files in
  1                   restart_0001.nc
                      ...
  ens_size            restart_0002.nc
  PRIOR_INF_MEAN_COPY prior_inflation_mean.nc
  PRIOR_INF_SD_COPY   prior_inflation_sd.nc

files out
  * POSTERIOR *
  1                   restart_out_0001.nc
                      ...
  ens_size            restart_out_0002.nc

  ENS_MEAN_COPY       PostDiag_mean.nc
  ENS_SD_COPY         PostDiag_sd.nc

  POST_INF_MEAN_COPY  PostDiag_inflation_mean.nc
  POST_INF_SD_COPY    PostDiag_inflation_sd.nc

  * PRIOR *
  1                   prior_member_0001.nc
                      ...
  ens_size            prior_member_0002.nc

  ENS_MEAN_COPY       PriorDiag_mean.nc
  ENS_SD_COPY         PriorDiag_sd.nc 
  PRIOR_INF_MEAN_COPY PriorDiag_inflation_mean.nc
  PRIOR_INF_SD_COPY   PriorDiag_inflation_sd.nc
  ** or SPARE_COPY if num_output_state_members > 0

COPIES
   ENS_MEAN_COPY         = ens_size + 1
   ENS_SD_COPY           = ens_size + 2
   PRIOR_INF_COPY        = ens_size + 3
   PRIOR_INF_SD_COPY     = ens_size + 4
   POST_INF_COPY         = ens_size + 5
   POST_INF_SD_COPY      = ens_size + 6

   SPARE_COPY_MEAN       = ens_size + 7
   SPARE_COPY_SPREAD     = ens_size + 8
   SPARE_COPY_INF_MEAN   = ens_size + 9
   SPARE_COPY_INF_SPREAD = ens_size + 10

current namelist options
   WRITE
   - output_inflation
   - output_restart
   - output_restart_mean
   - num_output_state_members > 0 -> spare_copies = .false.
     
   READ
   - mean_from_restart
   - sd_from_restart

THOUGHTS
  - have standard group of file for restarts, inflation and diagnostic
     * if multiple domains have standard _d0X appended before .nc
  - filenames are directly connected to COPIES #, feed these into filenames
    or should filenames have inherent knowledge
  - query_write_copy(my_copy - recv_start + 1)
    restart_files_out(my_copy - recv_start + 1)
  - write, read loop go 1, num_copies
     * 
