Quick Reference Administering AIX V5.2 version 1.0 ROOTVG.NET does not warrant that the contents of this QuickRef will meet your requirements or that the exampes are error-free. The QuickRef could include technical inaccuracies or typographical errors. Also read the disclaimer. ROOTVG.NET may make improvements/changes in this QuickRef at any time. © 2003 ROOTVG.NET, All Rights Reserved. For several commands you must have root authority. Click here to use the navigation menu on the left to go to a specific section directly.

System installation and maintenance management

oslevel	Reports the latest installed maintenance level of the system. oslevel -r : determines the highest recommended maintenance level reached for the current version of AIX. oslevel -lr 5100-04: lists which fileset updates are missing if after installing ML 04 on 5100-03 the command oslevel -r still shows 5100-03.
alog	Creates and maintains fixed-size log files. alog -o -t boot : view the boot log (the log that holds boot information). alog -L : lists the logs defined in the alog database.
errpt	Generates a report of logged errors in the system error log. errpt -a : displays a complete detailed report. errpt -c > /dev/console : formats and displays each of the errors at logtime (concurrent error logging) on /dev/console.
errdemon	Starts the error logging daemon errdemon that reads error records from the /dev/error file and creates error log entries in the default system error log /var/adm/ras/errlog. /usr/lib/errdemon : starts the error logging daemon. /usr/lib/errdemon -l : displays the path to the system error log file and error log size. /usr/lib/errdemon -s 2000000 : changes the maximum size of the error log file to 2 MB.
syslogd	The syslogd daemon logs messages from kernel, daemons and system applications using /etc/syslog.conf. *.debug          errlog (add this line to to syslog.conf to redirect all syslog messages to the system error log). stopsrc -s syslogd : stops the syslogd daemon. startsrc -s syslogd : starts the syslogd daemon. refresh -s syslogd : refreshes the syslogd daemon.
errlogger	Logs an operator message. errlogger new disk added on scsi1 adapter : logs "new disk added on scsi1 adapter" in the system error log.
errclear	Deletes entries from the system error log. Software and operator errors (older than 30 days) and hardware errors (older than 90 days) are removed using crontab.
errinstall	Installs or replaces messages in the error logging message sets of the error log message catalog.
errupdate	Updates the Error Record Template Repository (default file /var/adm/ras/errtmplt).
diag	Menu driven program to run a wide choice of tasks and service aids (diagnostics, hardware error report, format, microcode and bootlist management,  ...). Diagnostics modes: Concurrent mode: diag is used during normal operation (only devices not in use can be tested). Single-user mode: run diag after shutdown -m. Stand-alone mode: boot from Diagnostics CD (press F5 when acoustic beep is heard) or boot and press F6 when acoustic beep is heard to load diag from hard disk. if diag returns "diag is not supported on this model" use: SMS mode: boot and press F1 when acoustic beep is heard, select "test the computer". Some older models use a SMS diskette.
alt_disk_install	Installs an alternate disk with a mksysb install image or clones the currently running system to an alternate disk. Note: install bos.alt_disk_install fileset to use alt_disk_install. alt_disk_install -C hdisk2 : Clones the current rootvg to hdisk2. alt_disk_install -C -b update_all -l /dev/cd0 hdisk4 : Creates clone of the current rootvg on hdisk4, installs a ML on the clone and changes the bootlist to hdisk4. alt_disk_install -X old_rootvg : Removes the original rootvg from the ODM, after booting from the new alternate disk (you can still reboot from old_rootvg).
nimadm	Performs Alternate Disk Migration (to a new version or release) of AIX using NIM resources. nimadm -c aix1 -s spot2 -l lpp2 -d "hdisk1 hdisk2" -Y : migrates totarget NIM client aix1, using NIM SPOT resource spot2, the NIM lpp_source lpp2, and hdisk1 and hdisk2 target disks, and agreeing to all required software license agreements for the software being installed (-Y). nim -o alt_disk_install -a source=rootvg -a disk='hdisk2' -a phase=12 holland : clones a rootvg on client holland to hdisk1, but only run phase1 and phase2 (leaving the /alt_inst file systems mounted).

Problem determination

sysdumpdev	Changes the primary or secondary dump device designation in a running system. The default primary dump device is LV /dev/hd6 and the default secondary dump device is /dev/sysdumpnull. A dedicated primary dump device LV /dev/lg_dumplv is created (if sufficient disk space is available) in systems with at least 4 Gigabytes of real memory. sysdumpdev -l : displays current dump device settings. sysdumpdev -P -p /dev/hd7 : changes the primary dump device permanently from the default to LV /dev/hd7. sysdumpdev -e : estimates the dump size (in bytes) for the current running system. sysdumpdev -L : displays statistical information about the last dump. chdev -l sys0 -a autostart=true : automatically reboot after a crash (default is false).
dumpcheck	Checks the disk resources used by the system dump and logs in the system error log. Run default by cron at 3:00 pm local time each day. /usr/lib/ras/dumpcheck -p : requests a dumpcheck. The result is printed to stdout (-p). /usr/lib/ras/dumpcheck -r : discontinues running dumpcheck (removes the crontab entry).
kdb	Displays system images for examining a dump. kdb /var/adm/ras/vmcore.0 /unix : starts kdb using the uncompressed dump file /var/adm/ras/vmcore.0 and kernel file /unix.
snap	Gathers system configuration information and compresses the information into a pax file. snap -a -o /dev/rmt0 : gathers all system configuration information (needs approximately 8 MB space in directory /tmp/ibmsupt) and creates a compressed pax image (snap.pax.Z) of directory /tmp/ibmsupt.
snapcore	Gathers the core file, program, and libraries used by a program to directory /tmp/snapcore (default) and compresses the information into a pax image. The collected information allows debugging and resolving problems within an application. snapcore -d /tmp/snapcore2 core.xx : gathers all needed information for core dump file core.xx and writes it to directory /tmp/snapcore2/snapcore_32811.pax.Z, where 32811 is the process id ($pid) of the snapcore command. uncompress -c snapcore_32811.pax.Z | pax : displays the contents of the pax archive.
check_core	Used by snapcore to gather all information about a core dump. The bos.rte.serv_aid fileset must be installed. /usr/lib/ras/check_core core.xx : displays a list containing the program that caused core dump core.xx and the used libraries.
shconf	Manages the system hang detection parameters for the system hang daemon shdaemon. shconf -d : displays if priority problem detection and lost I/O detection are enabled or not. shconf -E -l prio -H : displays the current shdaemon settings.

