diff --git a/hbs2-storage-ncq/hbs2-storage-ncq.cabal b/hbs2-storage-ncq/hbs2-storage-ncq.cabal
index baa2a0f2..17fd29c7 100644
--- a/hbs2-storage-ncq/hbs2-storage-ncq.cabal
+++ b/hbs2-storage-ncq/hbs2-storage-ncq.cabal
@@ -54,11 +54,20 @@ common shared-properties
                      , TypeApplications
                      , TypeFamilies
                      , TypeOperators
+                     , RecordWildCards
 
 
 library
     import:           shared-properties
     exposed-modules:
+      HBS2.Storage.NCQ3
+      HBS2.Storage.NCQ3.Internal
+      HBS2.Storage.NCQ3.Internal.Types
+      HBS2.Storage.NCQ3.Internal.Prelude
+      HBS2.Storage.NCQ3.Internal.State
+      HBS2.Storage.NCQ3.Internal.Run
+      HBS2.Storage.NCQ3.Internal.Memtable
+      HBS2.Storage.NCQ3.Internal.Index
       HBS2.Storage.NCQ
       HBS2.Storage.NCQ2
       HBS2.Storage.NCQ2.Internal
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ/Types.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ/Types.hs
index 5bc933d4..6f007aba 100644
--- a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ/Types.hs
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ/Types.hs
@@ -212,3 +212,10 @@ posixToTimeSpec pt =
   in TimeSpec (fromIntegral s) ns
 
 
+megabytes :: forall a . Integral a => a
+megabytes = 1024 ^ 2
+
+gigabytes :: forall a . Integral a => a
+gigabytes = 1024 ^ 3
+
+
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2.hs
index 57eefdb5..f43f5a33 100644
--- a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2.hs
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2.hs
@@ -85,11 +85,12 @@ ncqStorageOpen2 fp upd = do
   let ncqFsync      = 16   * megabytes
   let ncqWriteQLen  = 1024 * 4
   let ncqMinLog     = 512 * megabytes
-  let ncqMaxLog     = 16 * gigabytes -- ???
+  -- let ncqMaxLog     = 16 * gigabytes -- ???
+  let ncqMaxLog     = 2 * ncqMinLog --  * gigabytes -- ???
   let ncqWriteBlock = max 128 $ ncqWriteQLen `div` 2
   let ncqMaxCached  = 128
   let ncqIdleThrsh  = 50.00
-  let ncqPostponeMerge = 30.00
+  let ncqPostponeMerge = 300.00
   let ncqPostponeSweep = 2 * ncqPostponeMerge
   let ncqLuckyNum   = 2
 
@@ -493,7 +494,8 @@ ncqStorageRun2 ncq@NCQStorage2{..} = flip runContT pure do
   spawnActivity $ postponed 20 $ forever do
     ema <- readTVarIO ncqWriteEMA
     when (ema < 50 ) do
-      ncqKeyNumIntersectionProbe ncq
+      -- ncqKeyNumIntersectionProbe ncq
+      ncqTombCountProbe ncq
 
     pause @'Seconds 10
 
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2/Internal/Probes.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2/Internal/Probes.hs
index aaf24a15..6df1658d 100644
--- a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2/Internal/Probes.hs
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2/Internal/Probes.hs
@@ -23,29 +23,54 @@ import Lens.Micro.Platform
 import System.Random.MWC qualified as MWC
 import UnliftIO
 
-ncqKeyNumIntersectionProbe :: MonadUnliftIO m => NCQStorage2 -> m ()
-ncqKeyNumIntersectionProbe me@NCQStorage2{..} = useVersion me $ const $ void $ runMaybeT do
 
-  -- Фильтруем pending
-  files0 <- lift (ncqListTrackedFiles me)
+randomTrackedFile :: MonadUnliftIO m => NCQStorage2 -> m (Maybe FileKey)
+randomTrackedFile ncq@NCQStorage2{..} = runMaybeT do
+  files0 <- lift (ncqListTrackedFiles ncq)
   let files = V.toList $ V.filter (isNotPending . view _2) files0
+  guard (not (null files))
+  i <- liftIO $ MWC.uniformRM (0, length files - 1) ncqRndGen
+  pure (view _1 (files !! i))
 
