If you've already added it to the array, no. It is no longer pre-cleared as unRAID has written to it.
If you had not yet assigned it to the array, then it is simple to change the partitioning using the -C option in preclear_disk.sh
However, it is perfectly fine as you have it. The ONLY drives with the performance issue are Western Digital EARS drives. They have firmware that works less efficiently if not aligned on a 4K boundry. No other drives have this issue.
Please post the preclear report for that drive. you'll find it in /boot/preclear_reports I'll be curious to what it says.
Good to know! Thanks so much for your help Joe. Attached below is the report. Drive was freshly unboxed/installed and not attached to anything else prior. Its condition should be A1.
========================================================================1.13
== invoked as: ./preclear_disk.sh /dev/sdb
== ST2000DL003-9VT166 5YD1VH8Y
== Disk /dev/sdb has been successfully precleared
== with a starting sector of 63
== Ran 1 cycle
==
== Using :Read block size = 8225280 Bytes
== Last Cycle's Pre Read Time : 5:58:20 (93 MB/s)
== Last Cycle's Zeroing time : 7:12:26 (77 MB/s)
== Last Cycle's Post Read Time : 12:11:59 (45 MB/s)
== Last Cycle's Total Time : 25:23:48
==
== Total Elapsed Time 25:23:48
==
== Disk Start Temperature: 23C
==
== Current Disk Temperature: 26C,
==
============================================================================
** Changed attributes in files: /tmp/smart_start_sdb /tmp/smart_finish_sdb
ATTRIBUTE NEW_VAL OLD_VAL FAILURE_THRESHOLD STATUS RAW_VALUE
Raw_Read_Error_Rate = 116 100 6 ok 116989000
Seek_Error_Rate = 60 100 30 ok 1252314
Spin_Retry_Count = 100 100 97 near_thresh 0
End-to-End_Error = 100 100 99 near_thresh 0
Airflow_Temperature_Cel = 74 77 45 ok 26
Temperature_Celsius = 26 23 0 ok 26
Hardware_ECC_Recovered = 36 100 0 ok 116989000
No SMART attributes are FAILING_NOW
0 sectors were pending re-allocation before the start of the preclear.
0 sectors were pending re-allocation after pre-read in cycle 1 of 1.
0 sectors were pending re-allocation after zero of disk in cycle 1 of 1.
0 sectors are pending re-allocation at the end of the preclear,
the number of sectors pending re-allocation did not change.
0 sectors had been re-allocated before the start of the preclear.
0 sectors are re-allocated at the end of the preclear,
the number of sectors re-allocated did not change.
============================================================================