USER RESPONSIBLE FOR VERIFYING VERSION AND COMPLETENESS
OEM FUNCTIONAL SPECIFICATION ULTRASTAR XP (DFHC) SSA MODELS 1.12/2.25 GB -1.0" HIGH

3.6.5 Save Logs and Pointers

The drive periodically saves data in logs in the reserved area of th e disks. The information is used by the
drive to support various commands and for the purpose of failure analysis.
Logs are saved every 35 minutes. The amount of time it takes to update the logs varies depending o n the
number of errors since the last update. In most cases, updating those logs and th e pointers to those logs will
occur in less than 30 milliseconds.

3.6.6 Disk Sweep

The heads are moved to another area of the disk if the drive has no t received a command for at least 40
seconds. After flying i n the same spot for 9 minutes, the heads are moved to another position. Execution
time is less than 1 full stroke seek.

3.6.7 Summary

Table 10. Summary of Idle Time Function Performance Impacts
3.7 Command Timeout Limits
The 'Command Timeout Limit' is defined as the time period from when the SCSI_command message is
received by the drive until the corresponding SCSI_status message istransmitted by the drive.
The following times are for environments where Automatic Reallocation is disabled and there are no queued
commands.
Reassignment Time:
The drive sh ould be allowed a minimum of 45 seconds to complete a "Reassign
Blocks" command.
Format Time:
The time to complete a "Format Unit" command (with Immed bit = 0) varies by model:
C4x 45 minutes
C2x 25 minutes
C1x 15 minutes
Initiators should also use this time to allow format sequences initiated by "Format Unit" commands (with
Immed bit = 1) to compete and place th e drive in a "ready for use" state.
Start/Stop Unit Time:
The drive shou ld be allowed a minimum of 30 seconds to complete a "Start/Stop
Unit" command (with Immed bit = 0).
Initiators should also use this time to allow start-up sequences initiated by au to start ups and "Start/Stop
Unit" commands (with Immed bit = 1) to complete and place the drive in a "ready for use" state.
Idle Time Function Type Max. Frequency of Occurrence
(minutes) Duration (ms) Mechanism to Delay/Disable
Servo Run Out 60/(trk/cyl) 100 Re-instruction Period
Servo Bias ( < 1sthour) 12 200 Re-instruction Period
Servo Bias ( > 1sthour) 60 200 Re-instruction Period
PFA 30/(trk/cyl) 80 Re-instruction Period / LITF
Channel Calibration 240 64 Re-instruction Period
Save Logs & Pointers 35 30 Re-instruction Period
Note: "Re-instruction Period" isthe time between consecutive SCSI command requests.
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