Zcom_Mem_Size - HP 9000 Installation And Configuration Manual

Hide thumbs Also See for 9000:

Table of Contents

Tuning and Sizing

ZCOM_MEM_SIZE

The ACC Mux Subsystem reserves a contiguous block of kernel memory

for tables for its use. This block of memory is used for table space and for

data buffering internal to the ACC Mux Subsystem product.

The maximum size of the memory block is set by the value of the

zcom_mem_size parameter in the "system" file used to build your kernel.

Typically, this is the file /stand/system. The default value is 4 M-Byte.

The zcom_mem_size value can be sized to reflect what is actually

required for a given system configuration.

The zcom_mem_size parameter should never be set less than the "Total

Size" value which is reported when ttgen is run using the -s option on the

ttgen configuration file. The algorithm below can be used to estimate a

reasonable value for zcom_mem_size.

In the case that zcom_mem_size is not set to a large enough value for the

given configuration, the program zmasterd will be unable to start up the

ZCOM subsystem. If the zmlog utility is running, a message is placed in

the log file indicating that zmon does not have enough memory to start

up. If zcom_mem_size is large enough to hold the internal tables, but is

not large enough to handle the buffering between the ACC Mux card and

the ACC Mux Subsystem drivers, the subsystem will still function, but

the performance may be degraded.

If zcom_mem_size is not large enough, it is suggested that the ttgen

configuration file be reviewed to make sure that it only contains what is

actually required.

If zcom_mem_size is modified, the kernel must be rebuilt, and the system

rebooted for the change to take effect.

Appendix B

Table of Contents