User manual

Validation Tests
77
The following stress tests are provided:
CPU_HOG
Creates compute-bound processes that execute tight infinite loop. To start
the test, run command file
@[.CPU_HOG] LAUNCH <nprocesses>
CC
Creates subprocesses that repeatedly compile “Hello World” C program,
execute it and purge files in the subprocess private directory. To start the
test, run command file
@[.CC] LAUNCH <nprocesses>
FILE
Creates subprocesses that repeatedly write generated data to a temporary
file on the disk and read it back. This stress test exercises disk susbsystem,
file system and caches. To start the test, run command file
@[.FILE] LAUNCH <nprocesses> RMS [inst-id] [npasses]
or
@[.FILE] LAUNCH <nprocesses> QIO [inst-id] [npasses]
Scratch files are created in a temporary subdirectory of LAUNCH.COM
location.
RMS mode of the test exercises FCP cache, RMS buffering and disk
extent/VIOC cache.
In QIO mode RMS is not involved (except for opening files) and disk IO
bypasses caches via IO$M_NOVCACHE option. Notice that if your goal is to
exercise disk system (such as UQSSP port and its driver) you generally want
to use QIO mode in order to make sure the data is actually read back from
the drive, and not from the extent cache.
You can observe cache hit rate with command
SHOW MEMORY /CACHE / FULL.
It is also possible to disable VIOC cache (even for RMS mode) by booting with
SYSGEN parameter VBN_CACHE_S to 0 (note: this disables the cache
throughout the cluster).
Optional parameter “inst-id” is a string, typically character A to Z, used in