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It is a database of system and device configuration information integrated into the OS. It is intended for storing system informations: software infos (smit menus and commands, installed filesets...) and device infos (device configurations, tcp/ip configs...)

For safety reasons the ODM data is stored in binary format.
All ODM commands use the ODMDIR environment variable, that is set in file /etc/environment. The default value of ODMDIR is /etc/objrepos.


ODM can be divided into 3 parts:

- Object Classes (odmcreate, odmdrop):
The ODM consists of many database files, where each file is called an object class.

odmcreate descriptor_file.cre            it creates an ODM class (descriptor_file.cre contains the class definition)
odmdrop -o object_class_name            it deletes an entire ODM class

- Objects (odmshow):
Each object class consists of objects. Each object is one record in an object class.

odmshow object_class_name            it shows the underlying layout of the objec class

- Descriptors (odmadd, odmchange, odmdelete, odmget):
The descriptors describe the layout of the objects. They determine the name and datatype of the fields that are part of the object class.


ODM object classes are held in 3 repositories:

/etc/objrepos:(Cu* classes and / (root) part of SWVPD)

- CuDv (Customized Device): It contains entries for all device instances defined in the system. (A defined device has been created by the define method, but an actual device no necessarily should be attached to the system)

- CuAt (Customized Attribute): It contains customized device-specific attribute information. Devices in CuDv have attibutes in PdAt and CuAt. Attributes taking the default value are found in PdAt, and attributes with customized values are in CuAt.

- CuDep (Customized Dependency): It contains logical dependencies. (i.e. dependency between lv and a vg, physical device dependencies are stored in CuDv)

- CuDvDr (Customized Device Driver): It stores the major and minor numbers of devices. (Some programs use these special files to access a certain device.)

- CuVPD (Customized Vital Product Data): It contains vital product data (manufacturer of device, part number, and so forth) that is useful for technical support. When an error occurs with a specific device the vital product data is shown in the error log.

- Config_Rules: There is one ODM object class which the cfgmgr uses to determine the correct sequence when configuring devices.

/usr/lib/objrepos:(Pd* classes and /usr part of SWVPD)

- PdDv (Predefined Devices): It contains entries for all devices supported by system. A device that is not part of this could not be configured on AIX.

- PdAt (Predefined Attribute): It contains attributes for each device represented in the PdDv object class. These attributes become the default values if they are not modified. Modified attributes are written to the CuAt.

- PdCn (The Predefined Connection): It contains information about how devices physically connect to the system.

- sm*: SMIT menu are located in the folowing files : sm_cmd_hdr, sm_cmd_opt,sm_name_hdr, sm_menu_opt

/usr/share/lib/objrepos: (/usr/share part of SWVPD)


Software Vital Product Data

Whenever installing a product or update an AIX, installp command uses ODM to maintain SWVPD. It contains name of the software, version, Applied, Commited..
SWVPD consists of 4 classes which are sored at 3 different places (see image above).

3 places of SWVPD:

- /etc/objrepos: root part (/) of SWVPD
The root part of the software contains the part of the product that cannot be shared among machines.

- /usr/lib/objrepos: /usr part of SWVPD
Software installed in the /usr-part can be shared among several machines with compatible hardware architectures.

- /usr/share/lib/objrepos: /usr/share part of SWVPD
These files are not hardware dependent, they can be shared among several machines even if the machines have a different hardware architecture

To display classes stored at different places, change ODMDIR (i.e. ODMDIR=/usr/lib/objrepos) then rerun odmget command. (ODMDIR defaults to /etc/objrepos)

4 classes of SWVPD:

- lpp: contains information about the installed program, state, description... (odmget -q name=Java14.sdk lpp)

- inventory: contains information about the files associated with the program (odmget -q lpp_id=264 inventory)

- product: contains information about the product, i.e: prerequisites (odmget -q lpp_name=Java14.sdk product)

- history: contains historical information about the installation and updates (odmget -q lpp_id=264 history)

These object classes are linked together by the lpp_id descriptor.


Object Classes:

PdDv, PdAt - CuDv, CuAt:

Predefined device information describes all supported devices.
Customized device information describes all devices that are actually attached to the system.

If a device is to be configured, it must be part of the PdDv class. It is not possible to configure a device that is not defined in the corresponding Pd classes. If a device is in the defined state, there is an entry in ODM class CuDv.  When a device is available, the device driver has been loaded and a special file is created in the /dev directory (these special files are used by applications to access the device drivers loaded into the kernel). The difference between the defined and available state is, that no device driver has been loaded into the AIX kernel.

