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Lpar Memory Configuration – Guidelines for MaxMem

Guidelines for MaxMem

  • Don’t set MaxMem equal to total amount of server memory for each LPAR. This will waste memory with oversized HPTs.
  • Size MaxMem approximately 25 percent larger than Desired Memory for production LPARs that might require a DLPAR memory addition. For less important LPARs, which could be shutdown for a desired memory increase, set the MaxMem as close as possible to the Desired Memory.
  • Always set the MaxMem to a power of two to maximize DLPAR growth options.



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Corrupted transaction log in AIX

we can boot AIX in maintenance mode -> access rootvolume group-> Access this Volume Group and start a shell before mounting file systems

# logform -V jfs /dev/hd8
# fsck -y -V jfs /dev/hd1
# fsck -y -V jfs /dev/hd2
# fsck -y -V jfs /dev/hd3
# fsck -y -V jfs /dev/hd4
# fsck -y -V jfs /dev/hd9var
# fsck -y -V jfs /dev/hd10opt
# exit

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Re-creating the boot logical volume on AIX

boot the system in maintenance mode

-> Access to the root Volume Group

# bosboot -ad /dev/hdiskX  (rebuild  hd5)

# Shutdown -Fr  ( important !! All changes need to be written from memory to disk.)

The bosboot command requires that boot logical volume (hd5) exists. If we lose the Boot logical Volume (BLV) then we can re-create …

here are the steps:

we boot the system in maintenance mode

1) Access  System Management Services (SMS)  to select boot device.

2) Remove the old hd5 logical volume

# rmlv hd5

3) clear the boot record at the beginning of the disk

# chpv -c hdiskX

4) Create a new hd5 logical volume

# mklv -y hd5 -t boot -a e rootvg 1    (one physical partition size)

5) execute  bosboot command

# bosboot -ad /dev/hdiskX

6) check the actual bootlist

# bootlist -m normal -o

7) Write data immediately to disk

# sync


8) Shutdown and reboot the system

# Schutdown -Fr

internal command ipl_varyon -i can give state of the boot record.

 # ipl_varyon -i

PVNAME          BOOT         DEVICE                                       PVID                                                      VOLUME GROUP ID
hdisk4                 YES                                                                00c341f22286d95c0000000000000000        00c341f200004c00
hdisk0                  NO                                                                 00c341f227932d2f0000000000000000        00f73df900004c00




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Add a UDF file system on a DVD-RAM

• Create a UDF file system
# udfcreate -d /dev/cd0
• Change the label on a UDF file system
# udflabel -d /dev/cd0 -l testdvd
• Create a mount point
# mkdir /dvddisk
• Mount a UDF file system
# mount -V udfs -o rw /dev/cd0 /dvddisk
• Check a UDF file system
# udfcheck -d /dev/cd0

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Add a RAM file system on AIX

• Create a RAM disk of 16 MB
# mkramdisk 16M
• Create a JFS file system on this RAM disk
# mkfs -V jfs /dev/ramdisk0
mkfs: destroy /dev/ramdisk0 (yes)? y
• Create mount point
# mkdir /ramdisk
• Mount RAM file system
# mount -V jfs -o nointegrity /dev/ramdisk0 /ramdisk

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Create user on VIO server with the view rights

1 ) login into VIO Server via padmin

2) change to root : oem_setup_env

3) Create user via smitty

* User NAME                                           selim
  User ID                                            [203]                                                                                                                                                                                  #
  ADMINISTRATIVE USER?                                false                                                                                                                                                                                +
  Primary GROUP                                      [staff]                                                                                                                                                                               +
  Group SET                                          [staff]                                                                                                                                                                               +
  ADMINISTRATIVE GROUPS                              []                                                                                                                                                                                    +
  ROLES                                              [ViewOnly]                                                                                                                                                                            +
  Another user can SU TO USER?                        true                                                                                                                                                                                 +
  SU GROUPS                                          [ALL]                                                                                                                                                                                 +
  HOME directory                                     [/home/selim]
  Initial PROGRAM                                    [/usr/bin/ksh]

4) Edit the file /etc/security/user  and put this line:


             admin = false

              default_roles = ViewOnly

now our user Selim could show the environment without change permission.

