memx(8)memx(8)Namememx - memory exerciser
/usr/field/memx [ -h ] [ -s ] [ -ofile ] [ -ti ] [ -mj ] [ -pk ]
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 pattern.
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 exer‐
ciser, 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.
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-
-pk The number of processes to spawn (k). The default is 20.
The maximum is also 20.
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 run‐
ning. 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
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 exercisers
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.
The following example tests all of memory by running 20 spawned pro‐
cesses until a or kill -15 pid is received.
The following example runs 10 spawned processes, memory size 500,000
bytes, for 180 minutes in the background.
% /usr/field/memx -t180 -m500000 -p10 &
Guide to System Exercisers