-  when (length files < 2) mzero
+randomTrackedFilePair :: MonadUnliftIO m => NCQStorage2 -> m (Maybe (FileKey, FileKey))
+randomTrackedFilePair ncq@NCQStorage2{..} = runMaybeT do
+  files0 <- lift (ncqListTrackedFiles ncq)
+  let files = V.toList $ V.filter (isNotPending . view _2) files0
+  guard (length files >= 2)
 
-  (a,b) <- liftIO $ fix \next -> do
+  (a, b) <- liftIO $ fix \loop -> do
     i <- MWC.uniformRM (0, length files - 1) ncqRndGen
     j <- MWC.uniformRM (0, length files - 1) ncqRndGen
-    if i == j then next else pure (files !! min i j, files !! max i j)
+    if i == j then loop else pure (min i j, max i j)
 
-  let fka = view _1 a
-  let fkb = view _1 b
+  let fa = view _1 (files !! a)
+  let fb = view _1 (files !! b)
+  pure (fa, fb)
+
+
+ncqTombCountProbeFor :: MonadUnliftIO m => NCQStorage2 -> FileKey -> m (Maybe Int)
+ncqTombCountProbeFor ncq@NCQStorage2{..} fkey = runMaybeT do
+  let fIndex = ncqGetFileName ncq $ toFileName (IndexFile fkey)
+
+  (bs, nh) <- liftIO (nwayHashMMapReadOnly fIndex) >>= toMPlus
+
+  liftIO do
+    ref <- newTVarIO 0
+    nwayHashScanAll nh bs $ \_ k v -> do
+      let NCQIdxEntry _ s = decodeEntry v
+      when (k /= ncqEmptyKey && s < 64) $
+        atomically $ modifyTVar' ref (+1)
+    readTVarIO ref
+
+ncqKeyNumIntersectionProbeFor :: MonadUnliftIO m => NCQStorage2 -> (FileKey, FileKey) -> m (Maybe Int)
+ncqKeyNumIntersectionProbeFor ncq@NCQStorage2{..} (fka, fkb) = runMaybeT do
   let key = FactKey $ coerce $ hashObject @HbSync $ serialise $ List.sort [fka, fkb]
 
   known <- lift (readTVarIO ncqFacts <&> HM.member key)
-  when known mzero
+  guard (not known)
 
-  let fIndexA = ncqGetFileName me (toFileName (IndexFile fka))
-  let fIndexB = ncqGetFileName me (toFileName (IndexFile fkb))
+  let fIndexA = ncqGetFileName ncq (toFileName (IndexFile fka))
+  let fIndexB = ncqGetFileName ncq (toFileName (IndexFile fkb))
 
   idxPair' <- liftIO $ try @_ @IOException do
     (,) <$> nwayHashMMapReadOnly fIndexA
@@ -55,15 +80,23 @@ ncqKeyNumIntersectionProbe me@NCQStorage2{..} = useVersion me $ const $ void $ r
     Right (Just x, Just y) -> pure (x,y)
     _ -> warn ("can't load index pair" <+> pretty (fka, fkb)) >> mzero
 
-  n <- liftIO $ do
+  liftIO do
     ref <- newTVarIO 0
-    nwayHashScanAll n1 bs1 $ \_ k _ -> when (k /= ncqEmptyKey ) do
-        here <- ncqLookupIndex (coerce k) (bs2,n2)
-        when (isJust here) $ atomically $ modifyTVar' ref (+1)
-
+    nwayHashScanAll n1 bs1 $ \_ k _ -> when (k /= ncqEmptyKey) do
+      here <- ncqLookupIndex (coerce k) (bs2,n2)
+      when (isJust here) $ atomically $ modifyTVar' ref (+1)
     readTVarIO ref
 
-  debug $ yellow "ncqKeyNumIntersectionProbe"
-       <+> pretty fka <+> pretty fkb <+> pretty n
 