1. When a device is defined in AIX, the device must be defined in ODM class PdDv.

2. A device can be defined by either the cfgmgr (if the device is detectable), or by the mkdev command. Both commands use the define method to generate an instance in ODM class CuDv. The configure method is used to load a specific device driver and to generate an entry in the /dev directory.

3. At this point, you only have default attribute values in PdAt, which means for a terminal you could not log in (default is disable) and the terminal type is dumb. If you change the attributes, for example, log in to enable and term to ibm3151, you get objects describing the nondefault values in CuAt.


The lsdev command actually gets its information from the PdDv and CuDv files.
The lsattr command actually queries the PdAt and CuAt files.


echo $ODMDIR                default value is /etc/objrepos, it can be set in /etc/environment
(odm commands (odmget..)will work in the dir which is set in $ODMDIR. You can change it, so you can find items (swvpd) from root or usr part)
ODMDIR=/etc/objrepos        odm commands will get the / (root) part of the SWVPD
ODMDIR=/usr/lib/objrepos    odm commands will get the /usr  part of the SWVPD

odmcreate <descriptor_file.cre>     create an ODM class
odmdrop -o <object_class_name>      delete an entire ODM class
odmshow <object_class_name>         view the undelying layout of an object class (i.e: odmshow PdAt)

odmget ...                          queries objects in classes (odmget PdDv: will list all the predefined devices)
odmadd ...                          add new objects to an object class
odmdelete ...                       delete objects (odmdelete -q name=paging00 -o CuAt)
odmchange ...                       changes objects

=      equal
!=     not equal
>      greater
>=     greater than or equal to
<      less than
<=     less than or equal to
like   similar to; finds path names in character string data
?      odmget -q "name like hdisk?" CuDv
*      odmget -q "name like hdisk*" CuDv

some examples:
odmget -q name=hdisk0 CuDv
odmget -q "name=hdisk0 and attribute=pvid" CuAt
odmget -q "lpp_name=bos.rte.filesystem and fix=52" product

odmget -q "name like hdisk?" CuDv           
odmget -q "value3 like hdisk?" CuDvDr

odmdelete -q "lpp_name=bos.rte.filesystem and fix=52" -o product


getlvodm -j <hdisk>    get the vgid for the hdisk from the odm

getlvodm -t <vgid>     get the vg name for the vgid from the odm
getlvodm -v <vgname>   get the vgid for the vg name from the odm

getlvodm -p <hdisk>    get the pvid for the hdisk from the odm
getlvodm -g <pvid>     get the hdisk for the pvid from the odm


chdef (changing parameters in PdAt)

I wanted to increase queue_depth value in PdAt, but to avoid any odm manipulation used chdef command:
chdef -a attribute=value -c <Class> -s <subclass> -t <type>

1. odmget -q attribute=queue_depth PdAt | grep -p vscsi    <--to check current value
2. lsdev -H -F "name class subclass type" | grep hdisk     <--to check class, subtype, type which is needed for chdef
3. chdef -a queue_depth=32 -c disk -s vscsi -t cvdisk      <--it will increase queue_depth to 32 in PdAt

after odmget will show our new value.


Deleting a disk completely from ODM:

For example if rmdev command does not work:

# rmdev -dl hdiskX
Method error (/etc/methods/undefine):
        0514-009 Cannot delete an object from the device
                 configuration database.

1. find disk in ODM customized database: 
   odmget -q name=hdisk# CuAt
   odmget -q value=hdisk# CuAt
   odmget -q name=hdisk# CuDv
   odmget -q value3=hdisk# CuDvDr
   odmget -q name=hdisk# CuDep
   odmget -q name=hdisk# CuVPD
   odmget -q name = hdisk# CuPath
   odmget -q name = hdisk# CuPathAt

2. remove disk entries from ODM customized database: 
   odmdelete -q name=hdisk# -o CuAt
   odmdelete -q value=hdisk# -o CuAt
   odmdelete -q name=hdisk# -o CuDv
   odmdelete -q value3=hdisk# -o CuDvDr
   odmdelete -q name=hdisk# -o CuDep
   odmdelete -q name=hdisk# -o CuVPD
   odmdelete -q name=hdisk# -o CuPath
   odmdelete -q name=hdisk# -o CuPathAt


Changing Attribute Values:

1. odmdelete and odmadd commands

-we want to change default block size to 1024:
odmget -q"uniquetype=tape/vscsi/ost and attribute=block_size" PdAt

        uniquetype = "tape/vscsi/ost"
        attribute = "block_size"
        deflt = "512"   
        values = "0-2147483648,1"
        width = ""
        type = "R"
        generic = "DU"
        rep = "nr"
        nls_index = 2