System initialization and boot management The numeric 1 key (F1 on graphical display), when pressed during POST (double beep), starts the SMS interface. The numeric 5 key (F5 on graphical display), when pressed during POST, initiates a system boot in service mode using the default service mode boot list. Sequence: 1. diskette (if installed), 2. CD-ROM (if installed), 3. hard disk, 4. tape drive (if installed), 5. network (a. Token ring, b. Ethernet). The numeric 6 key (F6 on graphical display) works like the numeric 5 key, but uses the customized service mode bootlist. This is the preferred method of loading AIX diagnostics from the boot hard disk.

ipl_varyon *	Used to vary on the root volume group during system boot processing. ipl_varyon -i : Inquiry mode - skips ipl device processing. Checks which disks are already bootable.
bosboot	Creates boot image. It does not update the bootlist in the NVRAM. bosboot -a -d /dev/hdisk0 : Re-create boot image on hdisk0. bosboot -a -d /dev/ipldevice -D : creates a boot image with the KDB debugger enabled.
mklv	Creates a logical volume. mklv -y hd5 -t boot rootvg 1 : re-create boot LV (BLV) hd5.
lslv	Displays information about a logical volume. lslv -l hd5 : determines the boot disk.
mkboot	Creates the boot image, the boot record, and the service record. mkboot -c -d /dev/hdisk0 : clears the boot record of PV hdisk0.
chpv	Changes the characteristics of a physical volume in a volume group. chpv -c hdisk1 : clears the boot record of PV hdisk1.
bootinfo	Determines and displays various boot information, including boot device type and boot device name (NOT supported in AIX 4.2 or later). bootinfo -b : returns the last boot device. bootinfo -B hdisk0 : returns 1 if disk is bootable, 0 if not.
bootlist	Displays or alters the list or ordering of boot devices available to the system. Normal boot list: possible boot devices for normal mode. Service boot list: possible boot devices for service mode. Previous boot device: last device from which the system booted. Support of these boot lists is model dependent. bootlist -m normal -o : displays the normal boot list. bootlist -m service -o : displays the service boot list (if available). bootlist -m normal cd0 hdisk0 hdisk1 : makes changes to the normal boot list. bootlist -m prevboot : invalidates the last device from which the system booted.
halt or fasthalt	Writes data to disk (sync) and then stops the system. The system does not restart. Do not use this command if other users are logged into the system.
reboot or fastboot	Restarts the system. Can be used if no other users are logged into the system.
shutdown	Halts the operating system. Checks the existence of the executable /etc/rc.shutdown file (added by the administrator) that specifies all the applications and other user processes to close down. By default the shutdown command powers down the system (if supported and issued). shutdown -Fr : fast system shutdown and restart. shutdown -m +1 : brings the system down to maintenance (single user) mode after waiting one minute. shutdown -l : logs the output during the shutdown to /etc/shutdown.log.
last	Displays information about previous logins using the /var/adm/wtmp file. last reboot : displays the time between reboots. last shutdown : lists last shutdowns of the system.
uptime	Shows how long the system has been up. uptime : displays the current time, the length of time the system has been up, the number of users online, and the load average.
sync	Updates the i-node table and writes buffered files to the hard disk. sync;sync;sync;reboot : writes everything from the buffer to the hard disk and reboots the system.
lsfont	Lists the fonts available for use by the display.
chfont	Changes the default font selected at boot time.
mkfont	Adds the font code associated with a display to the system.
mkfontdir	Creates a fonts.dir file from a directory of font files.
chlang	Sets LANG environment variable in the /etc/environment file for next login.
chtz	Changes the system time zone information in the /etc/environment file.
chhwkbd	Changes the low-function terminal (LFT) keyboard attributes stored in the Object Data Manager (ODM) database.
lskbd	Lists the keyboard maps currently available to the low-function terminal (LFT) subsystem.
chkbd	Changes the default keyboard map used by the low-function terminal (LFT) at system startup.
chkey	Changes your encryption key.
lslicense	Displays the number of fixed licenses and the status of floating licensing. There are two types of user licensing, fixed and floating. Fixed licensing is always enabled. Floating licensing can be enabled or disabled. lslicense -A : displays the number of available fixed licences on the system.
chlicense	Changes the number of fixed licenses and the status of the floating licensing (updates login.cfg). chlicense -I -u 50I -u 50 : changes the fixed license number immediately to 50 (without rebooting). chlicense -f on : enables the floating licensing.
lsitab	Lists records in the /etc/inittab file.
chitab	Changes records in the /etc/inittab file.
mkitab	Adds records to the /etc/inittab file.
rmitab	Removes records from the /etc/inittab file.
telinit or init	Initializes and controls processes. 0-9 Tells the init process to put the system in one of the run levels 0-9. S,s,M,m Tells the init process to enter the maintenance mode. a,b,c Tells the init process to examine only those records in the /etc/inittab file with a, b, or c in the run-level field. Q,q Tells the init process to re-examine the entire /etc/inittab file. N Sends a signal that stops processes from being respawned. telinit q : requests the init command to re-examine the /etc/inittab file.
who	Identifies the users currently logged in. who -r : displays the runlevel. who /var/adm/wtmp : displays a history of logins, logouts, system startups, and system shutdowns.
restbase	Restores customized information from the boot image. Attention: The command is executed only during system boot phase 1. Do not execute it in a run-time environment.
savebase	Saves base customized device data in the ODM onto the boot device. savebase -d /dev/hdisk0 : save the ODM to the boot logical volume.

