Installation guide

If you are installing the secure version of syslogd on a system, and you

have conﬁgured or intend to conﬁgure other hosts to forward syslog

messages to the system, refer to the syslogd(8) and syslog.auth(4)

reference pages.

1.10 Changes to VFS and AdvFS Tunable Attributes

The default value of the Virtual File System (VFS) vfs subsystem attribute

name-cache-hash-size has changed from 256 to a dynamically

calculated value. The new value is name-cache-size divided by 8 and

rounded up to the next power of 2, or 8192, whichever is less.

On systems where the nchsz conﬁguration variable in

/sys/conf/param.c has been modiﬁed by the customer, the customer-

provided value will be used. Compaq recommends that any previous

customization of nchsz in the param.c ﬁle be changed to:

int nchsz;

Compaq also recommends that you use the default dynamic calculation of the

size of the namei cache hash change table.

If a customer speciﬁed value is still desired, Compaq recommends modifying

the value of name-cache-hash-size in /etc/sysconfigtab,

instead of modifying nchsz in /sys/conf/param.c. See

sysconfigdb(8) for more information.

The default value of the AdvFS subsystem attribute AdvfsMaxDevQLen

has changed from 80 to 24 (number of I/O requests). The new default of 24

reduces the number of I/O requests queued to a device. A lower value favors

response time by reducing the number of I/O requests that may be already

queued ahead of synchronous read and write requests.

A new AdvFS subsystem attribute, AdvfsCacheHashSize is added.

AdvfsCacheHashSize determines the size of the hash table for the

buffers of the AdvFS buffer cache. The minimum value is 1024. The

maximum value is 65536.

The default value is the size of the AdvFS buffer cache

(AdvfsCacheMaxPercent) divided by 10 and rounded up to the next

power of 2, or 8192, whichever is less. To save a small amount of space in

the kernel at the expense of longer hash queue search time, the

AdvfsCacheHashSize can be set to a smaller value.

For more information about VFS and AdvFS tuning, refer to the System

Conﬁguration and Tuning guide.

New and Changed Features 1–5