MPE/iX 5.5 Operating System Limits

(2) Mounted vol set table - KSO206
The MVST table is created at system boot time during the volume management initiation
process. A new entry is added to the MVST when a master volume is initialized or
mounted on the system. The entry will be added to the first free entry in the table, and all
the fields in entry will be initialized with information about the mounted volume set on
the system. The first entry is MPEXL_SYSTEM_VOLUME_SET. The max number of
entries is 255, which means that the system can theoricaly support 255 different volume
sets.
(3) Mirrored volumes
The maximum number of DISC LDEVs supported is 255, that means that the maximum
number of pairs of mirror disks will be 127 (LDEV 1 can't be mirrored). As a
consequence the maximum disc space avalailable on a system will be half of what is
available without mirror disks. This because a pair of mirror disks uses two ldevs and has
the storage of one.
NOTE: 127 is the absolute maximum number of mirrored pairs, but this leaves only ldev
1 as the entire system volume set. In most cases, this is not practical. All the necessary
transient space for the system must come from the system volume set.
Virtual space management:
Item Limit Description Resource Table
1 ~1973784 Extents for Objects (Fixed Access Rights) Extent B-Tree table
2 64520 Extents for Objects (Var Access Rights) Extent AR B-Tree Tbl
3 91180 File Objects VSOD GUFD Table
4 490637 Objects Allowed (files + transient objs) VSOD+VSOD GUFD Tbl
5 310689 Pages Mapped in Memory (Global A/R) VPN Cache Table
6 310689 Pages Mapped in Memory (Variable A/V) VPN AR Cache Tbl
1 246723 Swappable Objects (Fixed Access Rights) Extent B-Tree tbl
2 8065 Swappable Objects (Var Access Rights) Extent AR B-Tree Tbl
7 399457 Transient Objects Allowed VSOD Table
8 30840 VS B-Tree Entries VS B-Tree Table
9 80659 Virtual Space Domains VS Domain Desc Table