Dell Lto5 Manual

LTO-5 Tape Drive User’s Guide37
Chapter 4
Theory
This chapter describes operational theories used in the LTO-5 Tape Drive.
The topics covered in this chapter are:
•Track Layout
•Recording Method on page 38
•Data Buffer
 on page 39
•Data Integrity
 on page 39
•Data Compression
 on page 41
Tr a c k  L a y o u t
With the LTO-5 Tape Drive, there are 1280 data tracks on the LTO tape, 
numbered 0 through 1279. 
The area between adjacent servo bands is a data band. There are 4 data 
bands, each of which...

Chapter 4  Theory
Recording Method
38LTO-5 Tape Drive User’s Guide
A wrap is a track group recorded in the physical forward or physical 
reverse direction. The wraps are recorded in a serpentine fashion 
starting in data band 0. The tape contains 80 track groups, 40 written in 
the forward direction and 40 written in the reverse direction. Even-
numbered wraps are recorded in the forward direction (BOT to EOT), 
and odd-numbered wraps are recorded in the reverse direction (EOT to 
BOT).
Figure 13
 shows...

Chapter 4  Theory
Data Buffer
LTO-5 Tape Drive User’s Guide39
•ONE is represented by a flux transition at the center of a bit-cell.
•
ZERO is represented by no flux transition in the bit-cell.
Data Buffer
In its default configuration, the LTO-5 Tape Drive has a 256-Mbyte 
buffer. The buffer controller has a burst transfer rate of 320 Mbytes/sec., 
and utilizes bank switching to achieve a maximum average bandwidth 
of nearly 240 Mbytes/sec. The high bandwidth is needed to support 
look-aside data...

Chapter 4  Theory
Data Integrity
40LTO-5 Tape Drive User’s Guide
one common symbol between them. The two levels are called C1 and 
C2.
C1 ECC
As data is written to memory from the data processing unit, the DMA/
ECC interface generates C1 ECC bytes and writes them to memory.
As data is written to tape, the C1 ECC is checked and an interrupt 
generated if there is an error. The C1 ECC read from memory is the ECC 
that is written to tape.
When data is read from tape and stored into memory, C1 ECC is checked...

Chapter 4  Theory
Data Compression
LTO-5 Tape Drive User’s Guide41
• For two or more known C1 codeword pairs in error, the matrix is 
computed by firmware and the correction is performed by 
hardware.
• For one or more unknown C1 codeword pairs, syndromes are 
generated by hardware, error location is computed by firmware, 
the matrix is computed by firmware and the correction is 
performed by hardware.
Servo-tracking FaultsDuring a write operation, if the servo system detects an error that may 
result in...

Chapter 4  Theory
Data Compression
42LTO-5 Tape Drive User’s Guide
• The same amount of information can be stored on a smaller length 
of tape.
• More data can be stored on a given length of tape.
• Performance can more closely parallel to that of high-transfer-rate 
computers.
• More information can be transferred in the same time interval.
Data Compression 
Considerations
In an effective data-compression method, several factors are important:
• The amount of compression, which is measured by the...

Chapter 4  Theory
Data Compression
LTO-5 Tape Drive User’s Guide43
Data compression algorithms can be tailored to provide maximum 
compression for specific types of data. Because varying types of data are 
encountered in normal day-to-day operating circumstances, however, 
an effective data compression method for a tape drive must serve 
various data types. Additionally, the data compression method must 
adapt to different data types, automatically providing optimum 
handling for all types of data....

Chapter 4  Theory
Data Compression
44LTO-5 Tape Drive User’s Guide 

LTO-5 Tape Drive User’s Guide45
Chapter 5
Specifications
This chapter provides technical specifications for the LTO-5 Tape Drive.
The topics covered in this chapter are:
•Physical Specifications
•Power Specifications on page 50
•Drive Performance Specifications
 on page 50
•Environmental Requirements
 on page 52
•Injected Noise Specifications
 on page 53
•Reliability Specifications
 on page 53
•LTO Cartridge Specifications
 on page 55
Physical Specifications
Ta b l e  4 lists the physical specifications...

Chapter 5  Specifications
Physical Specifications
46LTO-5 Tape Drive User’s Guide
Table 4  Physical Specifications 
(Half-Height LTO-5)
Figure 14  LTO-5 Half-Height 
Tape Drive Dimensions (front)
SpecificationInternal Drive
Without Bezel With Bezel
Height 1.63 inches  
(41.65 mm)1.68 inches  
(42.70 mm)
Width 5.76 inches  
(146.05)5.86 inches  
(148.99 mm)
Length 8.43 inches  
(214.24 mm)
(Max. to end of 
connector) 8.64 inches  
(219.47 mm)
(Max. to end of 
connector) 
Weight 3.13 lb.  
(1.42 kg.)3.25...