Configuration of svservice

The svservice component of App Volumes agent is used for communicating system events, such as computer startup, login, logout, and shutdown, with the App Volumes Manager. You can configure this component with registry keys at HKLM\SYSTEM\CurrentControlSet\Services\svservice\Parameters.

Parameters for configuring svservice

If a backup svservice log file meets either of these policy rules, the log file is deleted:

If the aggregate size of all the backup log files is greater than a designated number, then svservice starts the deletion from the oldest backup log file until the aggregate size is lower than the designated number.
To set the designated aggregate size of all backup log files, you can use the BackupLogFileSizeInKB parameter.
If a backup log file is older than the designated number of days, the log file is deleted.
To designate the number of days for the log deletion policy, you can use the BackupLogFileDays parameter.


Parameter	Type	Description
BackupLogFileSizeInKB	REG_DWORD	The aggregate size of all svservice backup log files. If the aggregate size of all backup log files is greater than the value of this parameter, svservice starts the deletion from the oldest backup log file until the aggregate size is lesser than the value of this parameter. The default value of this parameter is `768000 (750MB)` and the maximum value is `3584000 (3500MB)`. Note: If the parameter is set to `0` or greater than the maximum value, svservice uses the default value as the value of this parameter.
BackupLogFileDays	REG_DWORD	The maximum age of svservice backup log files. If an svservice backup log file is older than the value of this parameter, the backup log file is deleted. The default value of this parameter is `15 days`.
CaptureFTA	REG_DWORD	When this parameter is activated, file type association metadata is captured during packaging the application. To deactivate the capture of metadata, value of this parameter must be set to `0` in the packaging virtual machine before packaging the application. By default, this parameter is activated and file type association metadata is captured.
CleanSystemWritable	REG_DWORD	Use this parameter to either allow svservice to clear any changes made on the system Writable Volume or retain the changes after a restart. If set to `1`, system Writable Volume is cleared after a restart. If set to `0`, system Writable Volume is not cleared after a restart and the changes are retained. By default, the value of this parameter is `0`. Location of the system Writable Volume is C:\{00000000-0000-0000-0000-000000000000}.
CommandLineAppDelivery	REG_DWORD	Allows real time delivery of an application package to an end user using command-line options in App Volumes agent. Supported values of the registry key are `0` and `1`. By default, the value of the key is `1` (enabled). For an understanding of the command-line delivery behavior, see Command-line Delivery of Applications in App Volumes.
ConnectTimeOutMs	REG_DWORD	Defined in milliseconds for server connection requests. If a connection request takes longer than this timeout value, the request is canceled. The default is 10 seconds.
DelayVirtualizationType	REG_DWORD	Defers application virtualization at end user login and helps in improving the user login time. Values of this parameter are as follows: `0` - Applications are virtualized (enabled for end user) as soon as the end user enters the login credentials. `1` - Applications are virtualized after the end user enters the login credentials. `2` - Applications are virtualized just before the desktop is visible to the end user. `3` - Applications are virtualized a few seconds after the desktop is visible to the end user. The default value of this parameter is `2`.
DeliverAppsAtLogin	REG_DWORD	Use this parameter to skip delivery of applications at login. This parameter can be used on computers that receive on demand delivery when user assignments already exist for other computers on the same App Volumes Manager. By default, this parameter defaults to `1` and applications are delivered to the end user during login. To use this parameter, an administrator must manually add this parameter to svservice. If the value of this parameter is set as `0`, applications are not delivered to the end user at login. If the parameter has a non-zero value, then applications are delivered to the user at login. For more information about the package delivery modes, see Understanding Package Delivery Modes in App Volumes. For information about published applications on demand delivery, see Configure Horizon 8 for Published Applications on Demand Delivery section in the Windows Desktops and Applications in Horizon 8.