Hardware installation and configuration management Available hardware platforms: MCA-based uni-processor models (rs6k), MCA-based symmetric multiprocessor models (rs6ksmp), ISA-bus models (rspc), PCI-bus models (CHRP). AIX V5.2 is not supported on MCA and PReP architecture hardware. The "AIX Statement of Direction" gives a complete list of unsupported models.

lscfg	Displays configuration, diagnostic and VPD information about the system. lscfg -vp  : Displays the system model, machine serial, processor type, number of processors, processor clock speed, cpu type, total memory size, network information, filesystem information, paging space information, and devices information. lscfg | grep proc | wc -l : lists the # of processors.
prtconf or lsconf	Displays system configuration information. prtconf -s : displays the processor clock speed. prtconf -k : displays the kernel type in use. prtconf -m : displays memory.
snap	Gathers system configuration information. snap -a : gathers system configuration information. The output is written to the /tmp/ibmsupt directory.
uname	Displays the name of the current operating system. uname -a : displays the machine ID and version banner. uname -x : displays the operating system in use, the host name, the machine ID number of the hardware, the release number of the operating system, the operating system version and the system model name.
mach	Displays the processor architecture of the machine.
getconf	Displays system configuration variable values. getconf HARDWARE_BITMODE : displays hardware bit mode (64 or 32 bit). getconf KERNEL_BITMODE : displays kernel bit mode (64 or 32 bit). getconf DISK_SIZE /dev/hdisk2 : displays disk size in MB. getconf REAL_MEMORY : displays real memory size in MB.
cfg2html	A system configuration to HTML converter (Open Source)
file	Determines the file type. file prog : displays user process bit mode of program prog. Returns: executable (RISC System/6000) or object module not stripped (32 bit program), or 64-bit XCOFF executable or object module not stripped (64 bit program). file /unix : the returned link shows which kernel is running: unix_up = 32-bit uniprocessor kernel, unix_mp = 32-bit multiprocesssor kernel, unix_64 = 64-bit multiprocessor kernel.
cfgmgr	Configures devices by running the programs in /etc/methods directory and optionally installs device software. cfgmgr : runs the Phase 2 configuration rules (second boot phase for normal boot) (same as using the -s flag). cfgmgr -v : makes devices available that where not powered on when the system started. cfgmgr -l scsi1 : configures detected devices attached to the scsi1 adapter. cfgmgr -i /usr/sys/inst.images : installs device software (using the directory /usr/sys/inst.images) automatically during configuration.
chcons	Redirects the system console to device or file, effective next startup. chcons -a login=enable /dev/tty0 : changes the system console to device /dev/tty0. Use /dev/lft0 for the default LFT display. chcons /tmp/console.out : redirects the system console to file /tmp/console.out.
lsdisp	Lists the displays and the default display currently available on the system.
chdisp	Changes the display used by the LFT subsystem. chdisp -p gda1 : changes the default display permanently to gda1.
lsattr	Displays attribute characteristics and possible values of attributes for devices in the system. lsattr -EHl sys0l sys0 : displays system attributes (realmem ...) lsattr -EHl proc0 : displays the state, type and frequency of processor proc0. lsattr -El rmt0 : lists the current attribute values for the tape device rmt0. lsattr -El tty0 -a speed : lists the current value of the speed attribute for serial port tty0.
lsdev	Displays devices in the system and their characteristics. Examples: lsdev -P -H : lists the Predefined (supported) Devices (in the PdDv object class). lsdev -C -H : lists the Customized (configured/defined) Devices (in the CuDv object class). lsdev -C -c disk : lists all the PVs (class disk) in the system along with the status and location code.
listdgrp	Displays devices in a device class. listdgrp disk : list the devices in the disk class.
getdev	Lists devices that match the specified criteria. getdev type=proc_rspc : lists all devices of type proc_rspc.
getdgrp	Lists device classes that match the specified criteria. getdgrp : display all device classes.
chdev	Changes a device's characteristics. chdev -l hdisk2 -a pv=yes : assigns a PVID to hdisk2.
mkdev	Adds a device to the system. mkdev -l hdisk2 : make the already defined disk device hdisk2 available to use. mkdev -l hdisk1 -a pv=yes : makes an available disk a PV (assigning a PVID), if it does not already have one. mkdev -c tty -t tty -s rs232 -p sa0 -w s1 -a login=enable -a term=ibm3151 : adds an ibm3151 RS232 terminal using adapter sa0 port s1 with login enabled.
rmdev	Removes a device from the system. rmdev -l tty0 -d : removes the tty0 device definition from the CuDv object class (ODM). rmdev -l hdisk1 : unconfigures PV hdisk1 and changes its state from available to defined (definition is not removed from the CuDv object class (ODM).

Physical Volume Management See also lsdev, chdev, mkdev and rmdev.

lspv	Displays information about a physical volume (PV) within a volume group. lspv : lists the name, PVID and VG for each configured PV. lspv hdisk2 : lists the characteristics of PV hdisk2. lspv -M hdisk3 : lists the mapping and stale PPs for hdisk3. lspv -l hdisk0 : lists LV allocation within PV hdisk0. lspv -p hdisk1 : lists PP intra-allocation by PV region and PP state (free, used, stale, vgda) on hdisk1.
lquerypv *	Queries the attributes of a physical volume.
chpv	Changes the characteristics of a physical volume in a volume group. chpv -a n hdisk1 : turn off the allocation permission of free PPs for PV hdisk1. chpv -a y hdisk1 : turn the allocation permission for hdisk1 back on. chpv -v r hdisk3 : set the state of PV hdisk3 to unavailable (use when PV is to be removed from the system or is lost due to failure). chpv -v a hdisk4 : make PV hdisk4 available to the system (from state removed to active). chpv -h y hdisk2 : marks hdisk2 (with no allocated LPs) as a hot spare disk in a VG with mirrored LVs.
migratepv	Moves allocated PP's from one PV to one or more other PP's in the same VG. The command is not allowed if the VG is varied on in concurrent mode. migratepv hdisk1 hdisk3 hdisk5 : moves all PPs from hdisk1 to hdisk3 and hdisk5. migratepv -l lv02 hdisk2 hdisk4 : moves all PPs in LV lv02 from hdisk2 to hdisk4.

