diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal.hs
index e609aa40..99003b54 100644
--- a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal.hs
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal.hs
@@ -73,7 +73,8 @@ ncqStorageOpen3 fp upd = do
   ncqOnRunWriteIdle <- newTVarIO none
   ncqSyncNo         <- newTVarIO 0
   ncqState          <- newTVarIO mempty
-  ncqStateKey       <- newTVarIO mempty
+  ncqStateKey       <- newTVarIO (FileKey maxBound)
+  ncqStateUse       <- newTVarIO mempty
   ncqServiceSem     <- atomically $ newTSem 1
 
   let ncq = NCQStorage3{..} & upd
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Index.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Index.hs
index 685f6bed..da3f01d3 100644
--- a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Index.hs
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Index.hs
@@ -90,7 +90,6 @@ ncqIndexFile n fk = runMaybeT do
   ncqStateUpdate n do
     ncqStateAddIndexFile ts fki
     ncqStateAddDataFile (coerce fk)
-    ncqStateAddFact (FI fk (IndexFile fki))
     ncqStateDelFact (P (PData fk 0))
 
   (bs,nw) <- toMPlus midx
@@ -111,6 +110,8 @@ ncqIndexCompactStep :: MonadUnliftIO m
                     -> m Bool
 ncqIndexCompactStep me@NCQStorage3{..} = flip runContT pure $ callCC \exit -> do
 
+  debug "ncqIndexCompactStep"
+
   idx <- readTVarIO ncqState
            <&> fmap (IndexFile . snd) . ncqStateIndex
 
@@ -150,6 +151,7 @@ ncqIndexCompactStep me@NCQStorage3{..} = flip runContT pure $ callCC \exit -> do
   fki <- ncqGetNewFileKey me IndexFile
   mv result (ncqGetFileName me (IndexFile fki))
 
+  debug $ "state update" <+> pretty a <+> pretty b <+> "=>" <+> pretty fki
   ncqStateUpdate me do
     ncqStateDelIndexFile (coerce a)
     ncqStateDelIndexFile (coerce b)
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/MMapCache.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/MMapCache.hs
index b3cab583..0ba2e8ae 100644
--- a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/MMapCache.hs
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/MMapCache.hs
@@ -52,20 +52,17 @@ ncqGetCachedIndex ncq@NCQStorage3{..} =
         Nothing -> throwIO $ NCQStorageCantMapFile path
         Just (bs, nway) -> pure (CachedIndex bs nway)
 
-ncqDelCachedIndex :: forall m . MonadUnliftIO m
-                  => NCQStorage3
-                  -> FileKey
-                  -> m ()
+ncqDelCachedIndexSTM :: NCQStorage3
+                     -> FileKey
+                     -> STM ()
 
-ncqDelCachedIndex NCQStorage3{..} fk =
-  atomically (modifyTVar ncqMMapCachedIdx$ HPSQ.delete fk)
+ncqDelCachedIndexSTM NCQStorage3{..} fk =
+  modifyTVar ncqMMapCachedIdx$ HPSQ.delete fk
 
+ncqDelCachedDataSTM :: NCQStorage3
+                    -> FileKey
+                    -> STM ()
 
-ncqDelCachedData :: forall m . MonadUnliftIO m
-                  => NCQStorage3
-                  -> FileKey
-                  -> m ()
-
-ncqDelCachedData NCQStorage3{..} fk =
-  atomically (modifyTVar ncqMMapCachedData $ HPSQ.delete fk)
+ncqDelCachedDataSTM NCQStorage3{..} fk =
+  modifyTVar ncqMMapCachedData $ HPSQ.delete fk
 
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Run.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Run.hs
index e62d0711..98b8713b 100644
--- a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Run.hs
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Run.hs
@@ -13,6 +13,7 @@ import HBS2.Storage.NCQ3.Internal.MMapCache
 
 
 import Control.Monad.Trans.Cont
+import Control.Monad.Trans.Maybe
 import Network.ByteOrder qualified as N
 import Data.HashSet qualified as HS
 import Data.HashPSQ qualified as PSQ
@@ -20,6 +21,7 @@ import Data.Vector qualified as V
 import Data.HashMap.Strict qualified as HM
 import Data.ByteString qualified as BS
 import Data.Sequence qualified as Seq
+import Data.Fixed
 import System.FilePath.Posix
 import System.Posix.Files qualified as Posix
 import System.Posix.IO as PosixBase
@@ -66,7 +68,7 @@ ncqStorageRun3 ncq@NCQStorage3{..} = flip runContT pure do
     let q = ncqWriteOps ! i
     forever (liftIO $ join $ atomically (readTQueue q))
 
