When I ran the SolrCloud (6.3.0) Back API using this url backup url
It returns response status 0 i.e no error
<?xml version="1.0" encoding="UTF-8"?>
<response>
<lst name="responseHeader">
<int name="status">0</int>
<int name="QTime">213</int>
</lst>
<lst name="success">
<lst name="localhost:8983_solr">
<lst name="responseHeader">
<int name="status">0</int>
<int name="QTime">43</int>
</lst>
</lst>
</lst>
</response>
But I didn't find any locations_back folder with backed up data on my system.
When I ran this curl from command line, it returns some numbers like 32058, 32059,32060 etc.
curl http://localhost:8983/solr/admin/collections?action=BACKUP&name=locations_back&collection=locations&location=/opt/solr/server/solr
[1] 32058
[2] 32059
[3] 32060
Where I tested with location param path location=/opt/solr/server/solr OR location =/
But It also didn't show any locations_back folder with backed up data on my system.