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  • You are running Windows Server 2003 or Windows XP

AND one or more of the following occurs

  • Backups failed with an error. 
    • The actual error can vary. The most frequent are:
      • Disk Full
      • Cannot Create Archives
      • Cannot Create Archive
      • VSS Snapshot Deleted
      • VSS Snapshot Failed
  • The error Insufficient system resources exist to complete the requested service is logged in LogFile.txt or ZIBLogFile.txt.
    • ZCB logs are located in the \Debug\ folder of your ZCB installation folder.
  • Events are logged in your Application or System events that reference "paged pool memory".
    • Common event numbers include
      • 2020 from source VolSnap
      • Event 5 from source VSS

What's going on?

The system has likely run out of paged pool memory to use for backups. This is a known issue with VSS-based backups on server 2003 machines. Windows XP machines occasionally face it as well, but it is rare.

Microsoft has released multiple updates to address this issue over the years. However, it still happens on some machines.


First, make sure that all available Windows Updates have been applied.

If Windows is up to date, we must increase the paged pool memory allotted to the system. The following instructions are taken directly from this Microsoft Knowlegebase Article.

  1. Start Registry Editor (Regedt32.exe).
  2. Locate and then click the following key in the registry:
    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Memory Management
  3. On the Edit menu, click Add Value, and then add the following registry value:
    Value name: PoolUsageMaximum
    Data type: REG_DWORD
    Radix: Decimal
    Value data: 60

    Setting the value at 60 informs the Memory Manager to start the trimming process at 60 percent of PagedPoolMax rather than the default setting of 80 percent. If a threshold of 60 percent is not enough to handle spikes in activity, reduce this setting to 50 percent or 40 percent.

    Value name: PagedPoolSize
    Data type: REG_DWORD
    Radix: Hex
    Value data: 0xFFFFFFFF

    Setting PagedPoolSize to 0xFFFFFFFF allocates the maximum paged pool in lieu of other resources to the computer.

    If you cannot enter the "x" character, enter just FFFFFFFF

    Caution The 0xFFFFFFFF PagedPoolSize setting is not recommended for use on 32-bit Windows Server 2003-based computers that have 64GB of RAM. This will potentially bring the Free System PTE entry down and can cause continuous reboot of the computer. For this configuration, carefully choose a value based on the requirements and available resources.

  4. Quit Registry Editor.
  5. Restart the server for the changes to take effect.