paging space not getting released in our dia instance ECC / DB2 / AIX 6

[Former Member]

Hi

We are running SAP ECC 6.0 EHP IV / DB2, Kernel version given below.

Application Server e1pdi1_E1P_13

SAP Kernel Information

SAP Kernel : 701_REL

Database Client Library : DB6_81

created in : AIX 2 5 00CB5A5B4C00

created on : Feb 24 2009 21:47:02

Support Level : 0

Kernel Patch number : 32

Source ID : 0.032

DBSL Patch No. : 021

ICU Version : 3.0 Unicode Version 4.0.1

libsapu16 Version : 1.0025 Feb 20 2009 21:14:07

In our dialog instance, the paging space is not getting released it

grows daily, we had to restart the dialog instances to reduce the

paging space ususage.

Even though memory utilization is around 50%, paging space utilization

on the dialog instance is at approx 80% currently.

│ Memory

───────────────────────────────────────────────────────────────────────────────────

───────────│

│ Physical PageSpace | pages/sec In Out |

FileSystemCache │

│% Used 54.0% 79.5% | to Paging Space 0.0 0.0 |

(numperm) 3.5% │

│% Free 46.0% 20.5% | to File System 0.0 0.0 |

Process 37.9% │

│MB Used 11617.9MB 17095.2MB | Page Scans 0.0 |

System 12.7% │

│MB Free 9886.1MB 4408.8MB | Page Cycles 0.0 |

Free 46.0% │

│Total(MB) 21504.0MB 21504.0MB | Page Steals 0.0

| -

---

│

│ | Page Faults 374.0 |

Total 100.0% │

│----

---

|

numclient 3.5% │

│Min/Maxperm 623MB( 3%) 18689MB( 87%) <--% of RAM |

maxclient 86.9% │

│Min/Maxfree 960 1088 Total Virtual 42.0GB |

User 38.3% │

│Min/Maxpgahead 2 8 Accessed Virtual 25.6GB 60.9%|

Pinned 11.3% │

│──────────────────────────────────────────────────────────────────────────────────

────────────────────│

│

│

We also logged into SAP and found that most of the diag and backgroup

wp are free and not much users logged in.

Can you please let us know what needs to be done, so that we don't have

to restart our dialog instance frequently

Thanks & Regards

Senthil

[Former Member · Accepted solution]

Hi Senthil,

If you have problem that "memory is not getting released by WPs" So will you please esnure that you have all the SAP recommanded AIX related parameters in Place. Please refer to below note for more details.

"Note -1048686 - Recommended AIX settings for SAP"

Please note that when you restart your SAP system.

The release of memory for the operating system can be activated by the following parameters:

es/disclaim_threshold_MB (default: 0, ineffective) - specifies the threshold above which memory is released for the operating system)

es/disclaim_coasting_time_alloc (default: 0, inactive)

es/disclaim_coasting_time_free (default: 0, inactive) specifies the coasting time in seconds, how long after the threshold has been exceeded memory below the threshold is also freed up for allocation to or release from the operating system.

es/blockdisclaimsize_KB (default: 0, inactive) This parameter specifies in kilobytes the size of the upper part of an EM block that is also released for the operating system. It combines the benefit of smaller EM blocks (em/blocksize_KB) with regard to the main memory requirement, with the benefit of larger EM blocks with regard to performance.

es/freelist_compactor (default: 1) should not be 0, so that the process described above can be fully effective.

refer to below link for more information

http://help.sap.com/saphelp_nw04/helpdata/en/f6/3e63cd45bc4d6d80c4ee45d12f9884/content.htm

Thanks,

Arjun

[former_member204080]

Hi,

Check this note

Note 78498 - High paging rate on AIX servers, in particular DB servers