User manual

Miscellaneous Notes
74
disabling thread priority control and eliminating its overhead outweighs the loss of throughput
due to smaller number of processors, i.e. if dedicated host system has large number of LCPUs
and VAX instance executes a workload with very high rate of interlocked instructions.
To disable VAX MP VCPU threads priority control, add the following command to VAX MP
startup script:
DEPOSIT HOST_DEDIDCATED 1
TS vs. TQ
If you intend to make heavy use of tape drive, it is better to use MSCP drive (SIMH TQ device)
rather than TS-11 or TSV-05 (TS device). TQ performs better under multiprocessor load than TS.
For occassional or light use TS is fine.
Boot ROM failures
Very occasionally boot ROM initialization diagnostic may fail with messages like:
sim-cpu0> boot cpu
?C6 2 01 FF 00 0000
P1=00000000 P2=00000000 P3=00000000 P4=00000000 P5=00000000
P6=00000000 P7=00000000 P8=00000000 P9=00000000 P10=00000000
r0=00000080 r1=00000020 r2=00000000 r3=201407A4 r4=2004D2F0
r5=2004D310 r6=2004D312 r7=00000000 r8=00000000 ERF=80000000
KA655X-B V5.3, VMB 2.7
Performing normal system tests.
40..39..38..37..36..35..34..33..32..31..30..29..28..27..26..25..
24..23..22..21..20..19..18..17..16..15..14..13..12..11..10..09..
08..07..06..05..04..03..
Normal operation not possible.
This problem is not specific to VAX MP but occurs with uniprocessor SIMH VAX as well. It is safe
to disregard this message and proceed with booting operating system.
SHOW CLUSTER may intermittently fail when used in native interlock mode
SHOW CLUSTER /CONTINUOUS command has somewhat hidden feature whereby user by
pressing SELECT key is allowed to enter command console mode to add extra infromation
classes to default SHOW CLUSTER display.
When using VAX MP native interlock mode (VSMP LOAD INTERLOCK=NATIVE) this display may
intermittently fail for an update cycle and display question marks in some data fields (such as
queue lengths) instead of values.
Probability of such failure is very low, but it is possible.