-  replicateM_ 2 $ spawnActivity $ fix \next -> do
+  replicateM_ 2 $ spawnActivity $ forever $ flip runContT pure $ callCC \exit -> do
 
       (h, answ) <- atomically $ readTQueue ncqReadReq
       let answer l = atomically (putTMVar answ l)
@@ -75,26 +77,62 @@ ncqStorageRun3 ncq@NCQStorage3{..} = flip runContT pure do
 
       atomically (ncqLookupEntrySTM ncq h) >>= \case
         Nothing  -> none
-        Just e -> answer (Just (InMemory (ncqEntryData e))) >> next
+        Just e -> answer (Just (InMemory (ncqEntryData e))) >> exit ()
+
+      ContT $ ncqWithState ncq
 
       NCQState{..} <- readTVarIO ncqState
 
       for_ ncqStateIndex $ \(_, fk) -> do
-       CachedIndex bs nw <- ncqGetCachedIndex ncq fk
-       ncqLookupIndex h (bs, nw) >>= \case
-        Just (IndexEntry fk o s) -> answer (Just (InFossil fk o s)) >> next
+       CachedIndex bs nw <- lift $ ncqGetCachedIndex ncq fk
+       lift (ncqLookupIndex h (bs, nw)) >>= \case
+        Just (IndexEntry fk o s) -> answer (Just (InFossil fk o s)) >> exit ()
         Nothing -> none
 
       -- debug $ "NOT FOUND SHIT" <+> pretty h
-      answer Nothing >> next
+      answer Nothing >> exit ()
 
   spawnActivity measureWPS
 
-  spawnActivity $ forever do
-    withSem ncqServiceSem (ncqSweepObsoleteStates ncq)
-    pause @'Seconds 10
+  spawnActivity $ postponed 10 $ forever do
 
-  spawnActivity (ncqSweepLoop ncq)
+    ema <- readTVarIO ncqWriteEMA
+
+    when ( ema < ncqIdleThrsh ) do
+      ncqSweepObsoleteStates ncq
+
+    -- FIXME: timeout-hardcode
+    pause @'Seconds 60
+
+  spawnActivity $ forever do
+    pause @'Seconds 30
+    ema <- readTVarIO ncqWriteEMA
+    debug $ "EMA" <+> pretty (realToFrac @_ @(Fixed E3) ema)
+
+  spawnActivity $ postponed 10 $ forever do
+    ema <- readTVarIO ncqWriteEMA
+
+    when ( ema < ncqIdleThrsh ) do
+      ncqSweepFiles ncq
+
+    -- FIXME: timeout-hardcode
+    pause @'Seconds 60
+
+  spawnActivity $ postponed 10 $ forever $ void $ runMaybeT do
+    ema <- readTVarIO ncqWriteEMA
+
+    when (ema > ncqIdleThrsh) $ pause @'Seconds 10 >> mzero
+
+    compacted <- lift $ ncqIndexCompactStep ncq
+
+    when compacted mzero
+
+    k0 <- readTVarIO ncqStateKey
+    void $ lift $ race (pause @'Seconds 600) do
+      flip fix k0 $ \waitState k1 -> do
+        pause @'Seconds 60
+        k2 <- readTVarIO ncqStateKey
+        when (k2 == k1) $  waitState k2
 
   flip fix RunNew $ \loop -> \case
     RunFin -> do
@@ -216,6 +254,8 @@ ncqStorageRun3 ncq@NCQStorage3{..} = flip runContT pure do
         alpha = 0.1
         step  = 1.00
 
+    postponed n m = liftIO (pause @'Seconds n) >> m
+
 data RunSt =
     RunNew
   | RunWrite (FileKey, Fd, Int, Int)
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/State.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/State.hs
index 0b92adbb..fb663c6d 100644
--- a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/State.hs
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/State.hs
@@ -4,6 +4,7 @@ module HBS2.Storage.NCQ3.Internal.State where
 import HBS2.Storage.NCQ3.Internal.Prelude
 import HBS2.Storage.NCQ3.Internal.Types
 import HBS2.Storage.NCQ3.Internal.Files
+import HBS2.Storage.NCQ3.Internal.MMapCache
 
 import Data.Config.Suckless.Script
 
@@ -14,6 +15,7 @@ import Control.Monad.Reader
 import Control.Monad.Trans.Maybe
 import Control.Monad.Trans.Cont
 import Data.HashSet qualified as HS
+import Data.HashMap.Strict qualified as HM
 import Data.Set qualified as Set
 import Data.ByteString qualified as BS
 import UnliftIO.IO.File
@@ -38,6 +40,7 @@ ncqStateUpdate ncq@NCQStorage3{..} action = do
 
