Essential System Administration, 3rd Edition

AIX System Parameters

On AIX systems, you never need to rebuild a kernel because system parameters may be changed on a running system. The current values of AIX system parameters may be displayed with the lsattr command:

# lsattr -EHl sys0                     
             
            Final option letter is a lowercase L.
attribute    value    description                    user_settable
  
keylock      normal   State of system keylock at boot time   False
maxbuf       20       Maximum pages in block I/O BUFFER CACHE True
maxmbuf      2048     Maximum KB real memory allowed for MBUFSTrue
maxuproc     400      Maximum # PROCESSES allowed per user    True
autorestart  false    Automatically REBOOT after a crash      True
iostat       false    Continuously maintain DISK I/O history  True
realmem      65536    Amount of usable physical memory (KB)  False
conslogin    enable   System Console Login                   False
fwversion    IBM,SPH01184   Firmware version,revision levels False
maxpout      0        HIGH water mark pending write I/Os/file True
minpout      0        LOW water mark pending write I/Os/file  True
fullcore     false    Enable full CORE dump                   True
pre430core   false    Use pre-430 style CORE dump             True
ncargs       6        ARG/ENV list size in 4KB blocks         True
rtasversion  1        Open Firmware RTAS version             False
modelname    IBM,7044-270   Machine name                     False
systemid     IBM,011000189  Hardware system identifier       False
boottype     disk     N/A                                    False
SW_dist_intr false    Enable SW distribution of interrupts    True
cpuguard     disable  CPU Guard                               True
frequency    93750000 System Bus Frequency                   False

The list includes parameters that can be modified and ones that can’t. Being able to see, for example, the amount of physical ...