RavenDB on IIS: Cannot access file, the file is locked or in use

I came across another issue with trying to get RavenDB working through IIS. When the process started up I got the error message “Cannot access file, the file is locked or in use”.

The stack trace looked like this:

[EsentFileAccessDeniedException: Cannot access file, the file is locked or in use]
   Microsoft.Isam.Esent.Interop.Api.Check(Int32 err) in C:\Work\ravendb\SharedLibs\Sources\managedesent-61618\EsentInterop\Api.cs:2736
   Raven.Storage.Esent.TransactionalStorage.Initialize(IUuidGenerator uuidGenerator) in c:\Builds\RavenDB-Stable\Raven.Storage.Esent\TransactionalStorage.cs:205

[InvalidOperationException: Could not open transactional storage: C:\inetpub\ravendb\Data\Data]
   Raven.Storage.Esent.TransactionalStorage.Initialize(IUuidGenerator uuidGenerator) in c:\Builds\RavenDB-Stable\Raven.Storage.Esent\TransactionalStorage.cs:220
   Raven.Database.DocumentDatabase..ctor(InMemoryRavenConfiguration configuration) in c:\Builds\RavenDB-Stable\Raven.Database\DocumentDatabase.cs:185
   Raven.Web.ForwardToRavenRespondersFactory.Init() in c:\Builds\RavenDB-Stable\Raven.Web\ForwardToRavenRespondersFactory.cs:84
   Raven.Web.RavenDbStartupAndShutdownModule.b__0(Object sender, EventArgs args) in c:\Builds\RavenDB-Stable\Raven.Web\BootStrapper.cs:13
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +80
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +270M

It turns out that I hadn’t given the account IIS was using access to the directory… Or rather, I had given access, I just didn’t tell IIS about the account so it was using the default account.

To fix the issue:

• Go into the Application Pools section of IIS.
• Click the Application pool used by the RavenDB site
  
  
• Press “Advanced Settings…” on the right side of the dialog.
• Ensure the correct account is set up for the “Identity” in the “Process Model” section.
  
  
• Once you’ve set up the correct user, press "OK" for each of the dialogs and everything should be ready.