DisableAutoStartServices	REG_DWORD	Use this parameter to not start services automatically when application virtualization starts. If set to `1`, when application virtualization starts, services belonging to the application do not start automatically. By default, the value of this parameter is `0`.
DisableRunKeys	REG_DWORD	Use this parameter to deactivate Run key execution. If set to `1`, the application's Run key entries do not start automatically. By default, the value of this parameter is `0`.
DisableAppServicesList	REG_DWORD	Application services added to this multi-string registry key are not started when the application package is virtualized. This parameter is located at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\svservice\Parameters.
DriveLetter	REG_SZ	To assign a specific drive letter to a Writable Volume, use this parameter. Note: To use this parameter, ensure that you have configured DriveLetterSettings to `DRIVELETTER_ASSIGN_WRITABLE`. DriveLetterSettings is an svdriver parameter. For more information about the registry value, see the Driver Letter Settings in Configuration of svdriver. A Writable Volume can have any drive letter from `C:` to `Z:`. The allowed formats for a drive letter are as follows: `"E"`, `"E:"`, `"e"`, or `"e:"`. The drive letter of a Writable Volume can be updated. For example: A Writable Volume is assigned a drive letter, `D:`. Use this parameter to assign the drive letter, `E:`. As a result, the drive letter for the Writable Volume is updated from `D:` to `E:`. If no drive letter is assigned, App Volumes assigns any available drive letter to the Writable Volume, starting from `C:`.
DomainNameWaitTimeOut	REG_DWORD	Defined in seconds how long to wait for the computer during startup to resolve Active Directory domain name. On machines that are not joined to any domain, you can set the value to 1 for faster login. The default is 60.
HidePopups	REG_DWORD	Use this parameter to hide pop-up messages displayed by svservice. If set to `1`, svservice.exe does not display pop-up messages. By default, the value of this parameter `0`.
LogFileSizeInKB	REG_DWORD	The size of the log file before rotating the log file. The default value of this parameter is `15360MB (15MB)` and the maximum value of this parameter is `51200 (50MB)`. Note: If the parameter is set to a value greater than the maximum value or `0`, svservice uses the default value as the value of this parameter.
MaxDelayTimeOutS	REG_DWORD	The maximum wait for a response from the App Volumes Manager, in seconds. If set to 0, the wait for response is forever. The default is 300 seconds (5 minutes).
ProvisioningCompleteTimeOut	REG_DWORD	Defined in seconds to keep trying to contact the App Volumes Manager after provisioning is completed. The default is 120.
RebootAfterDetach	REG_DWORD	Use this parameter to automatically restart the agent computer after the end user logs out. If set to `1`, the agent computer restarts automatically after the end user log out. By default, the value of this parameter is `0`.
ResolveTimeOutMs	REG_DWORD	Defined in milliseconds for name resolution. If resolution takes longer than the timeout value, the action is canceled. The default is 0, which waits for completion.
ReceiveTimeOutMs	REG_DWORD	Defined in milliseconds to receive a response to a request. If a response takes longer than this timeout value, the request is canceled. The default is 5 minutes.
SendTimeOutMs	REG_DWORD	Defined in milliseconds for sending requests. If sending a request takes longer than this timeout value, the request is canceled. The default is 30 seconds.
VolumeExpansionTimeoutInMs	REG_DWORD	Specifies the maximum time, in milliseconds, svservice waits for the diskpart command to expand a Writable Volume and then times out. The default value of this parameter is `60000ms` and this parameter can be configured to override the default value.
WaitInstallFonts	REG_DWORD	Defines how long to wait in seconds for fonts to be removed. The default is to not wait for completion.
WaitUninstallFonts	REG_DWORD	Defines how long to wait in seconds for fonts to be removed. The default is to not wait for completion.
WaitForFirstVolumeOnly	REG_DWORD	Defined in seconds, only hold logon for the first volume. After the first volume is complete, the remaining are handled in the background, and the logon process is allowed to proceed. To wait for all volumes to load before releasing the logon process, set this value to 0. The default is 1. Note: When WaitForFirstVolumeOnly parameter is set to `0`, svservice implicitly sets the DelayVirtualizationType parameter value to `0`.