Hardware Management Console (HMC)

A Hardware Management Console (HMC) is an Linux based appliance used to manage IBM Power Systems servers. HMC is used to:
  • Add / Remove LPARs
  • Manage logical partitions and partition profiles
  • Perform Dynamic LPAR (DLPAR) operations. (DLPAR operations that change the resource allocation (such as processor, memory, physical I/O, and virtual I/O) dynamically for the specified partition)
  • Activate and manage Capacity on Demand resources
We can perform above functions without rebooting the operating system running in the LPAR.

A single HMC can control multiple Power Systems server and multiple HMCs can manage a single Power System. An HMC can be used via either an X-Windows graphical user interface (GUI) or an SSH command line interface (CLI).

An HMC is necessary only to manage Power Systems servers. Once configured, Power Systems servers continue to operate normally even if the HMC is shut down. But please note that larger Power Systems servers (Power 760 and above) require an HMC to successfully power up. Once a server is powered up, the HMC is no longer required for the server to continue to operate normally. An HMC also provides access to the console of every virtual machine (LPAR) on every managed server. 

As of Oct 2015, the latest version of HMC is V8R8.1.0 

Note: LPAR (Logical Partitioning) is a way of subdividing all of a computer’s resources, including the memory, storage, and processors, and splitting them up into smaller logical units that can each be run as a separate part of the operating system (OS)

Library List

A list that indicates libraries used for the process and the order in which it has to be searched. There can be 40 libraries in library list (15 System & 25 application). 

A library list is identified by the type *LIBL. A default library list is automatically created by  IBM i (previously known as i5/OS or OS/400) for each job started by a user. Your default library, that is the library that has the same name as that as your user profile, is automatically included in your library list.

Add a Library to Library list: To add a library to the library list, type the “Add Library List Entry” (ADDLIBLE) command, followed by the library name (or prompt on the command) Eg: ADDLIBLE XXXXXX

Edit Library List & Change Current Lib: You can edit your library list using the EDTLIBL command and remove a library list entry using the RMVLIBLE command. “XXXXXX” can be made the current library by typing CHGCURLIB Yourlib.

Display Library List (DSPLIBL): When you display your library list. Your library list should look like

PS: You may not have all the libraries in the above list.

Program Temporary Fixes (PTFs)

A program temporary fix (PTF) is a temporary solution to a bug on AS400. A PTF is temporary only in the sense that it disappears with the next release of the product, when the code patch is integrated into the base product code. PTFs are recommended to keep the system up to date and current. 

Types of Fixes or PTFs: Many different kinds of fixes exist, and each fix has its own purpose. 
  1. Single fixes: Single PTFs are applied to correct specific reported problems. The following are descriptions of the different types of single fixes that exist: 
    • High-impact pervasive (HIPER) PTF: A HIPER PTF resolves a severe problem that can have a high impact on IBM OS/400 or IBM i5/OS operations, or it can resolve a low-impact but pervasive problem that affects most IBM iSeries family of servers. The following are examples of these types of situations:
      •  Your system crashes or hangs, and it requires a restart or IPL (initial program load) to recover.
      •  Your system is stuck in a looping condition.
      •  Your system's data integrity is threatened.
      •  Your system experiences a severe performance degradation, or the problem involves the usability of a product's major function.
    • Pre-requisite fix: A pre-requisite fix is a fix that must be installed on your server before or at the same time as the fix that you want to install. The system will prevent you from installing your fixes if you do not have the prerequisite fixes. Your fix cover letter or PSP information can identify other fixes that must be installed before or at the same time as the fix that you want to install.
    • Co-requisite fix: A co-requisite fix must be installed at the same time as the fix that you are requesting to install. Your fix cover letter or PSP information can identify other fixes that must be installed before or at the same time as the fix that you want to install. In addition, system error messages can notify you that the fix that you are attempting to install has requisite fixes. The system checks that the co-requisite fixes are installed at the same time. In this case, you must verify that your fixes installed successfully.
    • Technical Refresh requisite fix: The technical refresh PTF is required to be permanently applied to the system before you can load this fix.
    • Distribution requisite fix: A distribution requisite fix is required for distribution purposes only. A distribution requisite fix is sent and installed only if it is named by a fix listed in a fix group and you are using that fix group to send or install fixes. If you are sending only a fix, then the distribution requisite fix is not sent and installed. The system does not require you to apply distribution requisites.
    • Delayed fixes: Some fixes cannot be applied immediately because the licensed programs they affect are active. These fixes are called delayed fixes and can be applied only at the next IPL. Delayed fixes that affect the Licensed Internal Code can be applied immediately when running on the A storage area. The cover letter tells you if the PTF is immediate or delayed.
    • Immediate fixes: Immediate fixes can be applied without doing an IPL if the objects that they affect are not in use, or they can be applied when you do the next IPL. The cover letter tells you if the PTF is immediate or delayed.
    • Defective PTF: A PTF that does not do what it was intended to do or has damaging effects. It’s a PTF that when applied may work for a vast majority of it’s customers but not you. There may be a unique situation at your installation that the PTF will not resolve. This makes it defective. 
    2. Cumulative PTF packages: Cumulative PTF packages contain fixes for a given release of the OS/400 or i5/OS operating system and associated licensed programs. As the name implies, each package is cumulative; that is, it contains all of the fixes from the previous package plus additional fixes released since the previous package. Many, but not all, new fixes are included in cumulative packages.

    The fixes that are not included are typically applicable only to a specific user's situation or application. These fixes are not included for general availability to avoid introducing unwanted change and potential programming errors into a cumulative package where code quality has the highest priority. When you order the cumulative PTF package, you also receive the most recent Database PTF group and the HIPER PTF group.

