IBM AIX Administrator key terms

A system configuration database on AIX made of object classes stored in files under /etc/objrepos, /usr/lib/objrepos and /usr/share/lib/objrepos. Commands such as lsdev, lspv and mkdev read and write device and system records here.

A command that lists devices defined in the ODM, optionally filtered by class or subclass. With -C it shows customized devices and with -P predefined ones, helping you confirm whether hardware is detected and configured.

The configuration manager command that scans the bus and configures newly attached or detected devices into the ODM. Run after adding adapters or disks so the system recognizes them without a reboot in most cases.

The ODM object classes, chiefly CuDv, CuAt and PdDv, that record each device's name, status, attributes and predefined support. Tools such as lscfg and lsattr query these records to report hardware details.

A command that displays detailed configuration and vital product data for devices, including model, serial number and location code. Use lscfg -vl ent0 to see adapter microcode and FRU information useful for support calls.

A structured identifier describing a device's physical position in the hardware topology, such as 00-08-00-1,0. It maps adapters and disks to slots and enclosures, which is essential when tracing a failed component in the field.

A command that lists attributes and current values for a device or the system. With -El it shows all attributes including defaults, and with -F it prints just a chosen field for scripting.

A command that changes attributes of a configured device, such as media speed on an adapter or queue depth on a disk. Some changes require the device to be in the Defined state first.

A command that removes a device from the ODM or changes it to the Defined state. With -d it deletes the definition entirely, so use it carefully on disks that still hold data you may need.

A collection of physical volumes managed as one unit of storage, holding logical volumes. It records metadata in a volume group descriptor area, and can be varied on or off as a whole.

A disk or LUN that has been assigned to a volume group with mkvg, addvg or extendvg. Identified by a PVID written to the disk, it is divided into physical partitions when used in a volume group.

A named, resizable unit of storage inside a volume group that maps logical partitions to physical partitions. It is the layer that filesystems, paging spaces and raw devices are built on.

The allocation unit of a logical volume, mapped one-to-one or mirrored to physical partitions on one or more disks. Its size, set at volume group creation, determines how finely storage can be allocated.

A fixed-size chunk of a physical volume, typically 4, 8, 16, 32 or 64 MB, set by the volume group's PP size. Logical partitions are mapped onto these chunks, and mirroring copies them to other disks.

The physical volume identifier, a unique 16-character value written to a disk when it joins a volume group. It lets the system recognize the disk's membership even if its device name changes.

A command that reports physical volume information such as PVID, volume group membership, total and free partitions, and allocation state. With -l it lists the logical volumes residing on a given disk.

A command that activates a volume group, making its logical volumes available for use. It reads the volume group descriptor area and reports any missing disks, which may require recovery steps.

A command that deactivates a volume group after all its logical volumes are closed, releasing the disks for maintenance or export. It fails if filesystems or paging spaces in the group are still active.

A command that removes a volume group's definition from the ODM without touching the data on its disks, allowing the disks to be moved to another system and imported there.

A command that reads an existing volume group's descriptor area on a disk and recreates its definition in the local ODM, typically after moving disks from another system. It also updates /etc/filesystems entries.

A command that creates copies of a volume group's logical volumes on separate physical volumes for redundancy. After mirroring, run bosboot and update the boot list so the system can boot from either copy.

A command that synchronizes stale mirrored partitions after a disk outage or a new mirror copy is added. It copies current data to the stale copies so redundancy is restored.

The enhanced journaling filesystem used by default on AIX, supporting large files, dynamic inode allocation and online growth. It logs metadata changes so a crash requires fast replay rather than a full check.

The stanza-based configuration file that defines mount points, devices, filesystem types and mount options on AIX. Commands such as mount, mkfs and crfs read and update stanzas here.

A command that creates a filesystem, logical volume and /etc/filesystems stanza in one step. Options set the volume group, size, mount point and whether the filesystem is mounted immediately.

A command that checks and repairs filesystem consistency, usually run on an unmounted filesystem. On JFS2 it replays the journal and fixes metadata problems, and it should not be run casually on mounted filesystems.

Disk-backed virtual memory used when RAM is overcommitted, configured as logical volumes typically named hd6 and others. Commands lsps and chps report and adjust paging space characteristics.

A command that displays paging space usage, including size, percent used and whether the space is active. With -s it shows a summary, and with -a it lists all paging logical volumes.

The System Management Interface Tool, a menu-driven interface for administration tasks that also records the underlying commands in a log. It offers fast paths such as smit lv to jump directly to a task screen.

A file in the user's home directory recording commands executed through SMIT, including output and errors. Reviewing it helps you learn equivalent command-line syntax or diagnose a failed menu operation.

A command that displays entries from the system error log, showing identifiers, classes, types and timestamps. Options such as -a list all entries and -d show detail for a specific error identifier.

A command that deletes error log entries older than a specified number of days, or by identifier and class. It is used to keep the error log manageable after resolving a recurring fault.

A short alphanumeric label in the error log, such as a disk or adapter failure code, that identifies the type of error. It is used with errpt -d and errclear to filter and act on specific errors.

The daemon that records system messages to files configured in /etc/syslog.conf, typically /var/adm/ras or /var/log. Restart it with refresh -s syslogd after changing the configuration.

The ordered list of devices the system tries when booting, managed with the bootlist command. After mirroring the root volume group or moving disks, update it so alternate boot devices are usable.

A command that rebuilds the boot image on a disk, writing the kernel and device configuration needed to start AIX. Run it after mirroring the root volume group or changing boot-related device configuration.

A procedure that clones the root volume group to a second disk so the system can boot from it if the primary fails or an update goes wrong. It is often used before applying maintenance updates.

A command that checks whether APARs or fix packs are installed, using -k to test a specific APAR and -i to list installed fixes. It reads fix information from installed filesets and the fix database.

A command that reports the operating system level, technology level and service pack. With -s it shows the maintenance level, and with -g it shows the highest installed level, useful for support checks.

An Authorized Program Analysis Report, IBM's identifier for a specific software defect and its fix. Administrators check whether relevant APARs are installed before opening a support case.

The smallest installable software package unit on AIX, with a name, version, release, modification level and fix level. Commands lslpp and installp list, install and update filesets.

A command that lists installed filesets and their states, such as APPLIED or COMMITTED. With -L it shows detailed information including prerequisites and the files a fileset contains.

The command that installs, updates, commits, rejects and removes filesets. Options such as -a apply updates, -c commit them and -r reject them, while -g previews actions without changing the system.

An AIX framework for installing and maintaining clients over the network from a master server, using resources such as lpp_source and spot. It centralizes OS deployment and updates for many systems.

A NIM resource directory holding installation images and updates that clients can install from. It is created from media or downloaded fixes and referenced by NIM install operations.

A Shared Product Object Tree, a NIM resource containing the boot image and device support needed for network boot and installation. Clients boot from a SPOT during NIM installs.

A command that creates a bootable backup image of the root volume group, including filesystems and system configuration. The image can restore a system or be used as a NIM installation resource.

The Trusted Computing Base check command that verifies security-critical files against a stored database. It can report or fix permission and attribute deviations on files that affect system security.