The onstat -g rbm Option

The onstat -g rbm option prints block bit map for the resident segment (communication message area).
Example Output
Figure 82. onstat -g rbm Output
IBM Informix Dynamic Server Version 10.00.UC1 -- On-Line -- Up 01:59:23 -- 101376 Kbytes
Block bitmap for resident segment address 0xa000000:
 address = 0xa000290, size(bits) = 4863
 used = 4820, largest_free = -1
 firstfree = 1, lastalloc=4820
      0:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
    256:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
    512:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
    768:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   1024:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   1280:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   1536:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   1792:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   2048:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   2304:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   2560:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   2816:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   3072:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   3328:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   3584:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff 
   3840:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
   4096:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
   4352:ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
   4608:ffffffffffffffff ffffffffffffffff ffffffffffffffff fffff00000000000