File System Management AIX supported file system types: standard Journaled File System (JFS) max. file size 2 GB, max. file system size 1 TB large file enabled JFS max. file size 64 GB, max. file system size 1 TB Enhanced Journaled File System (JFS2) max. file size tested 1 TB (AIX currently supports up to 16 TB using the 64-bit kernel, 1 TB using the 32-bit kernel), max. file system size tested 1 TB,  architectural max. file system size 4 PB. The JFS2 outline log can be up to 1 GB (32-bit kernel) and up to 64 GB (64-bit kernel).The JFS2 inline log size can be from 256 KB up to 16 GB. General Parallel File System (GPFS) Provides a cluster-wide file system allowing users shared access to files spanning multiple disk drives. RAM File System Up to 8 RAM disks can be created (2 GB size limitation is removed in AIX V5.2). Size cannot be changed afterwards. Network File System (NFS) NFS allows programs on one system to access files on another system transparently by mounting the remote directory. CD-ROM File System (CDRFS) A read-only local file system implementation under the logical file system (LFS) layer. Supported are ISO 9660:1988(E) standard, the High Sierra Group Specification, the Rock Ridge Group Protocol, the CD-ROM eXtended Architecture File Format (in Mode 2 Form 1 sector format only). CDs are automatically mounted by default. DVD-ROM File System (UDFS) A read-only file system stored on DVD-ROM media. UDFS format versions 1.50, 2.00, and 2.01 are supported. DVDs are automatically mounted by default. Cache File System (CacheFS) CacheFS is used to enhance read performance of remote file systems (NFS) or slow devices such as CD-ROM. CacheFS handles files larger than 2 GB. Default AIX file systems: fs lv description / hd4   The / (root) file system contains files and directories critical for system operation. /usr hd2 Files that can be shared by machines of the same hardware architecture are located in the /usr file system.  Architecture-independent, shareable text files, such as manual pages, are located in the /usr/share directory. /var hd9var  Variable per-client files, such as spool and mail files, are located in the /var file system. /home   hd1 The /home file system is the mount point for user home directories. /tmp hd3 The /tmp file system contains system-generated temporary files. /opt hd10opt  The /opt file system is reserved for the installation of add-on application software packages. /proc - The /proc pseudo file system provides access to the state of each active process and thread in the system by mappping processes and kernel data structures to corresponding files.

