Restrictions and limitations within a versioned WPAR

Edit online

A versioned WPAR provides a different version runtime environment than the global system. Versioned WPARs have some limitations as compared to local system WPARs.

Limitations of functions within a versioned WPAR follow:
  • File systems cannot be shared with other WPARs.
  • Commands and features not supported by the AIX® version of the runtime environment are not supported in the WPAR, even though they might be available in the global system.
  • Adapters cannot be exported to a versioned WPAR.
  • If a rootvg WPAR is created, the standard JFS file systems are not supported. When the file systems are created on a WPAR-owned rootvg, the JFS file systems from the system image are converted to JFS2 file systems.
  • Some commands from the AIX 7.1 environment replace commands from the original AIX environment that used to populate the versioned WPAR, including but not limited to the following types of commands:
    • File system commands
    • Logical volume commands
    • System performance commands
    To see the files within a versioned WPAR that are replaced by local or alternative programs, run the following command within the versioned WPAR:
    ODMDIR=/usr/lib/objrepos odmget file_overlay | awk '$1=="path" {print $3}'
    If you have AIX 5.2 Workload Partitions for AIX 7 version 1.1.0, run the following command:
    ODMDIR=/usr/lib/objrepos odmget overlay | awk '$1=="path" {print $3}'
Unlike local system WPARs, it is possible for applications running within a versioned WPAR to access a limited number of symbols through the /dev/kmem interface in read-only mode. The accessible symbols are as follows:
  • avenrun
  • cpuinfo
  • enter_dbg
  • iostat
  • pacefork
  • sysinfo
  • tickadj
  • v_exempt_secs
  • v_min_process
  • v_repage_hi
  • v_repage_proc
  • v_sec_wait
  • vmminfo

Versioned workload partitions use the device configuration methods from the global logical partition (LPAR), because they depend on device drivers in the kernel and therefore must have a compatible version. However, there is predefined device configuration data that the configuration methods depend on that is maintained separately in the WPAR, because all versioned WPAR are detached WPAR with their own private copy of the /usr file system, which stores the device configuration data. This might cause issues if the predefined device data in the WPAR is out of sync with the corresponding data in the LPAR, because data on which the configuration methods depend might be incorrect or missing. This out-of-sync condition occurs when the global LPAR is updated and the updates include new or changed predefined device data. It can also occur if the global LPAR base level is newer than the AIX release that was current when the vwpar product was shipped. The static updates to the predefined device data when the vwpar filesets are installed in the WPAR do not include the most recent data. The predefined device configuration data in the WPAR might be synchronized with the global LPAR by using the -c option of the syncwpar command.