   s1 <- atomically do
           void $ runReaderT (fromStateOp action) ncq
+          modifyTVar ncqWrites succ
           readTVar ncqState
 
   unless (s1 == s0) do
@@ -45,7 +48,7 @@ ncqStateUpdate ncq@NCQStorage3{..} action = do
     let snkFile = ncqGetFileName ncq (StateFile key)
     liftIO $ withBinaryFileDurableAtomic snkFile WriteMode $ \fh -> do
       IO.hPrint fh (pretty s1)
-    atomically $ writeTVar ncqStateKey (Just key)
+    atomically $ writeTVar ncqStateKey key
 
 ncqStateAddDataFile :: FileKey -> StateOP ()
 ncqStateAddDataFile fk = do
@@ -53,6 +56,13 @@ ncqStateAddDataFile fk = do
   StateOP $ lift do
     modifyTVar ncqState (over #ncqStateFiles (HS.insert fk))
 
+ncqStateDelDataFile :: FileKey -> StateOP ()
+ncqStateDelDataFile fk = do
+  sto@NCQStorage3{..} <- ask
+  StateOP $ lift do
+    modifyTVar ncqState (over #ncqStateFiles (HS.delete fk))
+    ncqDelCachedDataSTM sto fk
+
 ncqStateAddFact :: Fact -> StateOP ()
 ncqStateAddFact fact = do
   NCQStorage3{..} <- ask
@@ -75,8 +85,11 @@ ncqStateAddIndexFile ts fk  = do
 
 ncqStateDelIndexFile :: FileKey  -> StateOP ()
 ncqStateDelIndexFile fk  = do
-  NCQStorage3{..} <- ask
-  StateOP $ lift $ modifyTVar' ncqState (over #ncqStateIndex $ filter f)
+  sto@NCQStorage3{..} <- ask
+  StateOP $ lift do
+    modifyTVar' ncqState (over #ncqStateIndex $ filter f)
+    ncqDelCachedIndexSTM sto fk
+
   where f (_,b) = b /= fk
 
 sortIndexes :: NCQState -> NCQState
@@ -94,6 +107,41 @@ ncqFileFastCheck fp = do
   unless ( BS.length mmaped == fromIntegral s ) do
     throwIO $ NCQFsckIssueExt (FsckInvalidFileSize (fromIntegral s))
 
+ncqStateCapture :: forall m . MonadUnliftIO m
+            => NCQStorage3
+            -> m FileKey
+
+ncqStateCapture me@NCQStorage3{..} = do
+  atomically do
+    key      <- readTVar ncqStateKey
+    stateUse <- readTVar ncqStateUse
+    case HM.lookup key stateUse of
+      Just (_, tv) -> modifyTVar tv succ
+      Nothing      -> do
+        state    <- readTVar ncqState
+        new   <- (state,) <$> newTVar 1
+        modifyTVar ncqStateUse (HM.insert key new)
+    pure key
+
+ncqStateDismiss :: forall m . MonadUnliftIO m
+                => NCQStorage3
+                -> FileKey
+                -> m ()
+ncqStateDismiss me@NCQStorage3{..} key = atomically do
+  useMap <- readTVar ncqStateUse
+  case HM.lookup key useMap of
+    Nothing -> pure ()
+    Just (_, tv) -> do
+      modifyTVar tv (max 0 . pred)
+      cnt <- readTVar tv
+      when (cnt <= 0) do
+        modifyTVar ncqStateUse (HM.delete key)
+
+ncqWithState :: forall a m . MonadUnliftIO m
+             => NCQStorage3
+             -> ( FileKey -> m a  )
+             -> m a
+ncqWithState sto = bracket (ncqStateCapture sto) (ncqStateDismiss sto)
 
 readStateMay :: forall m . MonadUnliftIO m
              => NCQStorage3
@@ -117,9 +165,6 @@ readStateMay sto key = fmap sortIndexes <$> do
        ListVal [SymbolVal "f",  LitIntVal n] ->
          ncqState0 { ncqStateFiles = HS.singleton (fromIntegral n) }
 
-       ListVal [SymbolVal "fi", LitIntVal a, LitIntVal b] ->
-         ncqState0 { ncqStateFacts = Set.singleton (FI (DataFile (fromIntegral a)) (IndexFile (fromIntegral b))) }
-
        ListVal [SymbolVal "fp", LitIntVal a, LitIntVal s] ->
          ncqState0 { ncqStateFacts = Set.singleton (P (PData (DataFile $ fromIntegral a) (fromIntegral s))) }
 
