Enabling asynchronous disk I/O

 

 

# 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

 

Values for RS/6000 AIX

SMIT parameter

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

Available

(to be configured at system restart)

 

 

 

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.

40

Adaptive Server Enterprise

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