Download DVR Express User Guide

3.3.2 Disk Signatures
Before a disk drive can be used to store video it requires a disk signature. A disk
signature is simply a unique sequence of bytes written to a specific location on the disk
drive. The DVR Express software uses this signature to identify the disk drive as a DVR
Express disk drive. Please note that writing a disk signature overwrites existing
information on the disk drive and will almost certainly destroy any existing file system on
the drive (e.g. FAT or NTFS). If the DVR Express software detects a new drive without
a valid disk signature, the software automatically attempts to write a disk signature unless
otherwise instructed by the user. Drives without disk signatures cannot be used by the
DVR Express.
3.3.2.1 Writing Disk Signatures
Normally, disk signatures are automatically written when the DVR Express software
detects a new drive. In certain cases it may be necessary to manually write/re-write a
disk signature. To perform this operation, first select one or more drives in the Drives
Attached to Device list. Next, choose the Write Signature option from the Array menu.
Disk signatures can be written to all drives connected to a device in a single operation by
selecting all the drives connected to the device.
3.3.2.2 Checking Disk Signatures
Disk signatures can be verified by choosing the Check Disk Signatures option from the
Array menu. Disk Manager checks all drives connected to all devices for signatures and
displays a warning message if drives are detected that do not have valid disk signatures.
3.3.3 Disk Arrays
Disk Arrays are logical groupings of disk drives. To understand the function of a disk
array, consider the following example. Suppose a system is configured with four DVR
Express devices each having three disk drives for the purpose of recording video from a
four-tap camera. In this case, before recording any video, a disk array must be created
that logically groups all 12 drives together. The array would require a name (e.g.
“DVR”) and each drive in the array would be assigned a “tap” number between 1 and 4
and a “drive” number ranging from 1 to 3. This information is stored on each disk drive
in the array.
3.3.3.1 Creating a Disk Array
To create a disk array, select the Create New Array option from the Array menu. When
prompted, enter a name for the array. The name may contain any printable character
including spaces. Please note that the name is automatically capitalized. After entering
DVR Express: Section 3
17