What is ODM ?
- ODM – Object Data Manager is the database for storing system information.
- Physical and logical devices information are stored and maintained as objects in ODM.
- It is in binary format hence can't view or edit.
- Whenever we add, delete and configure the devices in OS, the entries will be added in ODM
System Data Managed by ODM
1) Device Configuration information (Predefined and Customized Devices )
2) Software Vital Product Data (SVPD)
3) System Resource Controller
4) TCP/IP configuration information
5) SMIT menus and commands
6) NIM information
7) Error Log and dump information.
Data Not Managed by ODM
The Filesystem information, User/Security information and Queues & its devices are not manged by ODM.
How ODM is compared with Rational Database?
ODM is more or less similar to Relational Database.
1. Object Class is equivalent to the database file.
2. Objects are equivalent are to the row of the database.
3. Object descriptors are equivalent to the column of the database
OC -- datafiles
O -- recordsOD -- fields
Where the ODMDIR environment variable declared?
ODMDIR environment variable is declared in /etc/environment. The default ODMDIR variable is /etc/objrepos.
Types of ODM Components & Commands associated with them
ODM have 3 components, they are Object Classes, Objects and Descriptors
Object Classes: (odmcreate, odmdrop)
The ODM contains many database files. Each file is called Object Class.
#odmcreate desc_file.cre (Create ODM class file)
#odmdrop -o desc_file.cre (Delete entire ODM class)
Each object class contains of objects. Each object is one record in an object class
#odmget -q name=hdisk0 CuDv
The above command is used to display the object hdisk0 in the CuDV
#odmdelete –o CuDv –q name=hdisk0
The above command is used to delete the specified object hdisk0 in ODMe
It describes layout of the object. They determine the name and datatype of the fields that are part of the object classes.
Device Configuration Summary
What are Device Database aka Object Class files?
There are 2 important device database or Object class files are there in ODM, they are Predefined device and Customized device
- Predefined device information describes all supported devices. (PdDv,PdAt,PdCn). If the device to be configured, it must be the part of PdDv class, it is not possible to configure a device without defined in the corresponding Pd classes.
- Customized device information describes all the devices that are attached to the system. (CuDv, CuAt, CuDep, CuDvDr, CuVPD, Config_Rules). If the device is in defined state, it should have entry in CuDv.
What are the states of devices in the ODM?
There are 2 important states of devices in the ODM, they are Defined and Available
Defined State (device status will be 0 )
- If a device is in the defined state there is an entry in ODM class CuDv.
- A device can be either defined by cfgmgr or mkdev command . Both methods use “define method” (cfgmgr) to generate instance in the class CuDv.
- Suppose that installed device is removed from server or hdd has failed. This case that device is moved to defined state. i.e. that device configuration is available in server but currently device is not accessible.
Available State (device status will be 1)
- When the device is in available, the device driver has been loaded and special device file is configured under /dev directory and the device is ready for accessible.
- The "configure method" is used to load the device driver and add an entry in the /dev directory
In addition to the above the following state also availble
The device is supported device but not configured. Devices reside in the Predefined Database not customized database.
NoteThe difference between Defined and Available state is that no device driver loaded into the kernel.
What are the commands used to get device informations?
- lsdev command to get information about PdDv and CuDv.
- lsattr command to get information about PdAt and CuAt.
SWVPD (Software Vital Product Data)
- VPD is the Vital Product data which is the subset of ODM.
- Using lscfg can find the VPD data of the hardware devices.
The following are objects of VPD
1) LPP (Contains information about the product)
2) Inventory ( contains files associated with s/w product)
3) Product ( information of the prdt)
4) History (Historical info about software)
Object Class Repositories
There are 3 repositories, in which ODM data are stored.
- This is the main repository file. Data that is specified to the system is stored.
- /(root) part of the s/w contains the part of the product that cannot be shared through networks.
- Customized Devices object classess (CuDv,CuAt)
- Predefined device object classess (PdDv.PdAt)
- Platform specific data that can be shared across the network.
- SMIT menu objectclasses and /usr part of the SWVPD.
- The four object classes used by SWVPD for the /usr part of installable s/w prdt sofw installed in /usr part can be shared among the h/w arch
- /usr/share part of the SWVPD (history, inventory,lpp,product).
- Platform independent data can be shared across the systems.