I'm seeing that most of my content is not getting indexed.  I'm seeing the following errors in the crawl log:

The item could not be indexed successfully because the item failed in the indexing subsystem. ( The item could not be indexed successfully because the item failed in the indexing subsystem.; Failed to recover content group; Aborting insert of item in Link Database because it was not inserted to the Search Index.; ; SearchID = 04081656-B51B-4DCD-96D4-6DB2D2CEEEE7 )

as well as these:

The item could not be indexed successfully because the item failed in the indexing subsystem. ( The item could not be indexed successfully because the item failed in the indexing subsystem.; Caught exception when preparing generation GID[7]: (Previous generation (last=GID[6], curr=GID[7]) is still active. Cannot open GID[7]); Aborting insert of item in Link Database because it was not inserted to the Search Index.; ; SearchID = 92EB0180-C086-4853-BED8-F4878D9748AD )

We're running SharePoint 2013 Enterprise on 1 Web Front End and 1 SQL Back End.  All machines are 2012 and SQL is 2012.

Any help would be appreciated.

Hi!

Reset index in Search Service application and run a full crawl. Do you have cumulative updates installed on your SharePoint?

Pavel I just noticed this after doing just that.  I was getting a message about the Index partition being out of whack and so I reset the index and did a full crawl immediately after.

I believe we have cumulative updates installed but I'm not the one who installed SharePoint or last configured it.  Is there an article on how to do that or where to check?

You can check it in Central Administration -> Upgrade and Migration -> Check product and patch installation status. It will show build numbers.

Also pay attention to Central Administration -> Manage Content Databases -> for each database (include Central Administration one) open its properties and check the section "Database Versioning and Upgrade".

here is the best practices to apply CU for the SharePoint farm with Search services.

http://blogs.technet.com/b/tothesharepoint/archive/2013/03/13/how-to-install-update-packages-on-a-sharepoint-farm-where-search-component-and-high-availability-search-topologies-are-enabled.aspx

What happen after the full crawl, same error or fixed? Also make sure Index location has not running out of space.

here is the best practices to apply CU for the SharePoint farm with Search services.

http://blogs.technet.com/b/tothesharepoint/archive/2013/03/13/how-to-install-update-packages-on-a-sharepoint-farm-where-search-component-and-high-availability-search-topologies-are-enabled.aspx

What happen after the full crawl, same error or fixed? Also make sure Index location has not running out of space.

The full crawl completed with ~5000 out of 50,000 items successfully indexed.

Most of them are failing with this message (in bold):

The item could not be indexed successfully because the item failed in the indexing subsystem. ( The item could not be indexed successfully because the item failed in the indexing subsystem.; Failed to recover content group; Aborting insert of item in Link Database because it was not inserted to the Search Index.; ; SearchID = 46A9B657-C382-4D76-BABD-05BF8D76F02F )

A couple of things I'm trying to figure out:
1.  What does 'failed to recover content group mean'?

2.  How would I find out the disk location of the index partition?

More information:

I was incorrect about the full crawl being completed.

Should I disable the continuous crawl for the Local SharePoint sites until the full crawl is completed?

Continuous crawl will not run until finishing of the full crawl so you can be calm about it.

I guess, crawler cannot find item in the index partition while crawler believe the item should be there. To find index partition try:

Get-SPEnterpriseSearchServiceApplication | Get-SPEnterpriseSearchStatus HealthReport Component <your index component name> -Text

As suspected this was a drive space issue.  I found the location of the Index Partition, increased the drive space, reset the index, rebooted the WFE and started a full crawl.

The strange thing is I had plenty of room on the drive.  I only added more disk space to the drive to clear an error indicating that I didn't not have double the amount of RAM on the drive to account for swap, etc.

• Marked as answer by pigjam Thursday, April 24, 2014 7:04 PM

As suspected this was a drive space issue.  I found the location of the Index Partition, increased the drive space, reset the index, rebooted the WFE and started a full crawl.

The strange thing is I had plenty of room on the drive.  I only added more disk space to the drive to clear an error indicating that I didn't not have double the amount of RAM on the drive to account for swap, etc.

• Marked as answer by pigjam Thursday, April 24, 2014 7:04 PM

As suspected this was a drive space issue.  I found the location of the Index Partition, increased the drive space, reset the index, rebooted the WFE and started a full crawl.

The strange thing is I had plenty of room on the drive.  I only added more disk space to the drive to clear an error indicating that I didn't not have double the amount of RAM on the drive to account for swap, etc.

• Marked as answer by pigjam Thursday, April 24, 2014 7:04 PM

As suspected this was a drive space issue.  I found the location of the Index Partition, increased the drive space, reset the index, rebooted the WFE and started a full crawl.

The strange thing is I had plenty of room on the drive.  I only added more disk space to the drive to clear an error indicating that I didn't not have double the amount of RAM on the drive to account for swap, etc.

• Marked as answer by pigjam Thursday, April 24, 2014 7:04 PM

As suspected this was a drive space issue.  I found the location of the Index Partition, increased the drive space, reset the index, rebooted the WFE and started a full crawl.

The strange thing is I had plenty of room on the drive.  I only added more disk space to the drive to clear an error indicating that I didn't not have double the amount of RAM on the drive to account for swap, etc.

• Marked as answer by pigjam Thursday, April 24, 2014 7:04 PM

@Sbetzel did you get this figured out? I don't have a space issue and I am trying to figure out what "name" is my Index server.

Thank you!

Matt