System Debug Reference Manual (32650-90888)

Chapter 13 525
Standalone Analysis Tool (SAT)
How SAT Works
13 Standalone Analysis Tool (SAT)
The Standalone Analysis Tool (SAT) aids support and lab personnel in analyzing MPE/iX
system events such as process hangs, operating system failures, and hardware failures.
How SAT Works
SAT is implemented as a standalone image. You can boot it from ISL. This means you can
analyze system failures as soon as they occur without taking a dump.
Being a bootable utility, SAT runs in the area of memory saved by MMSAVE during the
boot from the primary boot path. SAT directly accesses main memory, the memory save
area on LDEV 1 and virtual storage on the system disks. Like DAT, SAT requires that the
data structures involved in virtual address translation be intact in order to support virtual
addressing.
SAT lets you analyze a failure quickly without going through the dump process. Then, if
you do decide to make a dump tape, exit to ISL and invoke the DUMP utility. The main
memory contents and the data on disk are not altered by SAT.
Operating SAT
Follow these steps to use SAT:
1. First, be sure the system has failed.
2. Use the TC command to restart the failed or hung system through the access port. This
preserves memory.
Do not use the RS command -- it erases memory!
NOTE If SAT is not present on disk and must be booted from tape, ISL must first be
booted from disk so that the MMSAVE utility has a chance to save main
memory to disk. If this step is skipped, SAT is loaded into memory, overlaying
the state of the machine.
The following example shows what a user might see entering TC to transfer control,
then CO to return to console mode.
TIP CM>TC Transfer Control