+ncqTombCountProbe :: MonadUnliftIO m => NCQStorage2 -> m ()
+ncqTombCountProbe ncq = useVersion ncq $ const $ void $ runMaybeT do
+  fk <- MaybeT (randomTrackedFile ncq)
+  count <- MaybeT (ncqTombCountProbeFor ncq fk)
+  debug $ yellow "ncqTombCountProbe" <+> pretty fk <+> pretty count
+
+ncqKeyNumIntersectionProbe :: MonadUnliftIO m => NCQStorage2 -> m ()
+ncqKeyNumIntersectionProbe ncq = useVersion ncq $ const $ void $ runMaybeT do
+  (fa, fb) <- MaybeT (randomTrackedFilePair ncq)
+  n <- MaybeT (ncqKeyNumIntersectionProbeFor ncq (fa, fb))
+  debug $ yellow "ncqKeyNumIntersectionProbe" <+> pretty fa <+> pretty fb <+> pretty n
 
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2/Internal/Types.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2/Internal/Types.hs
index f7ced96d..4f45cff1 100644
--- a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2/Internal/Types.hs
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ2/Internal/Types.hs
@@ -148,12 +148,6 @@ data NCQStorage2 =
   , ncqRndGen         :: Gen RealWorld
   }
 
-megabytes :: forall a . Integral a => a
-megabytes = 1024 ^ 2
-
-gigabytes :: forall a . Integral a => a
-gigabytes = 1024 ^ 3
-
 
