In order to fix issues with index volumes that report errors in Compliance Accelerator (CA) or Discovery Accelerator (DA) searches, the proper information for the problem index volume(s) must be obtained.  To identify the needed information for the affected index volume(s), a SQL query must be run against the EnterpriseVaultDirectory database using information from within the Search Details panel of the Searches pane in the CA or DA Client.

1. Obtain the Index Volume ID for each index volume showing an error (i.e., "The search could not be performed due to the index not being searchable.", "Archive and index out of sync.").  Note that the Info column entry of 'Date range exclusion" is not an error message but an information message informing the user that the index volume was skipped as it did not contain any items within the date span of the search.
   1. Open the CA or DA Client, if not already open.
   2. Navigate to the Cases (for DA) or Departments (for CA) tab.
   3. Click in the left pane on the name of the Case or Department in which the search was run.
   4. After the focus in the right pane changes to show information about the Case or Department selected in the left pane, click on the Searches tab.
   5. Click on the name of the search with index volumes that failed to be searched due to an error.
   6. Click on the Show: field drop down arrow to display the listing of available display options in the Search Details panel.
   7. Select the option 2000 failed/error archive indexes.
   8. Note the Index Volume ID column entries for each failed index volume.
2. Using an account with sufficient SQL permissions to read the data in the CA or DA customer database, launch SQL Server Management Studio.
3. Log onto the SQL Server \ instance hosting the CA or DA customer database.
4. Open a New Query window focused on the CA or DA customer database.
5. Run the following SQL query against the EnterpriseVaultDirectory database, repeatedly replacing #IndexVolumeID with each of the Index Volume ID valued noted in Step 1.h before executing the query: 

Note: Update Index Volume ID from DA Search Details where indicated.

DECLARE @FailedIndex AS NVARCHAR(100)

SET @FailedIndex = #IndexVolumeID --<<< replace #IndexVolumeID with the Index Volume ID from CA or DA Search Details noted in Step 1.h.

SELECT a.ArchiveName
     , a.ArchiveDescription
     , iv.IndexVolumeIdentity
     ,DATEADD(mi, DATEDIFF(mi, GETUTCDATE(), GETDATE()), iv.YoungestItemDateUTC) AS 'Youngest Archived Item'
     , DATEADD(mi, DATEDIFF(mi, GETUTCDATE(), GETDATE()), iv.OldestItemDateUTC) AS 'Oldest Archived Item'
     , iv.FirstItemSequenceNumber AS 'First Item Sequence Number'
     , irpe.IndexRootPath
     , iv.FolderName
FROM Archive AS a
JOIN IndexVolume AS iv
  ON a.RootIdentity = iv.RootIdentity
JOIN IndexRootPathEntry AS irpe
  ON iv.IndexRootPathEntryID = irpe.IndexRootPathEntryID
WHERE iv.IndexVolumeIdentity = @FailedIndex

The First Item Sequence Number is the starting value of the index volume when shown in the Vault Admin Console display of the archive's Properties in the Index Volumes tab, Details button.  The First Item Sequence Number will be shown as the first number in the Range column for the matching index volume.  Once the First Item Sequence Number for each affected index volume has been obtained, the appropriate action can be taken against the index volume(s) to resolve the search issue.