To switch from 32bit to 64bit kernels:
Performance improvement for FASTt
This info is generally applicable to AIX systems using FAStT storage and is thought to improve performance. Some of these may be outdated, investigate before using.
Find which processes are using the most memory
If you need to find out which processes are hogging all the RAM, run:
ps -Ao vsz,pid,args | sort -nr | head -n 20AIO servers
If applications use asynchronous I/O on filesystem files, the OS uses the AIO subsystem. The number of AIO servers to start per CPU and the number of requests each server fills can be tuned with the smit fastpath “aio”. I usually set the number of request to 8192.
Misc. network commands
Just a collection of semi-usefull commands.
Lookup SRV records with nslookup
Lots of new software is starting to use SRV records in bind 8+. nslookup has a hard time looking up the records, because most SRV records have unusual character combinations.
Resetting MTU size
If the MTU size on all nodes in a HACMP cluster do not match, the cluster will NOT start. Check with “netstat -i”.
Removing an IP alias
On AIX 4.3+, IP aliases are stored in the ODM, this is much better than hacking the /etc/rc.net script. Removing the IP alias from the ODM isn’t quite so obvious.
Restoring a single file from a mksysb
Sometimes you want to just restore a single file from a mksysb:
Creating a ram disk on AIX
Sometimes using a RAM disk makes sense. I haven’t tested these commands with a recent OS, but here are the steps. Run the following commands to setup a Ram Disk, the disk will not be recreated after bootup: