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Oracle Solaris Tunable Parameters Reference Manual     Oracle Solaris 11 Information Library
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Document Information

Preface

1.  Overview of Oracle Solaris System Tuning

2.  Oracle Solaris Kernel Tunable Parameters

Where to Find Tunable Parameter Information

General Kernel and Memory Parameters

physmem

zfs_arc_min

zfs_arc_max

default_stksize

lwp_default_stksize

logevent_max_q_sz

segkpsize

noexec_user_stack

fsflush and Related Parameters

fsflush

tune_t_fsflushr

autoup

dopageflush

doiflush

Process-Sizing Parameters

maxusers

reserved_procs

pidmax

max_nprocs

maxuprc

ngroups_max

Paging-Related Parameters

lotsfree

desfree

minfree

throttlefree

pageout_reserve

pages_pp_maximum

tune_t_minarmem

fastscan

slowscan

min_percent_cpu

handspreadpages

pages_before_pager

maxpgio

Swapping-Related Parameters

swapfs_reserve

swapfs_minfree

Kernel Memory Allocator

kmem_flags

kmem_stackinfo

General Driver Parameters

moddebug

ddi_msix_alloc_limit

Network Driver Parameters

igb Parameters

mr_enable

intr_force

ixgbe Parameters

tx_queue_number

rx_queue_number

intr_throttling

rx_limit_per_intr

tx_ring_size

rx_ring_size

tx_copy_threshold

rx_copy_threshold

General I/O Parameters

maxphys

rlim_fd_max

rlim_fd_cur

General File System Parameters

ncsize

dnlc_dir_enable

dnlc_dir_min_size

dnlc_dir_max_size

TMPFS Parameters

tmpfs:tmpfs_maxkmem

tmpfs:tmpfs_minfree

Pseudo Terminals

pt_cnt

pt_pctofmem

pt_max_pty

STREAMS Parameters

nstrpush

strmsgsz

strctlsz

System V Message Queues

System V Semaphores

System V Shared Memory

segspt_minfree

Scheduling

disp_rechoose_interval

Timers

hires_tick

timer_max

SPARC System Specific Parameters

consistent_coloring

tsb_alloc_hiwater_factor

default_tsb_size

enable_tsb_rss_sizing

tsb_rss_factor

Locality Group Parameters

lpg_alloc_prefer

lgrp_mem_default_policy

lgrp_mem_pset_aware

3.  NFS Tunable Parameters

4.  Internet Protocol Suite Tunable Parameters

5.  Network Cache and Accelerator Tunable Parameters

6.  System Facility Parameters

A.  Tunable Parameters Change History

B.  Revision History for This Manual

Index

General Driver Parameters

moddebug

Description

When this parameter is enabled, messages about various steps in the module loading process are displayed.

Data Type

Signed integer

Default

0 (messages off)

Range

Here are the most useful values:

  • 0x80000000 – Prints [un] loading... message. For every module loaded, messages such as the following appear on the console and in the /var/adm/messages file:

    Apr 20 17:18:04 neo genunix: [ID 943528 kern.notice] load 'sched/TS_DPTBL' id 15 
    loaded @ 0x7be1b2f8/0x19c8380 size 176/2096
    Apr 20 17:18:04 neo genunix: [ID 131579 kern.notice] installing TS_DPTBL, 
    module id 15.
  • 0x40000000 – Prints detailed error messages. For every module loaded, messages such as the following appear on the console and in the /var/adm/messages file:

    Apr 20 18:30:00 neo unix: Errno = 2
    Apr 20 18:30:00 neo unix: kobj_open: vn_open of /platform/sun4v/kernel/exec/sparcv9/intpexec fails 
    Apr 20 18:30:00 neo unix: Errno = 2
    Apr 20 18:30:00 neo unix: kobj_open: '/kernel/exec/sparcv9/intpexec'
    Apr 20 18:30:00 neo unix:  vp = 60015777600
    Apr 20 18:30:00 neo unix: kobj_close: 0x60015777600
    Apr 20 18:30:00 neo unix: kobj_open: vn_open of /platform/SUNW,Sun-Fire-T200/kernel/exec/sparcv9
    /intpexec fails, 
    Apr 20 18:30:00 neo unix: Errno = 2
    Apr 20 18:30:00 neo unix: kobj_open: vn_open of /platform/sun4v/kernel/exec/sparcv9/intpexec fails
  • 0x20000000 - Prints even more detailed messages. This value doesn't print any additional information beyond what the 0x40000000 flag does during system boot. However, this value does print additional information about releasing the module when the module is unloaded.

These values can be added together to set the final value.

Dynamic?

Yes

Validation

None

When to Change

When a module is either not loading as expected, or the system seems to hang while loading modules. Note that when 0x40000000 is set, system boot is slowed down considerably by the number of messages written to the console.

Commitment Level

Unstable

ddi_msix_alloc_limit

Description

x86 only: This parameter controls the number of Extended Message Signaled Interrupts (MSI-X) that a device instance can allocate. Due to an existing system limitation, the default value is 2. You can increase the number of MSI-X interrupts that a device instance can allocate by increasing the value of this parameter. This parameter can be set either by editing the /etc/system file or by setting it with mdb before the device driver attach occurs.

Data Type

Signed integer

Default

2

Range

1 to 16

Dynamic?

Yes

Validation

None

When to Change

To increase the number of MSI-X interrupts that a device instance can allocate. However, if you increase the number of MSI-X interrupts that a device instance can allocate, adequate interrupts might not be available to satisfy all allocation requests. If this happens, some devices might stop functioning or the system might fail to boot. Reduce the value or remove the parameter in this case.

Commitment Level

Unstable