ASM IOSTAT shows constant writes - normal behavior?

I have 2 disk groups, one with no database, the other with the database shutdown.  Running iostat -t 5 I see:

Group_Name  Dsk_Name         Reads  Writes    Read_Time  Write_Time

DATA2_DG    DATA2_DG_0000    0.00   4096.00   0.00       3.01

DATA2_DG    DATA2_DG_0001    0.00   4096.00   0.00       3.01

DATA_DG_FC  DATA_DG_FC_0000  0.00   4096.00   0.00       3.01

DATA_DG_FC  DATA_DG_FC_0001  0.00   4096.00   0.00       3.01

Nearly consistently (i.e. writing 4K bytes every 5 seconds).  Is this expected behavior?

Doug