df	Reports information about space on file systems. df -m /usr : displays information about file system /usr in MB (-m) blocks (use -g for GB).
quot	Summarizes file system ownership. quot -f /home : displays the number of files and bytes owned by each user in the /home file system.
du	Summarizes disk usage. du -sg /home : displays the total disk usage in GB (-g) for all files in directory tree /home.
find	Recursively searches the directory tree with a matching expression. find . -type f -exec grep "unix" {} \; -print : looks for string "unix" and prints the names of the files in which it is found.
fileplace	Displays the placement of file blocks within logical or physical volumes. fileplace -v data3 : displays the placement of a file in its LV, including statistics on how widely the file is spread across the volume and the degree of fragmentation in the volume (-v).
lsfs	Displays the characteristics of file systems. Uses /etc/filesystems (system file with stanzas of the known file systems and their characteristics). lsfs : shows all file systems in the /etc/filesystems file. lsfs -q /usr : shows the LV size, file system size, the fragment size, the compression algorithm and the number of bytes per i-node (nbpi) of the /usr file system. lsfs -v jfs2 : shows all file systems of vfs type jfs2.
crfs	Adds a file system. The smallest file system is equal to one PP. crfs -v jfs -g datavg -a size=32M -m /user : creates a JFS of 32 MB with /user as the mount point in VG datavg. crfs -v jfs2 -g rootvg -a size=128M -m /data -A yes -p rw -a agblksize=2048 : creates a JFS2 of 128 MB with /data as the mount point, automatically mounted at system restart (-A), with 4K as the smallest file system block size that can be allocated to a file.
mkfs	Makes a new file system on a specified existing device (LV). mkfs -s 64M /data /dev/lvdata : creates an empty 64 MB file system on LV lvdata.  mkfs -o name=/user /dev/lvuser : creates an empty file system on the /dev/lvuser device, with mount point /user. The new file system occupies the entire device and has the default fragment size (4096 bytes) and the default nbpi ratio (4096).
chfs	Changes attributes of a file system. chfs -a size=+16M /data : increases the size of the /data file system by 16 MB. chfs -a size=64M /data : changes the size of the /data file system to 64 MB (provided it was previously no larger than this). chfs -A yes /data : sets the mount=true attribute in /etc/filesystems for file system with mount point /data.
rmfs	Removes a file system. rmfs -r /data : removes file system /data, it's mount point (-r) and it's LV.
reduce fs	Official procedure 1: 1. Make a backup of the file system. 2. Remove the file system. 3. Create a new file system using the same name and reduced size. 4. Restore the backup of the file system into the new file system. Official procedure 2: 1. Make a mksysb (VG rootvg) or savevg (other VGs). 2. Restore the VG using the shrink file systems option.
mount	Makes a file system available for use. mount : lists the mounted file systems. mount all or mount -a : mounts all file systems in /etc/filesystems marked by the mount=true attribute (file systems marked by the mount=automatic attribute are not mounted - they are mounted by the boot process). mount /dev/lvdata : mounts the file system (in LV lvdata) using the default mount point from /etc/filesystems. mount -v cdrfs -o ro /dev/cd0 /mnt : mounts the CDROM on /mnt.
umount or unmount	Unmounts a previously mounted file system, directory, or file. umount all : unmounts all file systems in /etc/filesystems marked by the mount=true attribute (file systems marked by the mount=automatic attribute are not unmounted). umount -f /mnt : forces the unmount of the /mnt NFS file system.
cdmount	Makes a file system available for use on a device managed by the cdromd daemon (automatically mounts a CD-ROM or DVD-ROM when it is inserted in a device, and provides the server function for all cd/dvd related commands). cdmount cd0 : mounts a file system on cd0. startsrc -s cdromd : starts the cdromd daemon which reads the /etc/cdromd.conf configuration file.
cdcheck	Asks cdromd daemon information about a device. cdcheck -m cd0 : asks cdromd if a CD is mounted on cd0.
cdeject	Ejects a media from a CD drive managed by cdromd. cdeject cd0 : ejects a CD from cd0.
cdumount	Unmounts a previously mounted file system on a device managed by cdromd. cdumount cd0 : unmount a file system on cd0.
fuser	Identifies processes using a file or file structure. fuser -u /data : lists the process numbers and user login names of processes using the /data file system.
defragfs	Increases a file system's contiguous free space by reorganizing scattered allocations. defragfs /home : defragments the /home file system. defragfs -s /data : generates a report on the fragmentation in the /data file system.
lmktemp	lmktemp largefile 1073741824 : Create a 1GB file named largefile.
fsck	Checks file system consistency and interactively repairs the file system. By default, the /, /usr, /var, and /tmp file systems have a check=false attribute in their /etc/filesystem stanzas. fsck -p /dev/lv00 : fixes minor problems with the /dev/lv00 file system automatically and if the primary superblock is corrupt, the secondary superblock is verified and copied to the primary superblock. dd count=1 bs=4k skip=31 seek=1 if=/dev/lvdata of=/dev/lvdata : copies the backup superblock of the /dev/lvdata file system over the primary superblock. fsck -V jfs2 /data : checks JFS2 with mount point /data for consistency and repairs problems found.
dd	Converts and copies a file. dd count=1 bs=4k skip=31 seek=1 if=/dev/lvdata of=/dev/lvdata : restores the backup of the superblock over the primary superblock (use when the superblock of the JFS on /dev/lvdata is corrupted (or dirty).
logform	Rebuild the JFS log. logform /dev/hd8 : rebuilds the jfslog of rootvg, after booting the machine into maintenance mode (attention: The logform command should only be run on closed LVs). logform -V jfs2 /dev/jfs2log : rebuilds the jfs2log /dev/jfs2log.
snapshot	Modifies, creates or queries properties a JFS2 snapshot (a consistent block level image of a file system). The bos.rte.file fileset must be installed. snapshot -o snapfrom=/data /dev/snapsb : creates a snapshot for the /data file system on the exisiting /dev/snapsb LV. snapshot -d /dev/snapsb : deletes the snapshot and the LV containing the snapshot.
backsnap	Creates and backs up a JFS2 snapshot. backsnap -m /tmp/snapshot/data -s size=16M -i -f /dev/rmt0 /data : creates a 16 MB LV, creates a snapshot for the /data file system on the created LV, mounts the snapshot on /tmp/snapshot/data and backups the files and directories in that file system by name to /dev/rmt0.
fsdb	Examines and modifies snapshot superblock, snapshot map, block xtree copy, and segment headers. Mounted file systems cannot be modified. fsdb /data : debugs file system /data.
dumpfs	Dumps file system information (superblock, i-node map, and disk map) for debugging. dumpfs /dev/hd2 : prints the information for /dev/hd2.
lsvfs	Lists entries in the /etc/vfs file.
crvfs	Creates entries in the /etc/vfs file.
chvfs	Changes entries in the /etc/vfs file.
rmvfs	Removes entries in the /etc/vfs file.
mkramdisk	Creates a RAM disk using a portion of RAM (pinned by default). Use only for data that can be lost. Setup procedure creating a 8 MB RAM disk: mkramdisk 8m ls -l /dev | grep ram mkfs -V jfs /dev/ramdiskx mkdir /ramdiskx mount -V jfs -o nointegrity /dev/ramdiskx /ramdiskx where x is the logical RAM disk number. To remove the RAM filesystem: unmount /ramdiskx rmramdisk /dev/ramdiskx
cfsadmin	Administers disk space used for CacheFS. cfsadmin -c /cache1 : creates a cache directory named cache1. mount -V cachefs -o backfstype=nfs,cachedir=/cache1 server2:/data /ldata : CacheFS-mounts the file system /data from remote host server2 on mount point /ldata of the client using cachedir /cache1. cfsadmin -l /cache1 : lists file systems and statistics for cache1. cfsadmin -d all /cache1 : removes all cached file systems from the /cache1 directory.
mkcfsmnt	Mounts a CacheFS directory. mkcfsmnt -d /mnt -t nfs -h server2 -p /home -c /cache1 -N : mounts the /home file system of server2 locally on the /mnt directory using /cache1 as CacheFS.
cachefslog	Controls the logging of a cache file system. cachefslog -f /cache1/cachelog /mnt : sets up the file /cache1/cachelog to log CacheFS statistics.
cachefswssize	Displays the work space size for a cache file system. cachefswssize /cache1/cachelog : displays the work space size of the cache filesystems being logged in the file /cache1/cachelog..
fsck_cachefs	Checks the integrity of data cached with CacheFS. fsck_cachefs -o noclean /cache1 : forces a check on the cache directory.

File Management

procfiles	procfiles -n `ls /proc` : lists all the process and files they have open.
find	find / -xdev -type f -mtime -1 -ls | sort +6nr | head -n 20 : lists the top-20 largest files in / that where used within the last 24 hours.

