IBM C4C 4.51 3.5-inch Small FF 38-pin Unitized Command Timeout Limits, Save Logs and Pointers

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U S E R RESPONSIBLE F O R V E R I F Y I N G VERSION A N D COMPLETENESS

O E M F U N C T I O N A L S P E C I F I C A T I O N U L T R A S T A R X P ( D F H C ) SSA M O D E L S 1.12/2.25 G B - 1.0" H I G H

3.6.5 Save Logs and Pointers

The drive periodically saves data in logs in the reserved area of the 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 on the number of errors since the last update. In most cases, updating those logs and the 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 not received a command for at least 40 seconds. After flying in 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

 

 

 

 

 

 

 

Idle Time Function Type

Max. Frequency of Occurrence

Duration (ms)

Mechanism to Delay/Disable

 

 

 

(minutes)

 

 

 

 

 

 

 

 

Servo R u n Out

60/(trk/cyl)

100

Re-instruction Period

 

 

 

 

 

Servo Bias ( <

1st hour)

12

200

Re-instruction Period

 

 

 

 

 

Servo Bias ( >

1st hour)

60

200

Re-instruction Period

 

 

 

 

 

 

 

P F A

 

30/(trk/cyl)

80

Re-instruction Period / L I T F

 

 

 

 

 

 

Channel Calibration

240

64

Re-instruction Period

 

 

 

 

Save Logs & Pointers

35

30

Re-instruction Period

 

 

 

 

 

Note:

"Re-instruction Period" is the time between consecutive SCSI command requests.

 

 

 

 

 

 

 

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 is transmitted by the drive.

The following times are for environments where Automatic Reallocation is disabled and there are no queued commands.

Reassignment Time: The drive should 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 the drive in a "ready for use" state.

Start/Stop Unit Time: The drive should 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 auto start ups and "Start/Stop Unit" commands (with Immed bit = 1) to complete and place the drive in a "ready for use" state.

Source filename=PERFORM

I B M Corporation

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Contents Form Factor Disk Drive Version BM Corporation Preface Source filename=STSSHEXT When Operating Limits ReliabilityContaminants Acoustic Levels Source filename=STSSHEXT General Features FeaturesInterface Controller Features DescriptionModels Reliability FeaturesGeneral SpecificationsSectors/logical block sct/lba User bytes/sector ub/sctUser bytes/logical block ub/lba Sectors/track sct/trkFor Each Notch Capacity EquationsFor Entire Drive 1 C1x Models Power Requirements by ModelInput Voltage + 5 Volts Supply + 1 2 Volts SupplyExample 3. Power Calculation Power Calculation ExamplesExample 1. Calculate the mean 12 volt average current Example 4. Calculate the 12 volt peak current Things to check when measuring 12 V supply currentVolt current during read/write operations C1x Models Typical 12 volt current C1x Models Typical 12 volt spin-up current C1x Models 2 C2x Models Power Calculation Examples Example 4. Calculate the 12 volt peak current Volt current during read/write operations C2x Models Typical 12 volt current C2x Models Typical 12 volt spin-up current C2x Models 3 C4x Models Power Calculation Examples Example 4. Calculate the 12 volt peak current Volt current during read/write operations C4x Models Typical 12 volt current C4x Models Typical 12 volt spin-up current C4x Models CxB Models Power supply methods4.2 DC/DC Converter Hot plug/unplug support Grounding Requirements of the Disk EnclosureM Corporation Event Nominal Maximum Bring-up Sequence and Stop TimesBring-up Sequence Times and Stop Time for C2x Models Source filename=PERFORM Environment Definition PerformanceWorkload Definition # of segments Ub/lba +Sequential Command Execution TimeRandom Basic Component DescriptionsData Transfer to/from Disk Data Transfer to/from SSA Link CommentsTheoretical Data Sector Transfer Rate Approximating Performance for Different EnvironmentsWhen Write Caching is Enabled When Read Caching is EnabledWhen Adaptive Caching is Enabled When Read-ahead is EnabledFor Queued Commands When No Seek is RequiredReordered Commands Back-To-Back CommandsCylinder to Cylinder Skew SkewTrack to Track Skew Idle Time Functions Servo Bias Measurements Servo Run Out MeasurementsPredictive Failure Analysis Channel CalibrationSave Logs and Pointers Command Timeout LimitsDisk Sweep M Corporation Mechanical Weight and DimensionsSmall Form Factor Models CxC ClearancesDimensions are in millimeters Location of Side Mounting Holes of C4C Models Source filename=MECHANIC Unitized Connector Locations Source filename=MECHANIC Carrier Models CxB Dimensions CxB Models M Corporation Handle Docking and Ejection System Auto-docking Assembly Side Rails Side Rail Positioning E D Locations front view CxB Models M Corporation Electrical Connector and Indicator LocationsElectrical Interface SSA Unitized ConnectorPin Carrier ConnectorRow Option Pins and Indicators SSA Link Electrical CharacteristicsSSA Link Cable Device Fault Pin/Indicator Option Port Pin Device Activity Pin/Indicator Option Port PinWrite Protect Option Port Pin Ground long Option Port PinEarly Power Off Warning or Power Fail Power Port Pin Front Jumper Connector12 12V Charge and 5V Charge Power Port pin 1 Programmable pin 1 Option Port PinSpindle Synchronization Over Sync Hard-wire M Corporation Source filename=RELIABLE Seek Error Rate Error DetectionPower On Hours Examples ReliabilityUseful Life Power on/off cyclesMaximum on/off cycles Product LifeMean Time Between Failure *MTBF Install Defect FreeSpql Shipped product quality level Sample Failure Rate ProjectionsConnector Insertion Cycles Periodic MaintenanceInstall Defect Free percentage Percent ESD ProtectionOperating Limits Temperature Measurement PointsP F E T Maximum ReliabilityVibration and Shock Temperature Measurement Points for all Models bottom viewOutput Vibration Limits Drive Mounting GuidelinesOperating Vibration V4S Nonoperating VibrationOperating Shock ContaminantsNonoperating Shock Acoustic Levels Upper Limit Sound Power Requirements Bels for C4x ModelsSource filename=STANDARD Standards SafetyElectromagnetic Compatibility EMC M Corporation Serial Storage Architecture S S a P H Transport Bibliography
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