 ncqGetFileName :: NCQStorage2 -> FilePath -> FilePath
 ncqGetFileName ncq fp = ncqGetWorkDir ncq </> takeFileName fp
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3.hs
new file mode 100644
index 00000000..0228d427
--- /dev/null
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3.hs
@@ -0,0 +1,8 @@
+module HBS2.Storage.NCQ3
+  ( module Exported )
+  where
+
+import HBS2.Storage.NCQ3.Internal.Types as Exported
+
+
+
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal.hs
new file mode 100644
index 00000000..942c411d
--- /dev/null
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal.hs
@@ -0,0 +1,136 @@
+{-# Language RecordWildCards #-}
+module HBS2.Storage.NCQ3.Internal where
+
+import HBS2.Storage.NCQ3.Internal.Prelude
+import HBS2.Storage.NCQ3.Internal.Types
+import HBS2.Storage.NCQ3.Internal.State
+import HBS2.Storage.NCQ3.Internal.Run
+
+import Control.Monad.Trans.Cont
+import Network.ByteOrder qualified as N
+import Data.HashPSQ qualified as PSQ
+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 System.FilePath.Posix
+import System.Posix.Files qualified as Posix
+import System.Posix.IO as PosixBase
+import System.Posix.Types as Posix
+import System.Posix.Unistd
+import System.Posix.IO.ByteString as Posix
+import System.Posix.Files ( getFileStatus
+                          , modificationTimeHiRes
+                          , setFileTimesHiRes
+                          , getFdStatus
+                          , FileStatus(..)
+                          , setFileMode
+                          )
+import System.Posix.Files qualified as PFS
+import System.IO.MMap as MMap
+
+ncqStorageOpen3 :: MonadIO m => FilePath -> (NCQStorage3 -> NCQStorage3) -> m NCQStorage3
+ncqStorageOpen3 fp upd = do
+  let ncqRoot           = fp
+  let ncqGen            = 0
+  let ncqFsync          = 16 * megabytes
+  let ncqWriteQLen      = 1024 * 4
+  let ncqMinLog         = 512 * megabytes
+  let ncqMaxLog         = 2 * ncqMinLog
+  let ncqWriteBlock     = max 128 $ ncqWriteQLen `div` 2
+  let ncqMaxCached      = 128
+  let ncqIdleThrsh      = 50.0
+  let ncqPostponeMerge  = 300.0
+  let ncqPostponeSweep  = 2 * ncqPostponeMerge
+  let ncqSalt           = "EstEFasxrCFqsGDxcY4haFcha9e4ZHRzsPbGUmDfdxLk"
+
+  cap <- getNumCapabilities
+
+  let shardNum = fromIntegral cap
+  let wopNum   = 2
+
+  ncqWriteQ       <- newTVarIO mempty
+  ncqMemTable     <- V.fromList <$> replicateM shardNum (newTVarIO mempty)
+  ncqMMapCache    <- newTVarIO PSQ.empty
+  ncqStateFiles   <- newTVarIO mempty
+  ncqStateIndex   <- newTVarIO mempty
+  ncqStateFileSeq <- newTVarIO 0
+  ncqStateVersion <- newTVarIO 0
+  ncqStateUsage   <- newTVarIO mempty
+  ncqWrites       <- newTVarIO 0
+  ncqWriteEMA     <- newTVarIO 0.0
+  ncqWriteOps     <- V.fromList <$> replicateM wopNum newTQueueIO
+  ncqAlive        <- newTVarIO False
+  ncqStopReq      <- newTVarIO False
+  ncqSyncReq      <- newTVarIO False
+  ncqOnRunWriteIdle <- newTVarIO none
+  ncqSyncNo       <- newTVarIO 0
+
+  let ncq = NCQStorage3{..} & upd
+
+  mkdir (ncqGetWorkDir ncq)
+  pure ncq
+
+ncqWithStorage3 :: MonadUnliftIO m => FilePath -> (NCQStorage3 -> m a) -> m a
+ncqWithStorage3 fp action = flip runContT pure do
+  sto <- lift (ncqStorageOpen3 fp id)
+  w <- ContT $ withAsync (ncqStorageRun3 sto) -- TODO: implement run
+  link w
+  r <- lift (action sto)
+  lift (ncqStorageStop3 sto)
+  wait w
+  pure r
+
+
+ncqShardIdx :: NCQStorage3 -> HashRef -> Int
+ncqShardIdx NCQStorage3{..} h =
+  fromIntegral (BS.head (coerce h)) `mod` V.length ncqMemTable
+{-# INLINE ncqShardIdx #-}
+
+ncqGetShard :: NCQStorage3 -> HashRef -> Shard
+ncqGetShard ncq@NCQStorage3{..} h = ncqMemTable ! ncqShardIdx ncq h
+{-# INLINE ncqGetShard #-}
+
+ncqStorageSync3 :: forall m . MonadUnliftIO m => NCQStorage3 -> m ()
+ncqStorageSync3 NCQStorage3{..} = atomically $ writeTVar ncqSyncReq True
+
+ncqOperation :: MonadIO m => NCQStorage3 -> m a -> m a -> m a
+ncqOperation ncq m0 m = do
+  alive <- readTVarIO (ncqAlive ncq)
+  if alive then m else m0
+
+
+ncqPutBS :: MonadUnliftIO m
+         => NCQStorage3
+         -> Maybe NCQSectionType
+         -> Maybe HashRef
+         -> ByteString
+         -> m HashRef
+ncqPutBS ncq@NCQStorage3{..} mtp mhref bs' = ncqOperation ncq (pure $ fromMaybe (HashRef (hashObject @HbSync bs')) mhref) do
