tc and rs

[#1]

What is the difference between tc and rs ?
Thanks

[malay boy]

tc - soft reset
rs - hard reset

Hard Reset

A hard reset is disruptive. It initiates the processor self-test that resets memory and terminates all I/O operations. A hard reset is necessary after a hardware failure or after an error from which the system cannot recover.

A hard reset is initiated when the CPU is powered on. If the system is powered on already, then entering the reset command, RS, at the system console initiates the hard reset process.

Soft Reset

A soft reset, the type of reset used most often, preserves the current processor state. This type of reset performs a nondisruptive memory test and terminates all I/O operations before executing recovery software for starting the boot device and console selection process. A soft reset can also occur during a software reboot at the completion of a bootable ISL utility, such as INSTALL, UPDATE, or DUMP.


Purely cut-paste from the manual.

regards
mB

[Zeev Schultz]

RS : Reset System ***
TC : Reset via Transfer of Control ***

When to use RS?Obviously rare usage,mostly when
you don't want a system to produce a memory crash dump.Cases of hardware fault.

When to use TC (TOC) - system hangs (blocked interupts,endless loops,user application doesn't release cpu on UP computers etc).MC/Service Guard also can generate TOC for
example.In case of hang produce memory (crash) dump.In case of hardware fault (machine check)
doesn't.

Zeev

[#4 · Accepted solution]

A TOC (usually a push button located at back of system or on GSP) (Ctrl-B >TC from console or GSP)
When a TOC is issued a dump will be taken on system reboot. This is opposed to an RS, or reset which will interupt system processing and not dump. (quicker)
TC : System reset through INIT or TOC (Transfer of Control) signal
RS : Reset System through RST signal

[Bill McNAMARA_1]

the TC will create a crash dump in /var/adm/crash

RS won't

You use these when your system is hung for example.
If you want to debug why your system was hanging you use TC to create the crash dump for later analysis.

Some crash dumps can takes hours to complete, depending on the ammount of memory you have, so be prepared to wait!

Later,
Bill