Original post: https://blogs.technet.microsoft.com/sbs/2011/07/06/potential-issues-after-installing-sharepoint-foundation-2010-sp1/

Since SharePoint Foundation 2010, patching SharePoint is a two-step process. The updated binaries are first installed and then PSCONFIG must be completed to update the SharePoint databases.

Without completing PSCONFIG, you might experience unexpected SharePoint search failures and all backups may stop working on the affected server.

The Following errors may be found in the server application log:

Log Name: Application
Source: Microsoft-SharePoint Products-SharePoint Foundation Search
Event ID: 70
Task Category: Gatherer
Level: Error
User: CONTOSO\spsearch
Computer: CONTOSO-SERVER.contoso.local
Description:
The mount operation for the gatherer application 37ad8233-57f1-47b1-873e-6a91d0f1bc36 has failed because the schema version of the search administration database is less than the minimum backwards compatibility schema version supported for this gatherer application. The database might not have been upgraded.

Log Name:      Application
Source:        Microsoft-Windows-Backup
Event ID:      521
Level:         Error
User:          SYSTEM
Description:
The backup operation that started at ‘?2011?-?07?-?06T02:12:07.198000000Z’ has failed because the Volume Shadow Copy Service operation to create a shadow copy of the volumes being backed up failed with following error code ‘2155348129’. Please review the event details for a solution, and then rerun the backup operation once the issue is resolved.

 

You can also run the following commands to determine if you need to complete the update process with PSCONFIG:

• Launch an elevated (Run as Administrator) SharePoint 2010 Management shell from start, All Programs, Microsoft SharePoint 2010 Products, SharePoint 2010 Management Shell.
• Once the shell opens, type the following command followed by enter:
  (get-spserver $env:computername).NeedsUpgrade

If the result of this command is True, then you need to complete the steps below. If the result is False then no further action is needed, if you are encountering similar events the cause will most likely not be resolved by the following steps.

 

In order to update the SharePoint databases, you must manually run the PSconfig utility. To run the utility:

1. Open an Administrative command prompt.
2. Change directory to C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\BIN
3. Run PSConfig.exe -cmd upgrade -inplace b2b -force -cmd applicationcontent -install -cmd installfeatures

Note: The Companyweb site will be inaccessible while the command is running. It is best to run the command after business hours. The amount of time the command takes to run will vary on the size of the database and the speed of the machine. On a reference machine with 8 logical processors, 32GB of RAM and a 2GB content database, the command took approximately 5 minutes to execute.