+  waiter <- newEmptyTMVarIO
+
+  let work = do
+        let h = fromMaybe (HashRef (hashObject @HbSync bs')) mhref
+        let bs = ncqMakeSectionBS mtp h bs'
+        let shard = ncqGetShard ncq h
+        zero <- newTVarIO Nothing
+
+        atomically do
+          upd <- stateTVar shard $ flip HM.alterF h \case
+                   Nothing -> (True, Just (NCQEntry bs zero))
+                   Just e | ncqEntryData e /= bs  -> (True, Just (NCQEntry bs zero))
+                          | otherwise -> (False, Just e)
+
+          when upd  do
+            modifyTVar ncqWriteQ (|> h)
+
+          putTMVar waiter h
+
+  atomically do
+    nw <- readTVar ncqWrites <&> (`mod` V.length ncqWriteOps)
+    modifyTVar ncqWrites succ
+    writeTQueue (ncqWriteOps ! nw) work
+
+  atomically $ takeTMVar waiter
+
+
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Index.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Index.hs
new file mode 100644
index 00000000..91ef6226
--- /dev/null
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Index.hs
@@ -0,0 +1,69 @@
+module HBS2.Storage.NCQ3.Internal.Index where
+
+import HBS2.Storage.NCQ3.Internal.Prelude
+import HBS2.Storage.NCQ3.Internal.Types
+import HBS2.Storage.NCQ3.Internal.State
+
+import Streaming.Prelude qualified as S
+import Network.ByteOrder qualified as N
+import Control.Monad.Trans.Cont
+import Data.ByteString qualified as BS
+import System.IO.MMap
+
+ncqIndexFile :: MonadUnliftIO m => NCQStorage3 -> DataFile FileKey -> m FilePath
+ncqIndexFile n@NCQStorage3{}  fk = do
+
+  let fp   = toFileName fk & ncqGetFileName n
+  let dest = toFileName (IndexFile (coerce @_ @FileKey fk)) & ncqGetFileName n
+
+  debug $ "INDEX" <+> pretty fp <+> pretty dest
+
+  items <- S.toList_ do
+    ncqStorageScanDataFile n fp $ \o w k s -> case ncqIsMeta s of
+      Just M -> none
+      _ -> do
+        -- we need size in order to return block size faster
+        -- w/o search in fossil
+        let rs = (w + ncqSLen) & fromIntegral @_ @Word32 & N.bytestring32
+        let os = fromIntegral @_ @Word64 o & N.bytestring64
+        let record = os <> rs
+        S.yield (coerce k, record)
+
+  let (dir,name) = splitFileName fp
+  let idxTemp = (dropExtension name <> "-") `addExtension` ".cq$"
+
+  result <- nwayWriteBatch (nwayAllocDef 1.10 32 8 12) dir idxTemp items
+
+  mv result dest
+
+  -- ncqStateUpdate n [F 0 (coerce fk)]
+
+  pure dest
+
+
+ncqStorageScanDataFile :: MonadIO m
+                       => NCQStorage3
+                       -> FilePath
+                       -> ( Integer -> Integer -> HashRef -> ByteString -> m () )
+                       -> m ()
+ncqStorageScanDataFile ncq fp' action = do
+  let fp = ncqGetFileName ncq fp'
+  mmaped <- liftIO (mmapFileByteString fp Nothing)
+
+  flip runContT pure $ callCC \exit -> do
+    flip fix (0,mmaped) $ \next (o,bs) -> do
+
+     when (BS.length bs < ncqSLen) $ exit ()
+
+     let w = BS.take ncqSLen bs & N.word32 & fromIntegral
+
+     when (BS.length bs < ncqSLen + w) $ exit ()
+
+     let kv = BS.drop ncqSLen bs
+
+     let k = BS.take ncqKeyLen kv & coerce @_ @HashRef
+     let v = BS.take (ncqFullDataLen (NCQFullRecordLen w)) $ BS.drop ncqKeyLen kv
+
+     lift (action o (fromIntegral w) k v)
+
+     next (ncqSLen + o + fromIntegral w, BS.drop (w+ncqSLen) bs)
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Memtable.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Memtable.hs
new file mode 100644
index 00000000..45193b6e
--- /dev/null
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Memtable.hs
@@ -0,0 +1,29 @@
+module HBS2.Storage.NCQ3.Internal.Memtable where
+
+import HBS2.Storage.NCQ3.Internal.Types
+import HBS2.Storage.NCQ3.Internal.Prelude
+
+import Data.ByteString qualified as BS
+import Data.HashMap.Strict qualified as HM
+import Data.Vector qualified as V
+
+ncqShardIdx :: NCQStorage3 -> HashRef -> Int
+ncqShardIdx NCQStorage3{..} h =
+  fromIntegral (BS.head (coerce h)) `mod` V.length ncqMemTable
+{-# INLINE ncqShardIdx #-}
+
+ncqGetShard :: NCQStorage3 -> HashRef -> Shard
+ncqGetShard ncq@NCQStorage3{..} h = ncqMemTable ! ncqShardIdx ncq h
+{-# INLINE ncqGetShard #-}
+
+
+ncqLookupEntrySTM :: NCQStorage3 -> HashRef -> STM (Maybe NCQEntry)
