how to increase SCCM client logs file size

By default sccm client log files have default size of 250000 bytes in Decimal (3d090 in Hexa Decimal) which is around 245 KB in Decimal which you can see it from your sccm client computer registry
Registry path would be HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\CCM\Logging\@GLOBAL on 32 Bit OS
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\CCM\Logging\@GLOBAL on 64 Bit OS

If you want to trace previous data about program executions or patch updates from updateddeployment.log or inventory.log or something else from sccm client log files
you can increase it to required value.
Note: Doing this process will change the size of all sccm client log files not particular log file.

How to change this Value:

1.Type Regedit from your command prompt
2.drill down to the said path below:

On Windows 32 Bit OS:HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\CCM\Logging\@GLOBAL
On Windows 64 Bit OS:HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\CCM\Logging\@GLOBAL

You will see registry value called LogMaxSize with size of 3d090 (Hexa) and in Decimal it is 250000.
The above value is in Bytes. Conversion of 250000 bytes into KB is 245 KB.

So i would change this value to 3 MB or so in bytes it is 3145728 Bytes and in Hexa Decimal :300000
Have used conversion meter from Mega Bytes to Bytes http://www.calculateme.com/ComputerStorage/Megabytes/ToBytes.htm.

Hope it Helps!

To change this on bulk number of machines you can use the below VB script and run it using SCCM or Psexec.

Option Explicit

Dim WSHShell, RegKey ,strcomputer

strComputer = "."

set WSHShell = CreateObject("WScript.Shell")

RegKey = "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\CCM\Logging\@GLOBAL\"

WSHShell.RegWrite RegKey & "LogMaxSize", 3145728, "REG_DWORD"

If you are installing SCCM client newly on system and if you need to have sccm clients log size more that is avilable by default, you can use CCMLOGMAXSIZE command line syntax like below :

CCMSetup.exe CCMLOGMAXSIZE=300000 refer http://technet.microsoft.com/en-us/library/bb680980.aspx

Reference :

SetGlobalLoggingConfiguration Method in Class SMS_Client http://msdn.microsoft.com/en-us/library/cc146025.aspx

SMS_Client Client WMI Class http://msdn.microsoft.com/en-us/library/cc146352.aspx