Improve LinstorSR.py to handle thick SR creation (#85)

Check enabled hosts instead of online during SR creation

Added `get_enabled_hosts` to get enabled hosts during SR operations. In some drivers e.g. LINSTOR, we need to ensure that hosts are enabled before performing operations, hence this function is needed. In some cases `thick` SR creation may fail due to `get_online_hosts` as the metrics could take time.

Signed-off-by: Rushikesh Jadhav <[email protected]>

Author: rushikeshjadhav

drivers/LinstorSR.py

@@ -586,7 +586,7 @@ def create(self, uuid, size) -> None:
                 opterr='LINSTOR SR must be unique in a pool'
             )
 
-        online_hosts = util.get_online_hosts(self.session)
+        online_hosts = util.get_enabled_hosts(self.session)
         if len(online_hosts) < len(host_adresses):
             raise xs_errors.XenError(
                 'LinstorSRCreate',

drivers/util.py

@@ -777,6 +777,11 @@ def get_slaves_attached_on(session, vdi_uuids):
     master_ref = get_this_host_ref(session)
     return [x for x in host_refs if x != master_ref]
 
+def get_enabled_hosts(session):
+    """
+    Returns a list of host refs that are enabled in the pool.
+    """
+    return list(session.xenapi.host.get_all_records_where('field "enabled" = "true"').keys())
 
 def get_online_hosts(session):
     online_hosts = []