You might see this behavior when issuing D STOR to see the current Storage usage:
APU2ETPX - ****************** TPX Operator ************************* TEN0217
Storage Statistics (Below 16M line)
Open ACBs: 0342 Total ACBs: 1665 Terminals: 0179 Applications: 0702
DSA Bytes: 04440064 Current Use: 005 % High Use: 006 % Free Areas: 0006
Slot Bytes: 01441600 Current Use: 000 % High Use: 002 % Overflows: 03541
Slot Size * Count = Bytes Curr.Use Max.Use Failed Requests
01 00016 1024 16384 000 % 000 % 0 169363
02 00024 680 16320 000 % 000 % 0 223109
03 00032 1920 61440 000 % 006 % 0 22498
04 00064 2560 163840 001 % 001 % 0 40436
05 00072 1080 77760 000 % 000 % 0 4311
06 00104 2008 208832 000 % 000 % 0 69783
07 00128 928 118784 000 % 000 % 0 15917
08 00512 928 475136 000 % 000 % 0 870202
09 01024 56 57344 000 % 008 % 0 37530
10 02048 40 81920 000 % 010 % 0 247378
11 04096 8 32768 000 % 037 % 0 46869
12 08192 16 131072 000 % 006 % 0 4069
***************************** BOTTOM OF DATA **************************
No single Slot Request failed but there are 3541 Overflows. The answer is that if TPX needs a Slot from Pool 12 but these Slots are to small to fulfill the request the storage is taken from the DSA-Area of TPX and this event is marked as one Overflow. If you for example use TPXMAIL you need Slots of 10240 Bytes length. If Slot 12 contains only 8192 Bates long Slots (see above) no single request for TPXMAIL can be served from Slot 12.
The solution is to use the Slot sizes recommended in the TPX manuals and no smaller ones.
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