Seagate Fibre Channel Interface User Manual
Page 176
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Fibre Channel Interface Manual, Rev. D
Interleave
This field requests that logical blocks be related in a specific fashion to the physical blocks to facilitate data transfer speed
matching.
0
The target uses its default interleave.
1
Consecutive logical blocks will be placed in consecutive physical order.
Š2
One or more (respectively) physical blocks separate consecutive logical blocks. The disc drive implements an
optional prefetch (read look ahead) function which reads a user-specified number of sectors into its buffer beyond
and contiguous to the sectors requested by the read command. This data is subsequently available for the next
sequential read command without re-access of the disc media thereby increasing performance and negating the
need for an interleave during format if this prefetch option is enabled (see Read Command, Section 12.21). Inter-
leave values other than zero or one are vendor specific.
The following definitions of flaw categories are supplied to help you understand the alternatives listed in Table
97.
P
Primary Defect Type: P type flawed sectors are identified at the time of shipment in a list of defects (permanent
flaws) supplied by Seagate and stored on the disc in an area that is not directly accessible by the user. (This list may
be referred to as an ETF List). This defect list is not modified or changed by the disc drive (or initiator) after ship-
ment.
C
Certification Defect Type: C type flawed sectors are sectors that fail a format verify during the format function.
D
Data Defect Type: D type sectors are sectors identified in a list supplied to the target by the initiator during a Format
Unit command. The D List follows a four-byte defect list header and is referred to as Defect Descriptor Bytes.
G
Growth Defect Type: G type flawed sectors contain medium flaws and have been reallocated as a result of receiving
a Reassign Blocks command, or certification defects (C type) reallocated during a previous Format Unit command,
or Data Defects (D type) reallocated during a previous Format Unit command or defects that have been automati-
cally reallocated by the drive. This (G) list is recorded on the disc drive media and may be referenced for the current
(and subsequent) Format Unit commands. This (G) list does not include the Primary (P) list of defects.