$ whoami
$ /usr/ios/cli/ioscli lsmap -vadapter vhost0
SVSA            Physloc                                      Client Partition ID
————— ——————————————– ——————
vhost0          U8205.E6B.063DF9R-V2-C20                     0x00000004

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SUDO implementation in AIX

1) download the package from

for example sudo-1.8.8-1.aix5.1.ppc.rpm

2) Install the package via rpm – ivh  sudo-1.8.8-1.aix5.1.ppc.rpm

after installation , check the version sudo -V

3)  Edit the configuration file für sudo  vi /etc/sudoers or  directly  # visudo

put the user and the right into it.

4)  we can put sudo activities into a file. We can put two lines into config file

Default      syslog=auth

Default      logfile=/var/log/sudo.log           # after that we can see the activities.

 # cat /var/log/sudo.log
Jan  6 16:10:16 : selim : TTY=unknown ; PWD=/home/selim ; USER=root ;


AIX installed/updated Filesets

lslpp -qch | awk -F: ‘ { printf  ” %-14s %-40s %-15s\n ” , $7,$2,$3} ‘ | sort | uniq | sed  ‘ s/70/-70/’ | sort -t  ‘/’  -k 3,3n -k 1,1n -k 2,2n


Get information about devices in AIX

Table 1. Commands to get information about your devices

Command Description
lsdev -C -H -F "name status physloc location description" Get the AIX ( if present) and physical location codes.
lsdev -Cc disk -F 'name location physloc' Get the AIX and physical location codes of all disks.
lsdev -Cl hdisk0 -F physloc Get the location code of hdisk0.
lscfg -vpl hdisk0 Get extended information o fhdisk0.
lsdev -C| grep hdisk0 Get the AIX location code of hdisk0.
lsparent -Cl hdisk0 Get the parent devices for hdisk0.
lscfg -l fcs0 Get information about the fsc0 device.

MustGather: Application Server, dmgr, and nodeagent start and stop problems

Collecting data manually,

If an Application Server, dmgr or nodeagent is not able to start when issuing the command startServer servername, startManager, or startNode at the command line, or if an Application Server is unable to start or stop using the Network Deployment Administrative console, collect the following documents using one of the tracing methods below.

Tracing from the WAS_PROFILE/bin command line:

  1. Backup and purge the logs in the following directories:
  2. Open the following file:
  3. Change the following string:
    • From:

    • To:

  4. Change the following string:
    • From:

    • To:

  5. Save the changes.
  6. Run the following command:
    startServer servername -trace
    This will log the trace to the startserver.log file located in the following directory:
    If you want the trace to be written to a unique file, run the following command:
    startServer server_name -trace -logfile path_to/servertrace.out
    Note: If you specify the -logfile option with only a filename and you do not specify a directory path for the log file, the file will be created in the WAS_PROFILE/bin directory.
  7. Similarly, if the Application Server does not stop when issuing the command: stopServer server_name, stopManager or stopNode. Follow the same procedure documented above for collecting trace documents, running the command stopServer. stopManager, or stopNode in place of startServer.
  8. Run the collector tool on both Network Deployment (for federated environment only) and Base Application Server profiles.
  9. Follow instructions to send diagnostic information to IBM support.


Tracing in the administrative console:

  1. Backup and purge the logs in the following directories:
  2. In the administrative console, expand the Troubleshooting section and click on Logs and Trace.

  3. Click on the link for your server.
  4. Click on Change Log Detail Levels.
  5. Change the following string:
    • From:

    • To:

  6. Increase the Maximum Number of Historical Files from 1 to 10.
  7. Click on Apply and save and synchronize your configuration.
  8. Stop and restart the Application Server, dmgr, or nodeagent.
  9. Run the collector tool on both Network Deployment (for federated environment only) and Base Application Server profiles.
  10. Follow directions in MustGather: Readme First to open a PMR and send data to IBM Support.
  11. Follow instructions to send diagnostic information to IBM support.