SAP Note

Header Data

Symptom

You want to set up and activate the "VM Container" component, which is delivered with the SAP NetWeaver server.

Other Terms

IPC, VMC, VM Container, Virtual Machine Container

Reason and Prerequisites

The component is deactivated in the kernel in the delivered version, since it is not required for all applications in the system. You should only activate the component "VM Container" after the installation or the upgrade, since you can only install or upgrade with a validated kernel, but the component "VM Container" may require a higher patch level (see Step 1 below).

Solution

Step 1

The VM Container requires at least patch level 29 for the 7.00 kernel. You require patch level 260 or higher for the optimal configuration as described in SAP Note 1083358. Starting with kernel 7.01, the VMC is available in each release. The VM container patches are contained in the DW.SAR archive or in the SAPEXE.SAR archive. SAP Note 19466 describes how to apply the patches.

Step 2

You can activate the VM Container using the profile parameters mentioned below, which can be changed using profile maintenance (transaction RZ10). Once you have made the change, you need to restart the server instance. You need to change the following parameters: vmcj/enable = on In addition, set the shared memory area that is used by the VM container in accordance with SAP Note 1020539 (Memory management in the VM container) or 1170313 (Zero administration memory management in VMC). SAP Note 1020539 is used only to calculate the size of the shared pool; the setting should be made in accordance with SAP Note 1170313 or 1083358. Activating the VM Container increases the swap space and shared memory required by an SAP NetWeaver application server instance. The increased demand S (in MB) depends on the number of work processes you are using (parameter rdisp/wp_no_*), and can be calculated as follows:   S = (rdisp/wp_no_dia +        rdisp/wp_no_vb  +        rdisp/wp_no_vb2 +        rdisp/wp_no_btc + 2) * (JH + VH) + P JH = The value of the profile parameter vmcj/option/maxJavaHeap (200M according to the suggestion given above) VH = Value of the profile parameter vmcj/max_vm_heap_MB (the designated default value is 64 (MB)) P = Value of the profile parameter vmcj/option/ps (760M according to the proposal in SAP Note 1020539) For a system with 16 work processes in total (8 online, 1 update task, 1 V2 update program, 3 batch, 1 spool), the value 5256 MB results from the above parameter proposal, therefore approximately 5.3 GB. The spool work process is not included for the calculation. Two further VMs that cannot be used from external sources (application) (template VM and Auto Java VM) exist for this. The template VM is omitted from the operating system HP-UX. You can use the following profile parameter to set the maximum number of (usable) VMs: rdisp/max_jvm = REM=<number> Make sure that you provide enough additional swap space before you activate the VM container. On Unix platforms you also have to provide enough shared memory. For further information, refer to the

    854170 - Switching on the component "VM Container"  

Version   32     Validity: 13.01.2014 - active   Language   English

Released On 13.01.2014 14:06:30

Release Status Released for Customer

Component BC-VMC Virtual Machine Container

Priority Recommendations / Additional Info

Category Installation information

"Installation Guide SAP NetWeaver 2004s", section 3.2 "Hardware and Software Requirements".

Known problems

1) If the swap space provided is not sufficient or if, for example, the kernel parameter SHMMAX was not adjusted on HP-UX, the insufficient memory may cause terminations in the container or you may not be able to start the system. 2) We advise against using the VM Container on 32-bit platforms for production operation due to the restricted address space. However for 32-bit usage for test purposes in older systems, the following recommendations may help to reduce the memory requirement:

l Reducing the paging and roll buffer. If you reduce the parameter rdisp/PG_SHM or rdisp/ROLL_SHM by the value of 16384, you receive 128 MB additional address space in each case.

l If you use vmcj/option/ps = 256M instead of 768M (as is listed in Note 1020539), you receive 512 MB of additional address space.

l If you use vmcj/option/maxJavaHeap = 100M instead of 200M as listed above, you receive 100 MB additional address space.

l Windows: Note 129813 describes how the address space can become defragmented on Windows. This allows you to use the 3 GB address space more efficiently. For using the VM container on Windows, you must activate the Windows 3 GB option (see Note 110172).

l Linux: Unlike Windows, in LINUX it is not possible to use the first GB in the address space for shared memories. This means there is a maximum address space of 2 GB for all shared memories. With the following reduced settings vmcj/option/ps = 256M vmcj/option/maxJavaHeap = 100M vmcj/max_vm_heap_MB = 64M and an address space of 512 MB for the extended memory (em/address_space_MB) a maximum of 1016 MB can be used for shared memories. The estimated size of the shared memories that is calculated by sappfpar may therefore comprise a maximum of 1016 MB. Note that in this calculation, the system only takes into account whether the pools are occupied, not the size of the pools. Therefore, if pools are configured larger than is necessary, these deltas must be added to the maximum size of the shared memories or be subtracted from the maximum usable 1016 MB. The attachment to this note contains a document that further clarifies how to use the address space on LINUX.

3) The trace files contain the following error message types: X *** ERROR => Es2CtxAlloc: No free local window slot found [es2xx.c 2763] X *** ERROR => Em2HeapCtxAllocMmResource_ES2: Es2CtxAlloc failed [em2xx.c 3478] X *** WARNING => Em2IHeapCtxRealloc: Out of extended memory, going to PRIV-MODE (ctx=2/sizeKB=65518) [em2xx.c 2312]

Here, the VM in transaction SM52 has the state "sleep" or "unused" and seems to be no longer usable.

The error may occur after one of the following happens:

l Platforms with itanium processors. In this case, the asynchronous run of the JIT compiler requires more memory.

l Memory configurations that exceed a maximum memory requirement of 96G.

As a solution, you should increase the VM heap, for example:

vmcj/max_vm_heap_MB = 128

 

Documentation

the documentation for the VM container is attached to this document in German and English as a PDF document. You can find the latest version of the documentation in the SAP Help Portal at http://help.sap.com as part of the "SAP NetWeaver 2004s" documentation. The documentation contains information about both the architecture and use of the VM Container and its administration tools.

Validity

Software Component From Rel. To Rel. And Subsequent

SAP_BASIS 700 702  

710 730  

731 731  

740 740  

References

This document refers to:

SAP Notes

This document is referenced by:

SAP Notes (11)

1020539   Memory management in the VM container

1014811   SYSTEM_NO_MEMORY with no memory bottleneck

990115   Configuring the shared pool

946763   Large sessions in the VMC

903245   VMC Profile Parameters are not known in RZ10/RZ11

871402   Incorrect activation for transports w/ deleted config.

863354   Using the "VM container" component

855455   Setting up IPC if there is no platform support

844817   Technical information for the VMC based AP 7.00 engines

844816   Information for Upgrade from IPC 4.0 to SAP AP 7.00

110172   Windows: Transactions with large memory requirements

19466   Downloading SAP kernel patches

871402   Incorrect activation for transports w/ deleted config.

844817   Technical information for the VMC based AP 7.00 engines

844816   Information for Upgrade from IPC 4.0 to SAP AP 7.00

1020539   Memory management in the VM container

1014811   SYSTEM_NO_MEMORY with no memory bottleneck

903245   VMC Profile Parameters are not known in RZ10/RZ11

990115   Configuring the shared pool

863354   Using the "VM container" component

855455   Setting up IPC if there is no platform support

946763   Large sessions in the VMC

110172   Windows: Transactions with large memory requirements