What is the search Index file location?

Question

Our company is running SP2013 on-premise. According to some articles, the search index files are stored at C:\Program Files\Microsoft Office Servers\15.0\Data\Office Server\ by default.

On the WFE server, we checked above path only contain 1GB data. However, when we perform index reset, about 7-8GB space is released in C drive. So where is the files hided?

I tried following PowerShell:

$ssa = Get-SPServiceApplication -name "Search Service Application"
$active = Get-SPEnterpriseSearchTopology -SearchApplication $ssa -Active
Get-SPEnterpriseSearchComponent -SearchTopology $active

The RootDirectory is null. How come?

Answer 1

Null root directory is OK, it designates the default index location. Once you for example relocate the index, it will be assigned the new directory name.

Logically, to restore the default index location, you can run New-SPEnterpriseSearchIndexComponent commandlet without having to specify -RootDirectory property.

Answer 2

To find the exact location of the search index, I suggest to use this script instead of the version you tried:

$essi = Get-SPEnterpriseSearchServiceInstance
$cc = $essi.Components | ? { $_.GetType().Name -eq 'CrawlComponent' }
$cc.IndexLocation

You might have an empty RootDirectory and having your index files at other (not default) location, for example, if you installed SharePoint on another drive / folder. I assume RootDirectory empty means: the standard location below this installation path.

See the InstallPathRoot key at registry hive HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office Server\15.0 for the path of the installation.