I tested the process quoted by you. It worked fine but the problem is now I can also insert data into read only files.

select name,is_read_only from sys.filegroups

PRIMARY 0

FGDayRange011

FGDayRange021

FGDayRange031

FGDayRange041

FGDayRange050

FGDayRange060

Before Inserts:

total records Partitionnumber

450 3

550 6

50 1

450 4

500 5

450 2

After Inserts:

Total RecordsPartition Number

500 3

600 6

50 1

500 4

550 5

500 2

Currently the clustered primary index is created on file group FGDayRange06. I am using the below query to get the total count---

SELECT COUNT(*) AS [Total Records], $Partition.pfFiveDayRange(businessDate) AS [Partition Number]

FROM MSSQLTIPS_Partitions

GROUP BY $Partition.pfFiveDayRange(businessDate);

I am completely bowled by the above scenario. What I am missing? Any suggestions?