    3. Fix groups (Group PTFs): A PTF group, or fix group in iSeries Navigator terminology, is a name that is used to order and manage a group of logically related PTFs. It consists of a list of PTFs that are defined for the purpose of managing those PTFs as one entity. A PTF group can identify other PTF groups, called related PTF groups. 

    The cumulative PTF package is shown as a PTF group on the Work with PTF Groups ( WRKPTFGRP) screen and in the Management Central fix group inventory.

    4. Service packs: Service packs are different from group PTFs. A service pack is a collection of code fixes (not PTFs) for iSeries Access for Windows products that are contained in a single OS/400 or i5/OS PTF. 

Initial Program Load (Reboot)

Initial program load (IPL) means load the initial (first) programs into main storage so that the processor can use them to do work for you. An IPL resets system storage (cleans out what was there and replaces it with new data). In other words, IPL means start your system. The following situations typically require an IPL:

  • Starting local or remote operations when the system power is off
  • Applying certain program temporary fixes (PTFs)
  • Installing new system hardware
  • Starting a system after a problem prevents all jobs from working
  • Main storage dumps 
AS/400 has a variety of modes, speeds, and types of initial program loads to fit a variety of needs.

Operating mode: You use the operating mode to determine the number of options that are presented to the operator for consideration during and after the initial program load (IPL). It can also secure (lock) the control panel to prevent an unauthorized or inadvertent IPL from the control panel. There are four operating modes:

Normal (unattended)
After the power-on, operating the system in Normal (unattended) mode requires no operator intervention during the IPL. When you power on the system in normal mode, it performs the IPL and presents the Sign On screen on all available display stations. The operator cannot change the system during the IPL. Dedicated Service Tools (DST) and the operating system do not present any displays during this IPL.
Use a normal mode (unattended) IPL to do this:

  • Perform an IPL and run the system for most routine work
  • Perform a remote IPL
  • Power on and perform an IPL by date and time
Manual (attended)
After power-on, operating the system in Manual (attended) mode means that an operator uses the control panel to direct the system for special needs. During manual mode IPL, DST and the operating system present menus and prompts that allow you to make changes to the internal system environment. This can include entering debug mode for service representatives to diagnose difficult problems.
Use manual mode to IPL and run the system to perform the following actions:

  • Change IPL options (including system values)
  • Install the operating system
  • Load program temporary fixes (PTFs)
  • Make some types of system hardware upgrades
  • Use DST (for advanced users and service only)
  • Problem diagnosis (for advanced users and service only)
Auto (automatic)
Use Auto mode for an automatic remote IPL, automatic IPL by Date and Time, and an automatic IPL after a power failure.

Use Secure mode to prevent use of the control panel to perform an IPL. This mode is not a form of IPL; it is a means to prevent an unauthorized or inadvertent IPL from the control panel. 

IPL types: The IPL type determines which copy of programs your system uses during the initial program load (IPL).
There are four IPL types:

IPL type A
Use IPL type A when directed for special work, such as applying program temporary fixes (PTFs) and diagnostic work. For example, use IPL type A in the following circumstances:

  • When IPL type B fails
  • When the procedures direct you to use IPL type A
  • When you suspect problems with temporary Licensed Internal Code PTFs 
IPL type A uses the A copy of Licensed Internal Code during and after the IPL. This copy of Licensed Internal Code is the permanent copy. It is said to reside in System Storage Area A. It contains no temporarily applied PTFs.

IPL type B:
Use IPL type B for routine work and when directed by a PTF procedure. This type of IPL runs the newest copy of Licensed Internal Code and is necessary when you permanently apply certain PTFs. IPL type B uses the B copy of Licensed Internal Code during and after the IPL. This copy is said to reside in System Storage Area B. This copy contains temporarily applied PTFs. 

IPL type C
This type of IPL is reserved for hardware service representative use under the direction of Rochester development support. Attention! Do not use this function! Severe data loss can occur with improper use of this function.

IPL type D
Use IPL type D when directed for special work, such as installing and reloading programs. IPL type D loads the system programs from an alternate IPL load source, such as a tape drive or CD-ROM.
Usually an IPL uses programs stored on the primary IPL load source (usually a disk drive). Sometimes it is necessary to perform an IPL from another source, such as programs stored on tape. To do this, you must use IPL type D to IPL from the alternate IPL load source.
Use IPL type D only during one of the following situations:

  • When install or restore procedures direct you to use IPL type D
  • When IPL type B and IPL type A fail (when the primary IPL load source cannot IPL the system properly) and only when directed by your support personnel
  • When service directs you to perform an alternate install

System Values

System values (*SYSVAL) are AS/400 attributes that let each installation customize the machine to the organization's needs and specifications. Some system values control system performance; others define security levels; yet others simply provide defaults to command options that are unspecified.

**Note : There are total 150 system values as following in the iSeries machine.

Below are the few system values
QMODEL - Holds the system model number and can't be modified.
QSRLNBR - Contains the preloaded serial number.
QMAXSIGN  - Specifies how many invalid sign-on attempts are allowed.
QMAXSGNACN - Specifies the action to take when the QMAXSIGN limit is reached.
QSECURITY  - Indicates the security level; valid levels are 10, 20, 30, 40, and 50.

The system value QTIME contains the system time of day. It comprises three other system values, QHOUR (based on a 24-hour clock), QMINUTE, and QSECOND

The system value QCURSYM determines the currency symbol, which is country dependent; for example, the yen, lira, franc, and dollar use different symbols.

The following are complete list of system values
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