Logical Volume Management LVs automatically created at system installation are: hd5 boot LV (boot image). Available only at startup. hd6 Default paging space. hd8 Default logging space (jfslog) for the journaled file systems. hd4 / (root) file system. hd2 /usr file system. hd9var   /var file system. hd10opt /opt file system. hd3 /tmp file system. hd1 /home file system. Users' home directories. Note: hd7 was used in earlier AIX versions as dump device. Maximum LV size is 1 TB (32-bit kernel) or 128 TB (64-bit kernel). A dedicated dump device lg_dumplv is created in systems with at least 4 Gigabytes of real memory.

lslv	Displays information about a logical volume (LV). Total LVsize=PPsize * LPs assigned to LV * Number of LV copies. lslv lvdata : lists all the attributes related to LV lvdata. lslv -m lvdata : lists the LP to PP/PV mapping of LV lvdata.
mklv	Creates a logical volume. The smallest LV is equal to one PP. mklv -y lvdata -c 3 datavg 10 : creates LV lvdata in VG datavg with ten LPs and a total of three copies of the data. mklv -y lvdb datavg 50M : creates LV lvdb with a minimum size of 50MB (b/B=512B, k/K=KB, m/M=MB, g/G=GB). Rounded to whole LVs to make up 50 MB. mklv -a c datavg 2 : creates LV lv00 with a size of two LPs and intra-physical volume allocation policy center (e=[outer] edge, m=[outer] middle, c=center, im=inner middle, ie=inner edge).
chlv	Changes the characteristics of a logical volume. chlv -w p lvdata : turns on passive MWC for LV lvdata (big VG only).
rmlv	Removes logical volumes from a volume group. rmlv -f lvdata : remove LV lvdata without requiring user confirmation (attention: all data on this LV is destroyed).
extendlv	Increases the size of a logical volume by adding unallocated physical partitions. extendlv lvdata 12 : adds twelve more LPs to LV lvdata. extendlv lvraw 64M : adds 64 MB to LV lvraw. Rounded to whole LVs needed to make up 64 MB.
lquerylv *	Queries the attributes of a logical volume.
lreducelv *!	Reduces the number of allocated logical partitions of a logical volume (attention: if not used with care, data is lost). Official procedure to reduce a LV: 1. Back up all data in the logical volume. 2. Remove the logical volume. 3. Recreate the logical volume with the reduced logical partition allocation. 4. Restore the data.
cplv	Copies the contents of a logical volume to a new logical volume. cplv -v datavg -y lvnew lvold : copies the contents of lvold to new LV lvnew in VG datavg. cplv -e lvtest -f lvdata : copies the contents of LV lvdata to a smaller, existing LV lvtest within the same VG, without requiring user confirmation (attention: if lvtest is smaller than lvdata, then data will be lost, probably resulting in corruption).
mklvcopy	Adds copies to a logical volume. mklvcopy lvdata 3 : increases the number of copies in each LP in LV lvdata to three.
rmlvcopy	Removes copies from a logical volume. rmlvcopy lvuser 2 : decreases the number of copies in each LP in LV lvuser to two.
migratelp	Moves an allocated LP from one PP to another PP on a different PV in the same VG. migratelp datalv/23 hdisk3/105 : moves the 23th LP of LV datalv to the 105th PP of PV hdisk3. See lspv -p to display the free PPs of PV hdisk3.
splitlvcopy	Splits copies from one logical volume and creates a new logical volume from them. splitlvcopy -y newlv oldlv 2 : splits one copy of each LP belonging to the LV oldlv which currently has 3 copies of each LP, and creates the LV newlv.
getlvcb *	Displays a formatted output of the data in the LVCB of a LV. getlvcb -TA hd3 : displays the information held in the LVCB of LV hd3.
putlvcb *!	Writes the control block information (only the specified fields) into block 0 of a logical volume (LVCB). putlvcb -t jfs lvdata : writes the LV type jfs to the LVCB of LV lvdata.

Volume Group Management Each disk (PV) belongs to a Volume group (VG). A standard VG is a collection of 1 to 32 PVs (1 to 128 for a big VG). A PV can belong to only one VG. A maximum of 255 VGs can be defined per system. When a VG is created, the PVs within the VG are partitioned into contiguous, equal-sized PPs (units of disk space). PPs are the smallest unit of allocatable storage space in a VG. The PP size is determined at VG creation (can't be changed dynamically afterwards), and all PVs that are placed in the VG inherit this size. The PP size can range from 1 MB to 1024 MB, but must be a power of two. If not specified at creation time, the default PP size for a VG is 4 MB for disks up to 4 GB (the minimum PP size needed is determined by the OS), but it must be larger for PVs greater than 4 GB due to the fact that the LVM, by default, will only track up to 1016 PPs/PV. The number of PPs/PV (1016) can be increased with a factor 1-16 (or 1-64 for a big VG) at creation time or later (which will reduce the number of PVs in the VG) and/or the number of PVs/VG can be increased from 32 to 128 at creation time or later (big or gigantic VG). Importing a VG involves copying the VGDA data for the imported volume group into the ODM. When a volume group is exported, the data held in the ODM about that volume group is removed from the ODM database.

