Verbatim POWERBAY NAS Array User Manual page 13

RAID 0: RAID 0 (also called Striping) distributes data across all disks
in a way which can improve throughput, while retaining full capacity.
However, RAID 0 provides no fault tolerance so in case of possible
failure of any disk, all data will be lost. Available capacity is the
combined capacity of all four disk cartridges.
RAID 1 with Spare: RAID 1 (also called Mirroring) stores a duplicate set
of data onto at least one other disk so that if one disk fails, all data can
be recovered from the other disk. The PowerBay NAS array implements
RAID 1 in a way that provides for even more redundancy, resulting in
maximum fault tolerance. It does this by (a) using two drives as mirrors
instead of just one, and (b) using the fourth drive as a spare. The spare
drive will automatically rebuild as a fresh mirror whenever a failure of
one of the other three drives is detected. Available capacity is equal to
that of only one disk cartridge.
RAID 5: RAID 5 (Striping with distributed parity) combines three or
more disks in a way that protects data against loss of any one disk. The
storage capacity of the array is reduced by one disk. The PowerBay
NAS array implements RAID 5 in one of two ways:
1. Select "RAID 5" to build a 4-disk array. Available capacity will be
equal to that of three disk cartridges.
2. Select "RAID 5 with Spare" to build a 3-disk array. The fourth disk
is used as a spare. The spare drive will automatically rebuild to
complete a healthy 3-disk array whenever a failure of one of the
other three drives is detected. Available capacity is equal to that
of two disk cartridges.
RAID 6: RAID 6 (Striping with distributed dual parity) combines all four
disks in a way that protects data against loss of any two disks. In the
event of a single disk failure, the use of dual parity allows for time to
rebuild the array safely without the data being at risk if an additional
drive fails before the rebuild is complete. Available capacity is equal to
that of two disk cartridges.
Array Mirroring to eSATA Drive
The full data of the PowerBay NAS array can be continuously copied
to an attached eSATA drive. If a catastrophic failure of the NAS array
occurs, the full data can be restored from the eSATA drive once the
NAS array has been repaired or replaced. Array mirroring to eSATA
is supported only in RAID modes 0, 5, and 6 and is NOT supported in
RAID 1 with Spare or in RAID 5 with Spare. The capacity of the eSATA
drive must be at least as large as the capacity of the NAS array.
If you want to use this function, please enable it during the fi rst time
you confi gure the array.
When the mirror function is in use, the Disk Confi guration page will
show the status of the mirror system, and will present action buttons
to temporarily disable the mirror function ("Unmirror" Button) and to
restore data from the eSATA drive to the NAS ("Restore" Button).
WARNING: When using the eSATA mirroring function, you MUST attach and power
up the eSATA drive BEFORE you power up the PowerBay NAS array. This power-up
sequence must be followed EACH TIME you power cycle the PowerBay NAS array. If you
power up the PowerBay NAS array fi rst, and later attach and power up the eSATA drive,
the eSATA drive will not be recognized as a mirror device, so the eSATA drive will no
longer be synchronized to the NAS data.
Array Encryption
The PowerBay NAS array supports 256-bit Advanced Encryption
Standard (AES) full disk encryption. Encryption may be enabled for
any RAID mode. If eSATA mirroring is enabled, then data copied to the
eSATA drive will also be encrypted.
If you want to use this function, please enable it during the fi rst time
you confi gure the array.
Once the drive has been confi gured using encryption, the full array can
thereafter be LOCKED or UNLOCKED using a password key. When the
array is LOCKED it will not show up on the LAN as a shared volume and
users cannot access it for storage. All four cartridge LED's will remain
red while the array is LOCKED. For convenience, several methods are
provided to UNLOCK a LOCKED array:
1. Enter the NAS user interface and press UNLOCK on the Disk
Confi guration page. You will be prompted to enter the password
key string.
2. Insert a USB Key device into the front USB port of the PowerBay
NAS array. This Key device may be either a fl ash drive or a hard
drive, and must have been previously confi gured with the key
fi le using the 'Store Key in USB Drive' procedure. Once the array
is unlocked, the USB Key device may be removed.
3. Enter the NAS user interface and load the key fi le from a
computer on the LAN using the 'Load" function on the Key
Management page. This key fi le must have been previously
stored onto the computer using the 'Save' function on the Key
Management page. Alternatively, the key fi le might have been
previously e-mailed to a user using the 'Mail' function on the Key
Management page.
NOTICE: When encryption is enabled, data transfer rates may be reduced.
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