Seagate Barracuda 18XL ST318416N, Product Manual

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18 Barracuda 18XL Product Manual, Rev. A
may improve the effectiveness of the short test to find problems more quickly, but in no case will the drive
report a fault condition unless it encounters an actual drive failure.
Each test consists of three segments:
1. Electrical
The drive will read, write, then read a series of sectors that have been allocated in a non-user-accessible
area of the drive. These sectors have been certified at the factory and defective sectors spared. Sequential
sectors will be read, written with a different pattern, then re-read. Each head will be exercised and the data
pattern used will be unique for each head. If any read or write operation fails after retries, the test fails.
2. Servo
This segment executes 4,500 random reads. If any seek fails after retries, DST classifies this as a failure.
3. Read/verify scan
Beginning with logical block address (LBA) 0, the drive scans the user data areas. ECC and retries are
used and all defect management, including the grown list, is used. The scan continues until the time
allowed for the short test has elapsed. If the read of any sector produces an error, DST classifies this as a
failure.
Short Test Correlation
The short test retains a correlation rate of at least 90% with drives tested and classified in the factory, with the
exclusion of media defects. The test reports as “good” at least 90% of drives judged “good” by Seagate tests
and reports as “bad” at least 90% of drives judged “bad” by Seagate tests for reasons other than media
defects.
Extended test (Function Code: 010b)
The objective of the extended test option is to empirically test critical drive components. For example, the seek
tests and on-track operations test the positioning mechanism. The read operation tests the read head element.
and the write element is tested through read/write/read operations. The integrity of the media is checked
through a read/verify scan of the media. Motor functionality is tested by default as a part of these tests.
The extended option performs various tests on the drive and scans every LBA of the drive. The anticipated
length of this test is reported through the Mode Control page.
You can selected which test you want to run through the Function Code field of the Send Diagnostic command.
Each test consists of three segments:
1. Electrical
The drive will read, write, then read a series of sectors that have been allocated in a non-user-accessible
area of the drive. These sectors have been certified at the factory and defective sectors spared. Sequential
sectors will be read, written with a different pattern, then re-read. Each head will be exercised and the data
pattern used will be unique for each head. If any read or write operation fails after retries, the test fails.
2. Servo
This segment performs random seek and read tests. During the random seek test, the drive executes 4500
random seeks. If any of these seeks fail, after retries, DST classifies this as a failure. During the random
read test, the drive executes 4,500 random reads across the full user-accessible area of the drive. ECC
and retries are used. All defect management, including the grown list, is used. If the read of any sector pro-
duces an error, DST classifies this as a failure.
3. Read/verify scan
Beginning with logical block address (LBA) 0 and continuing through the maximum LBA, the drive scans all
user data areas. ECC and retries are used and all defect management, including the grown list, is used. If
the read of any sector produces an error, DST classifies this as a failure.
Extended Test Correlation
The extended test retains a correlation rate of at least 90% with drives tested and classified in the factory. The
test reports as “good” at least 90% of the drive judged “good” by Seagate tests and reports as “bad” at least
90% of drives judged “bad” by Seagate tests.