Introduction
The new Skip Y access methods in DMM vs 9.3 allow you to write a data pattern, covering as much of the full LBA range of a drive, while limiting the test to the user-specified time.
To show how this works we will compare this new method with the old method of simply specifying a Write test to run for one hour.
This example will use a 4TB drive which has an average transfer rate of 150 MB/s.
At that speed we can write a maximum of 540GB (150 MB/s X 3600 seconds).
With a Sequential Write test this will write the first 1/8th of the drive
4 TB total LBAs
540 GB at beginning of LBA range
With the new Skip Y access method the same 540 GB of blocks will be written, but they will be spread evenly across the entire LBA range of the drive
4 TB total LBAs
540 GB spread over entire LBA range
In both cases the Write test runs for 1 hour.
But in the case of the Skip Y test the Writes are spread over the entire range of the drive
How to Define the Skip Y Write Test by time
- In DMMs Test Setup tab click on the Test Type Extern. Step
- Fill in the Command Line Parameters box with the time to run (hours=n), a comma, and the data pattern to use. In this case we enter hours=1,pattern=allzeros
- Fill in the External Program Executable box with either writesamesata (for SATA drives) or writesamescsi (for SAS/SCSI/FC drives)
Note: for SATA drives specify writesamesata, for SAS drives specify writesamescsi - Click the Add This Test to Test Sequence button. The Test Sequence box will show the test added like this
Clicking the View Test Sequence Details button will show the test parameters you’ve specified
Data Patterns Available
You may specify any of the following data patterns to be used in the test
- pattern=allzeros
- pattern=allones
- pattern=altzeroandone
- pattern=altoneandzero
- pattern=incrementing
- pattern=decrementing
- pattern=random
- pattern=walkingzeros
- pattern=walkingones
- pattern=alt1and0thenalt0and1
- pattern=alt0and1thenalt1and0
Log File Output
The DMM .log file will show the test parameters and the results of the test
================================================================================
>> SCSI Toolbox32, Version 9. 3. 0 (build) 160819, running on \\WIN-E7QQNS8J6S<<
>> Default Driver: 10, Operating System: Windows 8 / Server 2012<<
>> Number of Drives Under Test: 1 <<
>> Available Memory (in GB): 1.03 <<
>> SN: 0x00100d31 (3377) <<
================================================================================
Test Date: 10/03/2016 14:43:40
Test Pass: 1
Device: 4:3:0 Vendor: ATA, Product: ST4000NM0053-1C1 Serial: Z1Z08LYE, Version: SS03
Capacity: 4,000.79 GB, BlockSize: 512 (0x200)
Results:
10/03/2016 14:43:41 TEST 1 of 1:
External Program Test, executable = writesamesata
Stop-on-Error Type: Stop Current Test
String Data from the External Program follows:
WriteSameSATA Wrote: 858,783,744 Blocks,
Skipped: 6,955,253,424 Blocks,
Percent Written: 10.99%,
Cap: 7,814,037,168 Blocks,
Transfer Rate: 102.88 MB/sec,
Cmd Line Parameters: pattern=walkingones,hours=1.13
10/03/2016 15:51:37 Worker ID: 1
10/03/2016 15:51:37 Test Completed Successfully
10/03/2016 15:51:37 PASSED
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