lsvg	Displays information about VGs. lsvg : lists all VGs. lsvg rootvg : lists the characteristics of VG rootvg. lsvg -o : lists only the active VGs (those that are varied on). lsvg -p rootvg : lists the PVs in VG rootvg (state, size, distribution). lsvg -l rootvg : lists the LVs in VG rootvg (type, size, state). lsvg -M rootvg : displays a map of all LVs.
lqueryvg !	Queries the attributes of a VG using VG id, or PV name of a PV that is part of a VG. lqueryvg -At -p hdisk0 : returns all attributes for the VG (static attributes, LV details and PV details).
mkvg	Creates a VG. mkvg -y datavg -s 32 hdisk2 hdisk4 : creates the VG datavg that contains PVs hdisk2 and hdisk4, with PP size set to 32 MB. mkvg -B -y uservg : create a big VG uservg (supports 128 PVs and 512 LVs).
chvg	Sets the characteristics of a VG. chvg -a{y|n} datavg : VG datavg is automatically activated (y=varyonvg) or not (n=varyoffvg) during system startup. chvg -u datavg : unlock the VG datavg. chvg -B datavg : changes the VG to big VG format (supports 128 PVs and 512 LVs). Mapping size is 4*original size. chvg -t 2 datavg : changes the limit of the number of PPs/PV by factor=2 (1016*2=2032 PPs/PV). Which decreases the number of disks (#PVs/factor=16 PVs/VG). chvg -sy datavg : attempts to automatically synchronize (AUTO SYNC) stale partitions in VG datavg (default this not done for a VG). chvg -L256 uservg : changes the LTG size to 256KB of VG uservg for better disk I/O performance. LTG size should be less than or equal to the maximum transfer size of all disks in the VG. Check each disk in the VG with: lquerypv -M hdiskx : checks the maximum supported LTG size of hdiskx. chvg -b n datavg : turns off the bad block relocation policy of VG datavg (default is yes for a VG). chvg -h y -s y uservg : sets policy in VG uservg to automatically (-h y) migrate PPs from one failing disk to one spare disk with automatic synchronization of stale PPs (-s y).
syncvg	Synchronizes LV copies that are not current (stale). syncvg -v datavg : synchronizes the copies on VG datavg. syncvg -p hdisk3 : synchronizes the copies on physical volumes hdisk3.
synclvodm	Resynchronize the ODM. The VG must be active. synclvodm rootvg : synchronizes the device configuration database with the LVM information for rootvg (use when the device configuration database is not consistent with the LVM information in the LVCBs and the VGDAs).
rvgrecover	Repairs the ODM.
mirrorvg	Mirrors all the LVs that exist on a given VG. mirrorvg -S -c 3 rootvg : triply mirrors VG rootvg, returns the mirrorvg command immediately and starts a background syncvg (-S). mirrorvg -m datavg hdisk3 : creates an exact mapped mirror of the LVs in VG datavg.
unmirrorvg	Removes the mirrors that exist on VGs or specified disks. unmirrorvg rootvg : default unmirroring of rootvg (rootvg now has only 1 copy).
importvg	Imports a new VG definition from a set of PVs. It is highly recommended that you run the fsck command before you mount the file systems. importvg -y datavg hdisk9 : imports VG datavg from PV hdisk9. importvg -y uservg 0009898xy2727d4f : imports VG uservg from PV with PVID 0009898xy2727d4f. importvg -L datavg : imports VG datavg and learns about possible changes. Use if the VG was not exported and used on another machine.
exportvg	Exports the definition of a VG from a set of PVs. exportvg datavg : removes VG datavg from the system.
redefinevg	Redefines the set of PVs of the given VG in the device configuration database.
extendvg	Adds PVs to a VG. extendvg datavg hdisk2 : adds PV hdisk2 to VG datavg.
reducevg	Removes PVs from a VG. When all PVs are removed from the VG, the VG is deleted. reducevg datavg hdisk3 : removes PV hdisk3 from VG datavg. reducevg datavg 000005265ac63976 : removes PV using it's PVID 000005265ac63976 from VG datavg (use when a disk was removed without first running reducevg).
reorgvg	Reorganizes the PP allocation for a VG. Using the reorgvg command with the VG name and no other arguments reorganizes only the first LV in the VG. reorgvg datavg lvdata1 lvdata3 : reorganizes LVs lvdata1 and lvdata3 on VG datavg.
recreatevg	Recreates a VG (with unique IDs, names, and mount points) on a set of disks that are mirrored from another set of disks. Imports and varies on the VG. Procedure after the real duplication of the PV (like mirroring): chdev -l hdisk5 -a pv=clear : to avoid potential collisions of LVM component names (PVID, VGname, ...) of hdisk5. recreatevg -y newvg -L /newfs -Y newlv hdisk5 : newvg is the newly assigned VG name, /newfs and newlv are used for prefixes of the newly assigned file systems and LVs, and hdisk5 is the duplicated target PV name.
splitvg	Splits a single mirror copy of a fully mirrored VG. splitvg -y snapvg -c 2 datavg : splits second mirror copy of the VG datavg and creates snapshot VG snapvg.
joinvg	joinvg datavg : joins the the original VG datavg with the snapshot VG snapvg.
varyoffvg	Deactivates a VG. varyoffvg uservg : deactivates the VG uservg.
varyonvg	Activates a VG. varyonvg -f datavg : used to force a varyon on VG datavg even when inconsistencies are detected (between the configuration data for each VG held in the ODM database and VGDA. varyonvg -r uservg : varies on VG uservg in read-only mode.

System Paging Space Management

lsps	Lists paging space and attributes. Configuration file: /etc/swapspaces (contains a list of swap devices). lsps :
chps	Changes attributes of a paging space. chps -a {y|n} paging00 : specifies that the paging space paging00 is active (y) or inactive (n) at subsequent system restarts. chps -s 10 paging02 : adds ten LPs to paging02 without rebooting. chps -d 5 paging01 : removes five LPs from paging01 without rebooting. chps -d 50 hd6 : removes fifty LPs from hd6 without rebooting.
mkps	Adds an additional paging space to the system. mkps -a -n -s20 datavg : creates a permanent paging space pagingxx in VG datavg of 20 LPs and activates it immediately.
rmps	Removes a paging space from the system (exept hd6). rmps paging00 : removes deactivated paging space paging00.
swapoff	Deactivates one or more paging space. swapoff paging01 : deactivates paging space paging01.
swapon	Activates a paging space. swapon paging01 : activate paging space paging01. swapon -a : activates all paging spaces defined in /etc/swapspaces.
swap	Displays paging characteristics and enables the allocation and deallocation of paging devices. swap -l : displays device, major and minor numbers, and total and free space. swap -a /dev/paging01 : activates paging space paging01 (like swapon). swap -d /dev/paging01 : deactivates paging space paging01 (like swapoff).
migratepv	migratepv -l hd6 hdisk0 hdisk2 : moves hd6 from hdisk0 to PV hdisk2 within the same VG (always use VG rootvg for hd6 performance).

