and then use the remaining 3 drives as JBOD?
13. The Mobius is connected to a Mac Yosemite computer via FW800. The Mobius appears in Disk Utility, but I am unable to format the drive(s). Why?

If there is no HDD access for 30 minutes, the RAID will go to sleep to save power. The LEDs, drives and fans will turn off. As soon as you access the drive, it will wake up. NOTE: JBOD does not support auto sleep mode.

There are many different types of RAID modes. The RAID modes that are implemented in our line of RAID enclosures include the following:  

RAID 0 (Striping) : Provides increased performance by writing alternating blocks of data (referred to as the stripesize) to 2 or more drivessimultaneously. Read performance is also improved since data is read from all drives at the same time. No redundant information is stored and failure of a SINGLE drive will cause all data to be lost. The number of drives in a RAID 0 array is sometimes also referred to as the stripe width. Total capacity is equal to the stripe width times the smallest drive. 

RAID 1 ( Mirroring) : Provides redundancy by writing all data to 2 or more drives. RAID 1 provides no increase in write performance (it may even be a bit slower). Read performance tend to be faster than a single drive, but not as fast as RAID 0. RAID 1 provides excellent data security since ALL drives has to fail before any data is lost. Total capacity is equal to the smallest drive.

RAID 5 (Striping with distributed parity) : Data and parity is striped across 3 or more drives. Parity is distributed to each drive. RAID 5 is the most widely used RAID for servers and other high performance storage solutions. Any single drive can fail without data loss, ie. at least two drives must fail before any data is lost. Total capacity is equal to the number of drives minus 1 times the smallest drive.

RAID 1+0 (Striping and Mirroring) : Sometimes referred to as RAID 10, this mode combines RAID 0 and RAID 1 by striping a mirrored volume. RAID 1+0 has better data security than RAID 0+1.

JBOD (Just a Bunch Of Drives) : Not actually RAID, 2 or more drives, which can be of any size, are recognized as separate drives by the OS. Since JBOD provides no performance increase and reduced data security, it is seldomly used. 

SPAN (Large) : Spanning combines multiple hard drives into a single logical unit. Unlike Striping, Spanning writes data to the first physical drive until it reaches full capacity. When the first disk reaches full capacity, data is written to the second physical disk. Spanning provides the maximum possible storage capacity, but does not increase performance or safety.

Windows 2000, XP & MAC OS 10.2 (& older) do not support partitions larger than 2TB. In order to support 2TB+ partitions, you must use Windows Vista, Windows 7, or Mac OS 10.3 or higher. Please note: Windows XP 64-bit and Windows 2003 support 2TB+ when using USB & eSATA, but are limited to 2TB when using FireWire.

We strongly recommend performing a Low Level Format of the entire volume after configuring the RAID mode. This will write zeroes to all sectors of the RAID and define where the tracks and sectors of the RAID are located, which will result in optimal performance. 

To perform a low level format using Windows:

1. Download and install HDDGURU Low Level Format Tool.
2. Launch HDDGURU.
3. Choose the RAID volume to Format. Click Continue.
4. Go to Low Level Format Tab, then click Format This Device.
5. It will can take up to 48 hours to finish depending on the connection method and size of RAID.
6. Upon completion, you can now format it with a file system of your choice using Disk Management. Please see FAQ #8.

To perform a Low Level Format using Mac OSX:

1. Configure the RAID and connect it to your Mac.
2. Open Disk Utility. (Applications folder > Utilities > Disk Utility). From the list on the left, click on the external RAID with the size in GB (not the indented item underneath).
3. Click the 'Erase' tab at the top of the application.
4. Select the drop down menu under 'Volume Format' and select Mac OS Extended (Journaled) or another format if desired.
5. Click 'Security Options' and select 'Zero Out Data'. Click Ok
6. Click 'Erase'. You will be presented with an 'Are you Sure' dialog.
7. Click 'Erase' to perform a Low Level format of the RAID volume.

You still can access the data when the RAID is rebuilding, but since it is rebuilding, the transfer speed will be slowed down. Please note: The typical rebuild time is 50GB to 100GB per hour.

Under RAID 5, when one disk fails it must be replaced with a new disk. As soon as it is replaced, the automatic rebuild begins. Under RAID 5 + hotspare, when one disk fails, the automatically rebuild will begin immediately to the spare drive. You can replace the failed disk with a new disk later and the new disk will then be the spare disk.

Yes, if RAID 5+hotspare is desired, insert 4 drives and create the RAID. You may then insert a 5th drive in bay 5 at any time to be used as a hotspare. When a drive fails, the 5th drive will automatically be rebuilt to replace the failed drive.

You can do so for RAID 1 (Mirroring) or JBOD operation.

What eSATA ExpressCard do you recommend?

For either Windows or Mac, we recommend Sonnet Tempo ExpressCard34, part # TSATAII-E342P or Sonnet Tempo Pro ExpressCard32, part # TSATAII-PRO-E34.

 Can I change my RAID mode array after I have put data on it?

The stripesize or stripewidth of a RAID 0, RAID 0+1, RAID 0+1, or RAID 5 array can't be changed without recreating the RAID array. This will cause all data to be lost.

 I have a 4 drive RAID 5 set and want to add a 5th drive. Can I add the additional drive to dynamically expand the size of my RAID 5 set?

No, the Mobius 5-Bay does not allow dynamic expansion of RAID 5 sets. If you have a 4 drive RAID 5 set, and want a 5-drive RAID 5 set, you must clear the existing RAID and create a new one. This will cause the data to be lost.

 Can I create a RAID 1 Mirror with the first two drives and then use the remaining 3 drives as JBOD?

Yes, you can accomplish this as follows:

1. Insert drives in bay 1 & 2 and set the switches for RAID 1.
2. Hold the SET button while powering up. Continue to hold SET until the 2nd beep.
3. Install the remaining 3 drives.
4. Open RAID Manager. Click Advanced Mode.
5. Select the 2nd Icon (Advanced RAID Configuration)
6. Under ‘Create RAID’ select LARGE from the drop down menu.
7. Select an Unreleased drive and click Apply.
8. The selected drive will be configured as JBOD. (Please note, any existing data on these drives will be deleted.)
9. Repeat steps 6-7 for the remaining two drives.

 The Mobius is connected to a Mac Yosemite computer via FW800. The Mobius appears in Disk Utility, but I am unable to format the drive(s). Why?

The issue may be caused by the Yosemite FireWire driver. Please disconnect from FW800 and connect using USB to format the drive(s). After completion, reconnect via FW800 to access the formatted volume(s). .