IBM TotalStorage DS6000 Series: Performance Monitoring and Tuning

Chapter 9. Open system servers - Windows 333

For more information, see:

http://www.microsoft.com/windows2000/techinfo/reskit/en-us/regentry/29932.asp

9.4.4 Improve memory utilization of file system cache

This registry entry allows the system to improve memory utilization for the file system cache

and allows for more files to be opened simultaneously on a large system. It can, however,

utilize additional memory from the page pool.

The following steps can be used to add this registry key:

1. Start Registry Editor (Regedit.exe). Locate and select the following Registry subkey in the

HKEY_LOCAL_MACHINE subtree:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory

Management

2. From the Edit menu, click Add Value.

3. Enter UnusedFileCache as the value name and set the Data Type to REG_DWORD.

4. Click OK and enter a value of 0 or 5–40 as the data.

– 0: Default behavior similar to Windows NT 4.0 Service Pack 3.

– 5–40: Trim unused file cache based on pool usage.

• The value being set represents the percent of pool that we allow to be consumed by

unused segments, where 5 is most aggressive (for example, it increases the size of

the cache the least), and 40 is least aggressive (for example, it lets the cache grow

to the largest before trimming).

• Testing performed by Microsoft found that this registry change has positive benefits

in that it also increases the performance of some applications such as IIS. It works

best when set to 15–20. Do not choose a value greater than 20 without extensive

stress testing.

Click OK, quit Registry Editor, and then shut down and restart the computer.

9.5 Host bus adapter (HBA) settings

On Windows, the following HBAs are supported to connect the DS6000 to your servers.

򐂰 Emulex

– LP9002L

– LP9002DC

– LP9402DC

–LP9802

– LP10000

– LP10000DC

2 GB 0x80000000

4 GB 0xFC000000

8 GB 0xFFFFFFFF

Physical RAM IoPageLockLimit setting (Hex)