IBM IC35L018UCDY10, Specifications

Page: 230 / 249

!
Drive ready check is to check the voltage status of 12V.
!
RAM test is a read/write test for the whole area of sector buffer.
!
Spin check is to check if the spindle motor is running at the correct speed.
!
Write, Read and Compare test is a disk read/write test. It writes data to a certain area in the reserved
area and read it from the same area to validate. Head 0 is used for this test.
!
ECC circuit test is a test for ECC circuit if errors can be corrected by the circuit.
!
Seek test is a test for servo. It seeks random 256 locations out of full volume.
!
Low level format check is to check if the media is in the Media Format Corrupted state.
!
Physical head test is a disk read/write test using the reserved area on each head.
!
Read scan test is a read test. It reads the area specified in the above table.
!
SMART check is to check the SMART test logs and results.
11.18 Idle Time Function
The drive performs the following functions to maintain the disk surface:
!
At 1 second idle after any media access command, the head is moved to a random cylinder.
!
At accumulated nominal 60 times of 1 second idle, the sweep function from a middle of disk to the
cylinder 0, then a middle of disk to the most inner cylinder. The sweep function moves the head
slowly using a series of short seeks. After the sweep function, the head is moved to a random cy-
linder. The count of nominal 60 has a randomness from 54 to 66 based on the serial number of the
drive to avoid synchronized noise of the sweep in a system box. If a media access command is
received during the sweep function, it is interrupted to service the host command. The next sweep
function after the accumulated 60 times of 1 second idle starts from where it has been interrupted.
!
At 1 second idle after 10 days from the power on or previous one, the head is unloaded to sweep the
outside of cylinder 0. The head is loaded by a media access command or by the sweep function, and
it stays unloaded at least for 2 seconds to reduce fluttering. The execution time of sweep function is
about 2 seconds.
In addition, the drive periodically saves the PFA counters to the reserved area of the disks. The infor-
mation is used by the drive to support various SCSI commands and for the purpose of failure analysis.
The logging is performed at every 1 hour.
11.19 Information Unit Support
The drive supports the information unit of SPI-4 with the following limitations.
!
RDDATA and WRDATA in the SPI command information unit should be zero.
!
The code 100b of Task Attribute in the SPI command information unit is not supported. The code
100b is to request that the task be managed according to the rules for an automatic contingent
allegiance task attribute.
!
The code 40h of Task Management Functions in the SPI command information unit is not supported.
The code 40h is for the task manager shall perform a clear ACA as defined in the CLEAR ACA
message.
!
BIDI DIRECTION in SPI L_Q information unit should be zero.
Ultrastar 146Z10 hard disk drive specifications
214