AIX 7.2 System Administration
AIX 7.2 administration is examined here as one open-ended domain: the blueprint enumerates no subtopics, so questions can come from any part of day-two operations - LVM and JFS2 storage, boot and init, error logging and SRC, the /etc/security files, and PowerVM-aware jobs such as mksysb and WPAR. Expect command-level recall plus "what happens next" reasoning.
Know the stack and where its state lives
Physical volumes feed volume groups, which are carved into logical volumes, which carry JFS2 filesystems. The ODM (/etc/objrepos) is authoritative for device and VG configuration, and a VGDA copy is written to each PV. Filesystem mount stanzas live in /etc/filesystems, not /etc/fstab. Probes worth memorising: lspv (PV to VG), lsvg -p vg (free PPs per disk), lslv -m lv (LP to PP map, one column per copy), df -g.
Boot, init, and services
bootlist -m normal -o prints the boot order; rerun bosboot only when the boot image itself changed. /etc/inittab entries invoke rc scripts, while long-running daemons belong under the SRC (lssrc -a, startsrc -s). Boot messages land in the alog bootlog, not in errpt.
Worked example
Task: grow /var by 2 GB on a mirrored rootvg. lsvg -p rootvg shows 600 free PPs on hdisk0 but only 20 on hdisk1. Because the LV has two copies, each copy needs its own PPs, and lslv -m shows /var currently sits entirely on hdisk0. The chfs -a size=+2G /var call fails because AIX cannot place the second copy's PPs on a full disk. Fix: free PPs on hdisk1, then rerun the same chfs. Note that size=+2G is relative growth whereas size=2G sets an absolute size.
Traps that cost marks
Shrinking works on JFS2 only when free space sits at the end of the LV, and JFS never shrinks. errpt -a decodes detail while errclear ages entries out of /var/adm/ras/errlog. A chfs value with no leading + or - is absolute, not incremental. mksysb captures rootvg only.