-create a temporary file:
odmget -q"uniquetype=tape/vscsi/ost and attribute=block_size" PdAt > ODM_tape_file

-change the value to 1024:
vi ODM_tape_file

-before adding the new object, the old object must be deleted otherwise we would have 2 objects:
odmdelete -q"uniquetype=tape/vscsi/ost and attribute=block_size" -o PdAt              
(if we have 2 objects with the same type, the 1st one will be used)

-add the new object:
odmadd ODM_tape_file
(The first line of the file will contain which object class this entry should go (here PdAt) )

2. odmchange command
(It does the same as the delete and the add operations, but all in one step)

odmget -q name=et0 CuDv > ODM_et_file
vi ODM_et_file
odmchange -q name=et0 -o CuDv ODM_et_file


Fixing ODM problems of non-rootvg:
1.umount fs -> varyoffvg homevg
2.exportvg homevg                       <--remove completely from ODM
3.importvg -y homevg hdiskX             <--import vg by creating new ODM objects (-y: specify the vg name)
for rootvg: rvgrecover


Checking in which class to look for an entry:

cd /etc/objrepos
grep -l paging00 *                      <--lists the name of the files (once) which contain matching line



lppchk -v shows problems with a fileset and you don't want to (or can't) remove it:
devices.common.IBM.iscsi.rte    (not installed; requisite fileset)

1. save ODM
   tar -cvf /tmp/odm.tar /etc/objrepos /usr/lib/objrepos

2. check lpp_id
   odmget -q name=devices.common.IBM.iscsi.rte lpp
   output will show lpp_id:
    lpp_id = 355

3. delete from /etc/objrepos (lpp,product, history, inventory) (check odmdir: echo $ODMDIR)
   export ODMDIR=/etc/objrepos
   odmdelete -q name=devices.common.IBM.iscsi.rte -o lpp
   odmdelete -q lpp_name=devices.common.IBM.iscsi.rte -o product
   odmdelete -q lpp_id="355" -o history
   odmdelete -q lpp_id="355" -o inventory

4. delete from /usr/lib/objrepos (lpp,product, history, inventory) (check odmdir: echo $ODMDIR)
   export ODMDIR=/usr/lib/objrepos
   odmdelete -q name=devices.common.IBM.iscsi.rte -o lpp
   odmdelete -q lpp_name=devices.common.IBM.iscsi.rte -o product
   odmdelete -q lpp_id="355" -o history
   odmdelete -q lpp_id="355" -o inventory

   export ODMDIR=/etc/objrepos (sets back ODMDIR to its original value)
   check lppchk -v if it is OK now

5. (if needed) reinstall base fileset with force flag (then update)
   installp -aF -d /home/bb/bb1 all


   update to the required level


FIXING FILESETS: (SPECIFIC:bos.rte.printers)
A fileset is in Broken state and no Base install fileset has been found (so we could not do a force install)
(We had a good base fileset, and a failed updated fileset.)

Plan: Clean up from ODM the failed updated fileset, then update again.)

1. lppchk -v shows:
     bos.rte.printers               (BROKEN)

2. checking where is it broken:
    lslpp -lc | grep bos.rte.printers
    /usr/lib/objrepos:bos.rte.printers: End Printer Support:
    /etc/objrepos:bos.rte.printers: End Printer Support:

3. backing up ODM:
    tar -cvf /tmp/odm.etc.tar /etc/objrepos
    tar -cvf /tmp/odm.usr.lib.tar /usr/lib/objrepos

4. checking fileset in the ODM (ODMDIR is set here /etc first):
    odmget -q lpp_name=bos.rte.printers product                <--fileset exists only here and here 5.3.8 version exists, mod=8)
    odmget -q lpp_name=bos.rte.printers lpp                    <--here nothing

5. export ODMDIR=/usr/lib/objrepos                             <--problem occured at /usr, so ODMDIR has been changed to it

6. now checking the ODM in /usr/lib/objrepos:
    odmget -q lpp_name=bos.rte.printers product                <--here 5.3.10 version exists, mod=10)

7. final check to identify the corect entry what we need to delete (mod=10)
    odmget -q "lpp_name=bos.rte.printers and mod=10" product   <--mod=10 is the updated version
    odmget -q "lpp_name=bos.rte.printers and mod=8" product    <--mod=8 is the base version

8. deleting from ODM:
    odmdelete -o product -q "lpp_name=bos.rte.printers and mod=10"    <--updated version deleted

9. after that update was OK:
    smitty update_all

10. setting back ODMDIR (no problem if omitted):
    export ODMDIR=/etc/objrepos                                 <--if login again it will be refreshed from /etc/environment