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Sweep.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Sweep.hs
index a733a782..3c88a72b 100644
--- a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Sweep.hs
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Sweep.hs
@@ -13,38 +13,46 @@ import Data.List qualified as List
 import Data.HashSet qualified as HS
 import System.Posix.Files qualified as PFS
 import Control.Monad.Trans.Maybe
+import Data.HashMap.Strict qualified as HM
 
-data SweepSt = SweepWaitIdle
-             | SweepCheckEMA SweepSt
-             | SweepSomething
+ncqLiveKeys :: forall m . MonadUnliftIO m => NCQStorage3 -> m (HashSet FileKey)
+ncqLiveKeys NCQStorage3{..} = do
+
+  merged <- atomically do
+    s0     <- readTVar ncqState
+    readTVar ncqStateUse <&> (s0<>) . foldMap fst . HM.elems
+
+  pure $ HS.fromList $ universeBi @_ @FileKey merged
+
+ncqSweepFiles :: forall m . MonadUnliftIO m => NCQStorage3 -> m ()
+ncqSweepFiles me@NCQStorage3{..} = withSem ncqServiceSem do
+
+  debug "ncqSweepFiles"
+
+  live <- ncqLiveKeys me
 
 
-ncqSweepLoop :: MonadUnliftIO m => NCQStorage3 -> m ()
-ncqSweepLoop me@NCQStorage3{..} = flip fix SweepWaitIdle $ \next -> \case
+  debug $ "ALIVE" <+> pretty (HS.toList live)
 
-  SweepWaitIdle -> do
-    debug "SweepWaitIdle"
-    pause @'Seconds 10
-    next (SweepCheckEMA SweepSomething)
+  fossils <- ncqListFilesBy me (List.isPrefixOf "f-")
+  indexes <- ncqListFilesBy me (List.isPrefixOf "i-")
 
-  SweepCheckEMA who -> do
-    ema <- readTVarIO ncqWriteEMA
-    debug $ "SweepCheckEMA" <+> pretty ema
-    if ema < ncqIdleThrsh then do
-      next who
-    else
-      next SweepWaitIdle
+  for_ indexes $ \(_, k) -> unless (HS.member k live) do
+    let fn = ncqGetFileName me (IndexFile k)
+    debug $ yellow "REMOVING" <+> pretty (takeFileName fn)
+    rm fn
+
+  for_ fossils $ \(_, k) -> unless (HS.member k live) do
+    let fn = ncqGetFileName me (DataFile k)
+    debug $ yellow "REMOVING" <+> pretty (takeFileName fn)
+    rm fn
 
-  SweepSomething -> do
-    debug $ "SweepSomething"
-    pause @'Seconds 10
-    next SweepWaitIdle
 
 ncqSweepObsoleteStates :: forall m .  MonadUnliftIO m => NCQStorage3 -> m ()
-ncqSweepObsoleteStates me@NCQStorage3{..} = void $ runMaybeT do
+ncqSweepObsoleteStates me@NCQStorage3{..} = withSem ncqServiceSem do
     debug $ "ncqSweepObsoleteStates"
 
-    k <- readTVarIO ncqStateKey >>= toMPlus
+    k <- readTVarIO ncqStateKey
 
     r <- liftIO $ try @_ @SomeException do
           ts <- PFS.getFileStatus (ncqGetFileName me (StateFile k)) <&> PFS.modificationTimeHiRes
@@ -55,10 +63,9 @@ ncqSweepObsoleteStates me@NCQStorage3{..} = void $ runMaybeT do
             when (f /= k && t < ts) do
               debug $ yellow "TO REMOVE" <+> pretty (toFileName (StateFile f))
               rm (ncqGetFileName me (StateFile f))
-    lift do
 
-      case r of
-        Left e  -> err ("SweepStates failed" <+> viaShow e)
-        Right{} -> none
+    case r of
+      Left e  -> err ("SweepStates failed" <+> viaShow e)
+      Right{} -> none
 
 
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Types.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Types.hs
index f4b96bba..882d7f27 100644
--- a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Types.hs
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Types.hs
@@ -49,9 +49,7 @@ data Location =
      | InMemory {-# UNPACK #-} !ByteString
 
