MPE/iX 5.5 Operating System Limits

Using 90 libraries plus the program file, or 91 executable files, and assuming 10,000
shared global data exports, we can calculate the average number of data imports per data
export before exhausting all the space available in the PFL object.
PFL chain length = 100 + 91 * (184 + 32 * 500)
= 1,472,844 bytes
PDD size = 96 + 16,000 + 10,000 * (84 + 24 * L)
= 856,096 + 240,000 * L
1,472,844 + (856,096 + 240,000 * L) <= 20,971,520
L <= 75 average data imports per data export
From this calculation, the PFL contains a maximum of 91 executable files with 10,000
shared global data exports with an average of 75 data imports per data export. But, any
combination of values for the listed items may be used as long as they satisfy the limits
outlined above.
Label management:
Item Limit Description Resource Table
1 262144 Entries in Label Table Label Table
(1) Label table
There is one label table for each volume on the system. The Label table exits on disc and
it is mapped into a virtual space when the volume is mounted. The label table contains for
each file on a volume the LABEL itself and the extent descriptors of the file (each extent
block describes up to 20 extents of the file and there is no theorical limit for the number
of extent descriptors of a file.)
The label table is managed by the Table Management. Each table entry is three sectors.
With the introduction of Cascade Disk Array, the capacity of a disk volume was
increased. That's why the maximum number of entries per label table was increased from
32,768 in MPE/iX 3.0 to 262,144 in MPE/iX 4.0. The table's maximum size is
201,326,592 bytes. The initial allocation of the table is 790,528 bytes and the increment
size is 786,432 bytes.
Misc: