SCO Doctor User Guide

Chapter 2, Views

Tunable Parameters View

There are two Tunable Parameters Views, one for SCO Release 3 systems and one for SCO OpenServer Release 5 systems.

Tunable Parameters View for SCO Release 3

Select View, Tunable Parameters.

Tunable Parameter View - SCO Release 3 Systems

Function:

To display the current configuration of tunable parameters.

Description:

Applicable to SCO UNIX System V/386 Release 3.2.x and SCO Open Desktop/Open Server Release 3.
This view displays a table showing the key operating system tunable parameters, their configured allocation and their current usage. Tunable parameters are data structures within the operating system that may be modified according to the size and load of your computer system. For example, NPROC is the tunable parameter that specifies the number of processes the system can support at any one time. It is vital that the system not exhaust any of these tunable parameters. However, you also do not want to waste memory by allocating resources that are not needed.
The ideal column is used by SCO Doctor's tuning facility. See Chapter 5, ``Tuning'' for more information.

The following parameters are profiled:

nstream - Number of streams structures.

nqueue - Number of streams queues.

nblk4096 - Number of streams 4K blocks.

nblk2048 - Number of streams 2K blocks.

nblk1024 - Number of streams 1K blocks.

nblk512 - Number of streams 512 byte blocks.

nblk256 - Number of streams 256 byte blocks.

nblk128 - Number of streams 128 byte blocks.

nblk64 - Number of streams 64 byte blocks.

nblk16 - Number of streams 16 byte blocks.

nblk4 - Number of streams 4 byte blocks.

nfile - Number of open files.

ninode - Number of open files (unique files).

nproc - Number of processes.

nregion - Number of memory regions.

ncall - Number of callout structures.

nclist - Number of lists.

flckrec - Number of record lock structures.

nfile - Reflects the number of files that can be opened by processes. If two programs open the same file, two file structures will be opened whereas only one inode structure will be created.

nregion - Represents the number of memory regions that the operating system can handle. It is normally a function of the number of processes and should be set to be at least three times the number of processes.

SCO Doctor provides a standard alert and action program that monitors tunable parameter levels. If a resource nears depletion, the Tunable Alert will be triggered. If you approve an increase, the action program will then reconfigure the operating system to increase the default allocation. See Chapter 3, ``Alerts'' and Chapter 4, ``Action Programs'' for further information.

Tunable Parameters View for SCO OpenServer Release 5

Select View, Tunable Parameters.

Tunable Parameter View - SCO OpenServer Release 5

Function:

To display the current configuration of tunable parameters.

Description:

Applicable to SCO OpenServer Release 5.
This view displays a table showing the key operating system tunable parameters, their configured allocation, current usage, maximum and minimum values and their type, which is either dynamic or static. Tunable parameters are data structures within the operating system that may be modified according to the size and load of your computer system.
In SCO OpenServer Release 5, most of these are dynamic meaning they grow automatically as required. They will, however, only grow to a maximum size which is specified in the Limit column of this table. For example, NPROC size may be 83, which means that the operating system has room for 83 processes in the process table. The Inuse column tells you how many process slots are currently in use. Maxuse tells you the maximum number of slots that have been used at any one time. If you start to create more process and require more than 83 slots, the table will grow dynamically as required to Limit in size.
These tables do not shrink. For example, if for a time you had 1000 processes running then went back to your usual 100 processes, you would have 900 process table slots unused.
The ideal column is used by SCO Doctor's tuning facility. See Chapter 5, ``Tuning'' for more information.

The following parameters are profiled:

nbuf - Number of I/O buffers.

nhbuf - Number of buffer headers.

nstream - Number of streams structures.

nqueue - Number of streams queues.

nstr_headers - Number of streams data block headers

nblk524288 - Number of streams 512K blocks.

nblk262144 - Number of streams 256K blocks.

nblk131672 - Number of streams 128K blocks.

nblk65536 - Number of streams 64K blocks.

mblk32768 - Number of streams 32K blocks.

nblk16384 - Number of streams16K blocks.

nblk8192 - Number of streams 8K blocks.

nblk4096 - Number of streams 4K blocks.

nblk2048 - Number of streams 2K blocks.

nblk1024 - Number of streams 1K blocks.

nblk512 - Number of streams 512 byte blocks.

nblk256 - Number of streams 256 byte blocks.

nblk128 - Number of streams 128 byte blocks.

nblk64 - Number of streams 64 byte blocks.

max_inode - Number of open files (unique files).

max_proc - Number of processes.

nclist - Number of lists.

max_flckrec - Number of record lock structures.

max_file - Reflects the number of files that can be opened by processes. If two programs open the same file, two file structures will be opened whereas only one inode structure will be created.

max_region - Represents the number of memory regions that the operating system can handle. It is normally a function of the number of processes and should be set to be at least three times the number of processes.