Fujitsu MAB3045 Computer Drive User Manual


 
C141-E035-03EN3 - 4
(1) User space
The user space is a storage area for user data. The data format on the user space (the length of
data block and the number of data blocks) can be specified with the MODE SELECT or
MODE SELECT EXTENDED command.
The default number of cylinders in the user space is 9,041 for MAA31xxxx, 8,491 for
MAB30xxxx and 8,691 for MAC30xxxx. The user, however, can select the number of
cylinders to be allocated in the user space by specifying 9,041 for MAA31xxxx, 8,491 for
MAB30xxxx and 8,691 for MAC30xxxx as the maximum and the number of alternate
cylinders + 1 as the minimum. The user can also specify the number of logical data blocks to
be placed in the user space with the MODE SELECT or MODE SELECT EXTENDED
command. When the number of logical data blocks is specified, as many cylinders as required
to place the specified data blocks are allocated in the user space.
A number starting with 0 is assigned to each cylinder required in the user space in ascending
order. If the number does not reach 9,041 (MAA31xxxx), 8,491 (MAB30xxxx) and 8,691
(MAC30xxxx), the rest of the cylinders will not be used.
Always one alternate cylinders can be established in the user space. Alternate cylinders will
be used for alternate blocks when primary cylinders in the user space are used up. See
Subsections 3.1.2 and 3.3.2 for details.
(2) Internal test space
The Internal test space is an area for diagnostic purposes only and its data block length is
always 512KByte. The Internal test space consists of only 1 cylinder and outer-host cylinder
is always assigned. The user cannot change the number of cylinders in the Internal test space
or their positions.
The IDD reads or writes the data block in the Internal test space during the self-diagnostic test
specified with a SEND DIAGNOSTIC command.
(3) System space
The system space is an area for exclusive use of the IDD itself and the following information
are recorded. The length of the data block is always 512 bytes.
Defect list (P list and G list)
MODE SELECT parameter (saved value)
Statistical information (log data)
Controller control information
The above information are duplicated in several different locations for safety.
Note:
The system space is also called SA space.