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