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The following method describes the procedure of performing a Kernel Upgrade on IBM i-Series /DB2. Since the AS/400 specific procedure is different from any other OS platforms. Kernel upgrade can be performed successfully using the APYSIDKRN command which takes care of all manual actiions – like checks, backups, permissions etc., from versions 7.20 and above. In the past, various commands were used for performing this single activity, now SAP has simplified the procedure with the introduction of a single command APYSIDKRN. Have documented this for beginners who are new to i-series, any inputs or feedback is highly appreciated. Various projects might have followed different approaches, but we have been practicing the following method without any issues.

Reference SAP Notes:  1) Note 1632755 for more information on APYSIDKRN command

                                     2) Note 1432807 for restore old kernel back again

Technical Steps

Step 1: Downloading the Kernel Copying Media to your IBM i

Step 2: Stop SAP System

Step 3: Upgrade kernel using APYSIDKRN

Step 4: Start SAP System and validate

1) Download the OS/400 kernel files from market place and copy to you IBM i


Copying the files manually to IBM i

The required installation media has to be copied from your Windows PC to your IBM i. To copy the media, you have to use a binary share ROOTBIN. This guarantees that the content of the media is copied correctly from the Windows PC to your IBM i. No copied content is corrupted, and no copied files with longer file names are shortened by a converting share. Binary Share – ROOTBIN will be created during an initial installation, if not please refer to i-series installation guide on creating a ROOTBIN directory.


Create a folder kernel_741U_43 under ROOTBIN for example and place the SAR files in the directory (Don’t have to extract them – the tool will take care of the uncar)



2) Stopping the SAP System

Log on to the VM for i-series and connect to the server using Emulator (All i-series tools will be installed under IBM i Access for windows)



Soon after we log in, the system prompts for specific operation we want to perform.


Stop the SAP system


Step 3: Upgrade kernel using APYSIDKRN

Check the existing kernel version of the system

Run disp+work -v from kernel directory (/sapmnt/SID/exe/uc/as400_pase_64)

(To run user friendly UNIX commands like other operating systems – we can use Q SHELL, simply enter the following command at the initial screen CALL QP2TERM – which will take you to terminal, general commands can be run from there like cd, ls, cp, rf etc.,)



RUN the program APYSIDKRN from command line



Just give the path of the kernel dump which we gave in Step 1 in the field Archives to be applied : /kernel_741U_43/*

The program will automatically look for files in ROOTBIN and under that the dump we mentioned.


The APYSIDKRN will automatically prepare the environment, take back up of the existing kernel, check the Archive SAR files, kernel compatibility; it will also give options for Mode of Operation to ADD the files to the existing kernel, TEST, FULLY – to upgrade kernel versions directly also (ex from 720 to 721)

ADD is option is to OVERWRITTEN existing files

TEST option is to Simulate, no changes will be applied but we can identify and analyze any problems to be expected when applying patches

FULLY – Program directly is completely emptied before it is filled with new kernel files.


Old kernel automatically backed up to /sapmnt/SID/patches/saved/xxx.SAR


Once kernel upgrade is finished the program automatically exits.

Check the newly upgraded patch level same as above

Step 4: Start SAP System and validate




It took 15 minutes for the complete procedure and to bring up PI 7.4 system.

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1 Comment

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  1. João Dimas

    Hello durga gidugu,

    I performed the Kernel update (7.21 version (NUC) from patch level 402 to 801) using this blog and everything works fine! Thank you very much durga gidugu.

    I had only one error/problem when I did a simulate (using the *TEST mode):

    APYSIDKRN: Some mandatory patches are missing – check joblog or log and apply them too

    To correct this issue I followed the SAP note 2172659 (IBM i: APYSIDKRN: Some mandatory patches are missing … with SAPHOSTAGENT 7.21)


    Many thanks,

    João Dimas



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