Communications Management

rc.tcpip	Script that initializes selected TCP/IP daemons using SRC at each system restart: inetd, lpd, portmap, sendmail, syslogd (started by default) and gated or routed, named, timed, xntpd, rwhod, snmpd, dhcpcd, mrouted, autoconf6 (not started by default unless they are uncommented). stopsrc -g tcpip : stops all running TCP/IP daemons. stopsrc -s named : stops the named daemon. /etc/rc.tcpip : starts all selected TCP/IP daemons. Don't use startsrc -g tcpip (would start all subsystems in the tcpip group). startsrc -s named : starts the named daemon. refresh -s inetd : refresh the inetd subsystem (re-reads /etc/inetd.conf).
/etc/tcp.clean	sh /etc/tcp.clean : stops all running TCP/IP daemons (not portmap and nfsd) and removes all /etc/locks/lpd TCP/IP lock files.
inetd daemon	Provides Internet service management for a network. Starts by default using the /etc/inetd.conf configuration file. Daemons controlled by the inetd daemon: ftpd, rlogind, rexecd, rshd, talkd, telnetd, and uucpd (started by default) and tftpd, fingerd, and comsat (not started by default unless they are uncommented). resfresh -s inetd : informs the inetd daemon of the changes to its configuration file. The ports inetd listens on are in /etc/services (unless they are commented).
lsdev	Displays devices in the system and their characteristics. lsdev -Cc if : lists IP interfaces.
lscfg	Displays configuration, diagnostic, and VPD. lscfg -l ent0 -v : displays the VPD for ent0.
lsattr	Displays attribute characteristics and possible attribute values for devices. lsattr -HEl en0 : displays effective values for interface en0.
netstat	Shows network status. netstat -in : shows status of IP interfaces with numeric addresses. netstat -rn : shows status of TCP/IP routes with numeric addresses. netstat -C : shows routing table, user-configured and current costs of each route. netstat -v : shows device driver statistics.
arp	Displays and modifies address resolution. arp -a : displays local ARP cache (ip to mac address table).
no	Manages network tuning parameters. Changes are valid until the next reboot. no -a : displays kernel variable values. no -o ipforwarding : displays if ipforwarding is on (=1) or off (=0). no -o ipforwarding=1 : specifies the kernel should forward packets (acting as an IP router).
ifconfig	Configures or displays network interface parameters for TCP/IP. ifconfig -a : displays information about all interfaces in the system. ifconfig en0 : displays network interface parameters for en0. ifconfig en0 inet 194.186.152.2 netmask 255.255.255.0 up : assigns IP-address 194.186.152.2 with network mask 255.255.255.0 to interface en0 of address family inet and turns on the network card. ifconfig en0 down : turns off network card en0.
route	Makes manual entries into the network routing tables until next reboot. route -rn : displays route table. route add -inet -net 9.19.98.1 9.19.99.10 : adds a network route to the routing table for destination host 9.19.98.1 through gateway 9.19.99.10.
lsattr	Displays attribute characteristics and possible values of attributes for devices. lsattr -El en0 : lists the current attribute values for en0.
nslookup	Queries Internet domain name servers. nslookup : enters interactive mode. nslookup nserver1 : returns the domain name and Internet address of nserver1.
traceroute	Displays the route that IP packets take to a network host. traceroute server2 : displays all the hops from local host to server2.
iptrace daemon	Provides interface-level packet tracing for Internet protocols.
ipreport	Generates a trace report from the specified trace file created by the iptrace command.
ping	Sends an echo request to a network host. ping -c 6 server1 : checks the network connection to host server1 by sending 6 echo requests. ping -f server2 : invokes the flood-ping option to host server2. ping -R : displays the full round trip route of a packet.
spray	Sends a one-way stream of packets to a host and reports performance statistics using the RPC (default) or ICMP protocol (two-way stream). spray server1 -c 1000 -d 4 : sends 1000 packets at intervals of 4 microseconds to server1.
host	Resolves a host name into an Internet address or an Internet address into a host name. System files: /etc/hosts (local hosts table). host server1 : displays the Internet address and name aliases of host server1. host 192.186.154.3 : displays the host whose address is 192.186.154.3.
hostid	Sets or displays the identifier of the current local host.
hostname	Sets or displays the name of the current host system. hostname tulip : changes the hostname to tulip until the next reboot. chdev -l inet0 -a hostname=server1 : changes the hostname permanently to server1.
mktcpip	Sets the required values for starting TCP/IP on a host.
rwho	Displays which users are logged in to hosts (that run rwhod) on the local network. rwho -a : lists all users currently logged in to hosts on the local network.
ruptime	Displays the status of each host (that runs rwhod) that is on the local network. ruptime -al : lists a status report of each host on the local network sorted by load average.
lsnamsv	Shows name service information stored in the database /etc/resolv.conf (name resolver).
chnamsv	Changes TCP/IP-based name service configuration on a host.
mknamsv	Configures TCP/IP-based name service on a host for a client.
rmnamsv	Unconfigures TCP/IP-based name service on a host.

User/Group Management

dispuid	Displays all valid user IDs on the system.
logins	Displays user and system login information. logins -p : lists all the logins with no passwords.
lsuser	Displays attributes of user accounts. lsuser ALL : displays all the attributes of all the users.
mkuser	Creates a new user account. System files: /etc/passwd (contains basic user attributes) and /etc/group (contains basic group attributes). The default attributes are in the /usr/lib/security/mkuser.default file. mkuser erik : creates the erik user account.
passwd	Changes a user's password. System files: /etc/security/passwd (contains password information). passwd hans : changes the password of user hans.
pwdadm	Administers users' passwords (by root or a member of the security group).
chsec	Changes the attributes in the security stanza files. chsec -f /etc/security/login.cfg -s default -a pwdprompt="Password:" : changes the system-wide password (echo's user name) prompt to Password (doesn't echo user name. chsec -f /etc/security/login.cfg -s default -a usernameecho=false : hides the user name from login and system messages.
mkuser.sys	Customizes a new user account.
chuser	Changes attributes for the specified user.
rmuser	Removes a user account. rmuser -p erik : removes user erik. rm -r /home/erik : removes erik's home directory.
dispgid	Displays all valid groups on the system.
lsgroup	Displays the attributes of groups. lsgroup ALL : lists all groups.
chgroup	Changes attributes for groups (don't use in combination with NIS).
chgrpmem	Changes the administrators or members of a group.
mkgroup	Creates a new group.