Page 110 - Automated Fingerprint Identification Systems (AFIS)

FROM PRINT TO IDENTIFICATION 95

5.1.4 RAID STORAGE Figure 5.5
Placement of Minutiae by
The redundant array of independent (or inexpensive) drives, or RAID, is a Coder
feature of AFIS that allows a number of smaller drives to be combined together
to make a larger array, which provides additional features such as improved
performance and data redundancy. The redundancy of smaller disks, faster
input/output, increased capacity, and better security make RAID storage desir-
able for large AFIS systems.
Identification agencies that operate on a 24 hours a day, 7 days a week sched-
ule cannot shut down for maintenance for an extended period of time. RAID
allows more system reliability, since if one disk fails, it will have no impact on
data reliability. To even further minimize the opportunity for system disruption,
an agency may have a redundant or secondary RAID with the same or nearly
the same information as contained on the primary RAID. New records are
added to both the primary and the redundant RAID units. Many larger RAID
arrays can even predict drive failure and contact the vendor, who then imme-
diately ships a replacement, which can be installed in the array before the
failure occurs.
The configuration in Figure 5.1 shows the option of RAID storage of ten-
print images captured at 1,000ppi. While NIST standards require a minimum