I have previously merged multiple v4 indexes together with no issues (ie. http://wiki.splunk.com/Community:MoveIndexes - Last updated 18th April 2013.).
My question is, are there any v5 specific issues or updates tasks required? Note: Our v5 indexers are not clustered at all yet so bucket renumbering tasks remains the same as with a v4 merge.
I noticed that v5 indexes have a "indexname.dat" file that simply contains the next hotbucket number. Does this need to be deleted or manually updated, in a similar fashion to how the manifests should be deleted, so that upon splunk start up they recreated using the combined buckets?