Change Default Index File Location

In a farm environment it will be usually a requirement to have the index file location on a separate drive and folder as opposed to the default location which is:

"C:\Program Files\Microsoft Office Servers\12.0\Data\Office Server\Applications"

You can set this path for an SSP by using the UI through Central Administration. But to set the default path for Office SharePoint Server Search Service and for WSS Search Service you will have to set the location through STSADM command.

Office SharePoint Server Search Service is configured using OSEARCH command:

If its not clear then read here:
stsadm -o osearch -defaultindexlocation e:\Data\MOSS_Search_Index

(By default, the search index will be located at this path on this server. For index servers, you can specify a different path when you create an SSP.

Note:
Changing the index location will reset the index. To move an index with a reset, use the noreset parameter of the Spsearchsensitive or Osearchsensitive operation)

Windows SharePoint Services Search Service is configured using SPSEARCH command:

If its not clear then read here:
stsadm -o spsearch -indexlocation e:\Data\MOSS_Search_Index

(Configures the search server that has the location of where the index resides)

You can also set this path for already created SSP using EDITSSP command:

If its not clear then read here:

stsadm -o editssp -title Sharedservices1 -indexlocation e:\Data\MOSS_Search_Index

(Configures the search server that has the location of where the index resides. This parameter is used in conjunction with the osearch operation. )

References:

SPSEARCH: http://technet.microsoft.com/en-us/library/cc288507.aspx

OSEARCH: http://technet.microsoft.com/en-us/library/cc262920.aspx

EDITSSP: http://technet.microsoft.com/en-us/library/cc262727.aspx