memx(8) System Manager's Manual memx(8)
Name
memx - memory exerciser
Syntax
/usr/field/memx [ -h ] [ -s ] [ -ofile ] [ -ti ] [ -mj ] [ -pk ]
Description
The memory exerciser spawns processes to exercise memory by writing and reading three patterns: 1's and 0's, 0's and 1's, and a random pat-
tern.
You specify the number of processes to spawn and the size of memory to be tested by each process. The first process is a shared memory
exerciser, the remaining are standard memory exercisers. The exerciser will run until the process receives a or a kill -15 pid.
A logfile is made in for you to examine and then remove. If there are errors in the logfile, check the file, where the driver and kernel
error messages are saved.
Options
The options are:
-h Print the help message for the command.
-s Disable shared memory testing.
-ofile Save diagnostic output in file.
-ti Run time in minutes (i). The default is to run until the process receives a or a kill -15 pid.
-mj The memory size in bytes (j) to be tested by each spawned process. Must be greater than 4095. The default is (total-memory)/20.
-pk The number of processes to spawn (k). The default is 20. The maximum is also 20.
Restrictions
The exerciser is restricted by the size of swap space available. The size of the swap space and the size of internal memory available will
determine how many processes can run on the system. For example, If there were 16Mbytes of swap space and 16Mbytes of memory, all of the
swap space would be used if all 20 spawned memory exercisers were running. In that event, no new processes would be able to run. On sys-
tems with large amounts of memory and small swap space, you must restrict the number of memory exercisers and/or the size of memory being
tested.
If there is a need to run a system exerciser over an NFS link or on a diskless system there are some restrictions. For exercisers that
need to write into a file system, such as the target file system must be writable by root. Also the directory, in which any of the exer-
cisers are executed, must be writable by root because temporary files are written into the current directory. These latter restrictions
are sometimes difficult to overcome because often NFS file systems are mounted in a way that prevents root from writing into them. Some of
the restrictions may be overcome by copying the exerciser to another directory and then executing it.
Examples
The following example tests all of memory by running 20 spawned processes until a or kill -15 pid is received.
% /usr/field/memx
The following example runs 10 spawned processes, memory size 500,000 bytes, for 180 minutes in the background.
% /usr/field/memx -t180 -m500000 -p10 &
See Also
Guide to System Exercisers
memx(8)