 
-data Fact =
-    FI (DataFile FileKey) (IndexFile FileKey) -- file X has index Y
-  | P  PData                                  -- pending, not indexed
+data Fact = P PData  -- pending, not indexed
   deriving stock (Eq,Ord,Data)
 
 data PData = PData (DataFile FileKey) Word64
@@ -92,7 +90,8 @@ data NCQStorage3 =
   , ncqMMapCachedData :: TVar (HashPSQ FileKey CachePrio CachedData)
   , ncqMemTable       :: Vector Shard
   , ncqState          :: TVar NCQState
-  , ncqStateKey       :: TVar (Maybe FileKey)
+  , ncqStateKey       :: TVar FileKey
+  , ncqStateUse       :: TVar (HashMap FileKey (NCQState, TVar Int))
   , ncqWrites         :: TVar Int
   , ncqWriteEMA       :: TVar Double  -- for writes-per-seconds
   , ncqWriteQ         :: TVar (Seq HashRef)
@@ -188,6 +187,5 @@ instance Pretty NCQState where
         | f <- Set.toList ncqStateFacts
         ]
 
-      pf (FI (DataFile a) (IndexFile b)) = "fi" <+> pretty a <+> pretty b
       pf (P (PData (DataFile a) s)) = "fp" <+> pretty a <+> pretty s
 
diff --git a/hbs2-tests/test/NCQ3.hs b/hbs2-tests/test/NCQ3.hs
index 00c64a52..8b1492d3 100644
--- a/hbs2-tests/test/NCQ3.hs
+++ b/hbs2-tests/test/NCQ3.hs
@@ -31,6 +31,7 @@ import Data.Config.Suckless.System
 import NCQTestCommon
 
 import Data.HashSet qualified as HS
+import Data.HashMap.Strict qualified as HM
 import Test.Tasty.HUnit
 import Data.ByteString qualified as BS
 import Data.Ord
@@ -38,6 +39,7 @@ import Data.Set qualified as Set
 import System.Random.MWC as MWC
 import Control.Concurrent.STM qualified as STM
 import Data.List qualified as List
+import Control.Monad.Trans.Cont
 import UnliftIO
 
 {-HLINT ignore "Functor law"-}
@@ -186,19 +188,59 @@ ncq3Tests = do
 
   entry $ bindMatch "test:ncq3:sweep" $ nil_ \e -> do
 
+      t0 <- getTimeCoarse
+
       let (opts,args) = splitOpts [] e
       let num = headDef 1000 [ fromIntegral n | LitIntVal n <- args ]
       g <- liftIO MWC.createSystemRandom
 
       runTest $ \TestEnv{..} -> do
-        ncqWithStorage3 testEnvDir $ \sto@NCQStorage3{..} -> do
-           notice $ "write" <+> pretty num
+        ncqWithStorage3 testEnvDir $ \sto@NCQStorage3{..} -> flip runContT pure do
+
            hst <- newTVarIO ( mempty :: HashSet HashRef )
+           lostt <- newTVarIO 0
+           req   <- newTVarIO 0
+
+           ContT $ withAsync $ forever do
+            pause @'Seconds 20
+            t <- getTimeCoarse <&> sec2 . (*1e-9) . realToFrac . toNanoSecs . (+ (-t0))
+            l <- readTVarIO lostt
+            r <- readTVarIO req
+            pp <- readTVarIO ncqStateUse <&> HM.size
+            let c = if l > 0 then red else id
+            debug $ "Elapsed" <+> pretty t <+> pretty pp <+> pretty r <+> c (pretty l)
+
+           ContT $ withAsync $ forever do
+            p <- liftIO $ uniformRM (0, 0.75) g
+            pause @'Seconds (realToFrac p)
+            hh <- readTVarIO hst
+
+            when (HS.size hh > 0) do
+
+              i <- liftIO $ uniformRM (0, HS.size hh - 1) g
+              let hi = HS.toList hh !! i
+              found <- ncqLocate sto hi <&> isJust
+              atomically $ modifyTVar req succ
+
+              unless found do
+                err $ red "NOT FOUND" <+> pretty hi
+                atomically $ modifyTVar lostt succ
+
+           notice $ "write" <+> pretty num
            replicateM_ num do
              n <- liftIO $ uniformRM (1024, 64*1024) g
              bs <- liftIO $ genRandomBS g n
-             h <- ncqPutBS sto (Just B) Nothing bs
+             h <- lift  $ ncqPutBS sto (Just B) Nothing bs
              atomically $ modifyTVar hst (HS.insert h)
 
-           pause @'Seconds 300
+           pause @'Seconds 180
+
+           notice "check after compaction"
+
+           h1 <- readTVarIO hst
+
+           for_ h1 $ \h -> lift do
+              found <- ncqLocate sto h <&> isJust
+              liftIO $ assertBool (show $ "found" <+> pretty h) found
+