Changing ODM parameters of the HDLM driver:

root@aix1 : /home/padmin # odmget PdAt > /tmp/PdAtbackup_091119
root@aix1 : /home/padmin # odmget -q"uniquetype=disk/fcp/Hitachi and attribute=reserve_policy" PdAt > /tmp/pdatreserve_policy

Edit /tmp/pdatreserve_policy:


        uniquetype = "disk/fcp/Hitachi"
        attribute = "reserve_policy"
        deflt = "no_reserve"
        values = "no_reserve,single_path,PR_exclusive,PR_shared"
        width = ""
        type = "R"
        generic = "DU"
        rep = "sl"
        nls_index = 96

# odmchange -o PdAt -q"uniquetype=disk/fcp/Hitachi and attribute=reserve_policy" /tmp/pdatreserve_policy


Major/Minor numbers from ODM:

odmget -q "value3=lp1" CuDvDr

Should return something like:



The major number is 15 and minor 2.


Mike said...

Thanks a lot

aix said...

Welcome :)

Anonymous said...

where can i get ODM for HP EVA8000 arrays?

aix said...

This is written in the HP EVA documentation:
"6. Download the devices.fcp.disk.HP.hsv.mpio. file from the following HP web site:

Anonymous said...

Is there an IBM doc that covers defining your own MPIO disk types using odmadd? I've got an R&D system with iscsi storage from a Solaris ZFS array. The disks are not being detected as MPIO despite being capable of it. I'd like to create my own ODM definition but I'm having trouble finding information on the topic.

aix said...

I could only find an IBM course: AW15 - AIX 5L Quickstart for UNIX Professionals
There is an exercise about this:
"At the end of the exercise you should be able to:
- Define the meaning of the most important ODM files
- Work with the ODM command line interface
- Describe how ODM classes are used from device configuration commands
An optional part provides how to create self-defined ODM classes, which is very interesting for AIX system programmers."

Unfortunately I don't have that exercise :(

Anonymous said...

Perfect site, congratulations.
This here is just extract of the most important from Advance Administration and Problem Determination course. Very useful

Unknown said...

THis is one of the most Lucid and informative site to learn AIX fundamentals :)
Just noticing one typo here so thatught of notifying...
In one section it is mentioned that /etc/objrepos is part of / SWPD and /usr/lib/objrepos is for /usr.
""""3 places of SWVPD:

- /etc/objrepos: root part (/) of SWVPD
The root part of the software contains the part of the product that cannot be shared among machines.

- /usr/lib/objrepos: /usr part of SWVPD
Software installed in the /usr-part can be shared among several machines with compatible hardware architectures."""

Whereas in other few paragraphs below it is mentioned:
""ODMDIR=/etc/objrepos odm commands will get the /usr part of the SWVPD
ODMDIR=/usr/lib/objrepos odm commands will get the / (root) part of the SWVPD""
Please help me to determine which one is correct ...
Thanks !!!

aix said...

Hi, thanks for finding this typo. The first section is correct, I fixed later examples to show correct data. :)

Anonymous said...

Hi I am new to AIX Environment. can anybody plz help me how to add the filesystem in aix software repsitory

Anonymous said...

Thanks a lot, it's absolutely one of the best AIX sites in the net. Why official IBM documentation isn't so clear?

aix said...


Unknown said...
This comment has been removed by the author.
Unknown said...

Thanks a lot.
I have a question, Do ODM storing filesystems information(mount point) ? I just know that a label vaule of a lv has nothing with its mount point.
I met an error that system couldn't obtain the related lv via the filsystem name which get from "odmget -q name = lv02 and attribute = label CuAt"
(error during the process of hacmp bring resouce gorup offline)

"release_vg_fs[+122] odmget -q name = lv02 and attribute = label CuAt
cl_deactivate_fs(24.710)[fs_umount+16] lsfs -c /12
lsfs: No record matching '/12' was found in /etc/filesystems.
cl_deactivate_fs(24.720)[fs_umount+18] cl_echo 24 'cl_deactivate_fs: Failed obtaining logical volume for /12 from ODM.\n' cl_deactivate_fs /12"

name = "lv02"
attribute = "label"
value = "/12"
type = "R"
generic = "DU"
rep = "s"
nls_index = 640

dev = /dev/lv02
vfs = jfs2
log = INLINE
mount = false
check = false
options = cio,rw
account = false

D3viL said...

hey! thanks a lot.
Do you know th reason of static route absence in ODM?
I have it listed in net stat -nr as a UHS but it is absent in ODM.

Unknown said...

What is the latest ODM Version for EMC Storage for AIX 6.1

Used PC Exporter said...

Nice Blog Post !