Sybase DC35823-01-1500-04 User Manual

Page 56

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Enabling asynchronous disk I/O

40

Adaptive Server Enterprise

# ls /dev/asyn*

idev/async /dev/asyncdsk

For IBM AIX

Enable asynchronous disk I/O.

This step is mandatory for IBM users.

Enable asynchronous I/O by adjusting the kernel parameters, using the System
Management Interface Tool (SMIT):

1

Enter “smit” at the UNIX prompt.

2

From the Devices menu, select Asynchronous I/O.

3

Select Change/Show Characteristics of Asynchronous I/O.

4

Enter the values from Table 3-2:

Table 3-2: SMIT parameters for asynchronous I/O

If your system uses more than seven disks at the same time for Asynchronous
I/O, increase the MAXIMUM number of servers value by 1 for every active
device.

Note

Setting the minor device number on /dev/async to 4 reduces or eliminates

transient 605 errors in Adaptive Server.

If you are using LVM mirroring, set the minor device number to 0x0.

SMIT parameter

Values for RS/6000 AIX
4.3.3

MINIMUM number of servers

1

MAXIMUM number of servers

10

MAXIMUM number of REQUESTS I/O

4096

Server PRIORITY

39

ASYNC I/O STATE
(to be configured at system restart)

Available

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