StableBit DrivePool Advanced Settings

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You can tweak advanced settings in DrivePool by editing a .config file in notepad.

The file is located in C:\Program Files\StableBit\DrivePool\DrivePool.Service.exe.config_default or C:\Program Files\StableBit\DrivePool\DrivePool.Service.exe.default.config on the server.

In order to put the file into effect, you will need to rename it to DrivePool.Service.exe.config and restart the server (or just restart the StableBit DrivePool system service).

Any time you upgrade, or reinstall DrivePool, it writes an updated "default" config file, but leaves the current "DrivePool.Service.exe.config" alone so it doesn't alter any of your settings.

Editing the config file

Open the file in notepad. You will see an XML formatted file. If you're not familiar with XML then all that you need to know is that the values that you can change look like this:


You can change this line to:


The setting name is right above that line:

<setting name="CoveFsLogSizeMB" serializeAs="String">

In this case the name is CoveFsLogSizeMB.

There are also numerical values and time values.


  • CoveFs_AsyncCriticalThreads - How many threads to use for critical asynchronous tasks. Asynchronous tasks are used throughout CoveFS to parallelize various file system operations. In particular, this affects how many disks in the pool are accessed at the same time when we need to query all the disks for some information.
  • CoveFs_AsyncNormalThreads - How many threads to use for normal asynchronous tasks.
  • CoveFs_BoostNetworkIoPriorityWrite - Boost the priority of write network I/O.
  • CoveFs_OpenByFileId - Open by file ID support. This allows applications to open any file on the pool by its unique file ID, instead of the file name. This feature is required by the NFS server. When enabled, the pool will keep track of every file ID that it gives out in pagable memory (memory that is saved to disk and loaded as necessary).
  • CoveFs_Oplocks - Enable / disable file system oplock support.
  • CoveFs_ReadStripingBlockMode - Switch to the read striping block mode algorithm when sequential read access is used.
  • CoveFs_ReadStripingBlockModeNoCache - Disable the NT read ahead cache when using read striping block mode.
  • CoveFs_ReadStripingStripeSize - The stripe size to use for reading in block mode.
  • CoveFs_ReportAsNtfs - Report as "NTFS" to most applications that ask.
  • CoveFs_SynchronizeDirectoryTimes - On NTFS, when creating a new file in a directory, the last write time of the directory that contains that file gets updated. In order to have CoveFS ensure that directory modification times are updated consistently, this needs to be enabled. There is a small real-time performance penalty for having this enabled. The algorithm that makes this work is multi-threaded and will benefit from multiple CPU cores.
  • CoveFs_WaitForVolumesOnMount - Some volumes arrive late in the boot process so DrivePool will wait for all the volumes to arrive before allowing the pool drive to mount. The delay is adaptive, so it will be different for each system. Turning this off might shorten boot times, but is not recommended because it could expose a partially populated pool drive to system services that start right after booting.
  • CoveFs_WaitForVolumesOnMountMs - How long to wait for all the volumes to arrive in MS.


  • DrivePool_BackgroundTasksVeryLowPriority - Sets the CPU priority of background tasks such as re-measuring, background duplication and re-balancing to IDLE (Windows Priority 1). Note that this setting does not affect I/O priority which is set separately.
  • DrivePool_VerifyAfterCopy - After performing a file copy (or move), verify that the destination file was copied successfully by comparing it with the source.

File Balance

  • FileBalance_BackgroundIO - Use background I/O for re-balancing the pool.
  • FileBalance_CalculateRatioForceByteDelta - How many bytes have to be processed by the pool before the ratio is recalculated. The ratio calculation involves no I/O, is done asynchronously and does not block the pool.
  • FileBalance_DuplicationObstructionLimitRatio - Internal variable that controls balance ratio calculation.
  • FileBalance_EvacuationPadding - When evacuating a disk (i.e. re-balancing to move all the files off of it), we pad the amount selected to move off by the ratio of the amount of free space on the target. This is that ratio which is a value from 0.0 to 1.0.

File Duplication

  • FileDuplication_AlwaysRunImmediate - If DrivePool detects that a file is not duplicated, or it's duplicated where it shouldn't be, a duplication pass will start immediately if this is set to True.
  • FileDuplication_BackgroundIO - Use background I/O for background file duplication.
  • FileDuplication_DuplicateTime - The time of day when files will be duplicated, if real-time duplication is disabled.
  • FileDuplication_MaximumPathDepthForEstimation - This is the maximum path depth that background duplication will traverse to estimate the number of folders on the pool that it needs to work on. Increasing this value will increase the delay at the start of background duplication before it starts doing actual work, but will provide more resolution in the completion percentage reported in the Dashboard.


  • BitLocker - Set to True to add support for BitLocker encrypted pool parts. Adds a small overhead and is Disabled by default.
  • CoveFsDebugOutput - Put the kernel driver into debug mode. This should be set to False.
  • CoveFsLogSizeMB - The binary kernel log size. 100MB can be from a few minutes to 10 minutes worth of logs, depending on I/O activity. The kernel binary log records every operation on the pool in a high performance and compact log file.
  • CoveFsTracingEnabled - Enable user / kernel logging by default. This should be left set to True for the BETA, just in case you run into problems and need to submit logs.
  • ErrorReportingOverride - Automatically send error reports to Covecube.

Remove Drive

  • RemoveDrive_PoolReadOnly - Make unduplicated folders on the pool read-only while a disk is being removed. Duplicated folders are always made read-only to preserve data integrity.

Running File

  • RunningFile_FileName - When specified, a file at this path will be created whenever DrivePool is performing a background task, such as re-balancing. After all background tasks complete, this file will be deleted. The folder must already exist for the file.

WHS Command

  • WhsCommand_TimeoutMS - How long to wait for WSS to respond when issuing command to it. If your server is slow and you're getting errors such as Cannot retrieve WHS folders you may want to increase this time. The value is in milliseconds. For 2 minutes you would set this to 120000. Starting with build 5380 this is only applicable for the M3 to M4 migration process.
  • WhsCommand_NoMissingDiskAlert - Do not issue the missing disk alert.

Don't forget to rename the config file after you make the change and restart the server (or service), as noted at the top of this page.