+ncqLookupEntrySTM ncq h = readTVar (ncqGetShard ncq h) <&> HM.lookup h
+
+ncqAlterEntrySTM :: NCQStorage3
+                 -> HashRef
+                 -> (Maybe NCQEntry -> Maybe NCQEntry)
+                 -> STM ()
+ncqAlterEntrySTM ncq h alterFn = do
+  let shard = ncqGetShard ncq h
+  modifyTVar shard (HM.alter alterFn h)
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Prelude.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Prelude.hs
new file mode 100644
index 00000000..cdb05e70
--- /dev/null
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Prelude.hs
@@ -0,0 +1,53 @@
+module HBS2.Storage.NCQ3.Internal.Prelude
+  ( module Exported
+  , NCQSectionType(..)
+  , megabytes
+  , gigabytes
+  , ncqMakeSectionBS
+  , ncqSLen
+  , ncqKeyLen
+  , ncqPrefixLen
+  , ncqRefPrefix
+  , ncqBlockPrefix
+  , ncqMetaPrefix
+  , ncqIsMeta
+  , ncqFullDataLen
+  , NCQFullRecordLen(..)
+  , ToFileName(..)
+  , IndexFile(..)
+  , DataFile(..)
+  , ByteString
+  , Vector, (!)
+  , Seq(..), (|>),(<|)
+  , HashSet
+  , HashMap
+  , HashPSQ
+  , IntMap
+  ) where
+
+import HBS2.Prelude as Exported
+
+import HBS2.Data.Log.Structured.NCQ as Exported
+import HBS2.Data.Types.Refs as Exported
+import HBS2.Hash as Exported
+import HBS2.Misc.PrettyStuff as Exported
+import HBS2.Storage.NCQ.Types
+import HBS2.System.Dir as Exported
+import HBS2.System.Logger.Simple.ANSI as Exported
+
+import Data.ByteString (ByteString)
+
+import Data.Maybe as Exported
+import Data.Coerce as Exported
+import Data.Word as Exported
+import Data.Vector (Vector,(!))
+import Data.Sequence (Seq(..),(|>),(<|))
+import Data.HashSet (HashSet)
+import Data.HashMap.Strict (HashMap)
+import Data.HashPSQ (HashPSQ)
+import Data.IntMap (IntMap)
+
+
+import UnliftIO as Exported
+import UnliftIO.Concurrent as Exported
+
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Run.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Run.hs
new file mode 100644
index 00000000..e1e542e9
--- /dev/null
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Run.hs
@@ -0,0 +1,228 @@
+{-# Language MultiWayIf #-}
+module HBS2.Storage.NCQ3.Internal.Run where
+
+import HBS2.Storage.NCQ.Types hiding (FileKey)
+import HBS2.Storage.NCQ3.Internal.Prelude
+import HBS2.Storage.NCQ3.Internal.Types
+import HBS2.Storage.NCQ3.Internal.State
+import HBS2.Storage.NCQ3.Internal.Memtable
+
+
+import Control.Monad.Trans.Cont
+import Network.ByteOrder qualified as N
+import Data.HashSet qualified as HS
+import Data.HashPSQ qualified as PSQ
+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 System.FilePath.Posix
+import System.Posix.Files qualified as Posix
+import System.Posix.IO as PosixBase
+import System.Posix.Types as Posix
+import System.Posix.Unistd
+import System.Posix.IO.ByteString as Posix
+import System.Posix.Files ( getFileStatus
+                          , modificationTimeHiRes
+                          , setFileTimesHiRes
+                          , getFdStatus
+                          , FileStatus(..)
+                          , setFileMode
+                          )
+import System.Posix.Files qualified as PFS
+import System.IO.MMap as MMap
+import Control.Concurrent.STM qualified as STM
+
+ncqStorageStop3 :: forall m . MonadUnliftIO m => NCQStorage3 -> m ()
+ncqStorageStop3 NCQStorage3{..} = atomically $ writeTVar ncqStopReq True
+
+ncqStorageRun3 :: forall m . MonadUnliftIO m
+               => NCQStorage3
+               -> m ()
+ncqStorageRun3 ncq@NCQStorage3{..} = flip runContT pure do
+  ContT $ bracket setAlive (const unsetAlive)
+
+  closeQ <- liftIO newTQueueIO
+
+  closer <- spawnActivity $ liftIO $ fix \loop -> do
+    what <- atomically do
+      tryReadTQueue closeQ >>= \case
+        Just e  -> pure $ Just e
+        Nothing -> do
+          stop  <- readTVar ncqStopReq
+          if not stop then STM.retry else pure Nothing
+
+    maybe1 what none $ \(fk :: FileKey, fh) -> do
+      debug $ red "CLOSE FILE" <+> pretty fk
+      closeFd fh
+      loop
+
+  let shLast = V.length ncqWriteOps - 1
+  spawnActivity $ pooledForConcurrentlyN_ (V.length ncqWriteOps) [0..shLast] $ \i -> do
+    let q = ncqWriteOps ! i
+    forever (liftIO $ join $ atomically (readTQueue q))
+
+  spawnActivity measureWPS
+
+  flip fix RunNew $ \loop -> \case
+    RunFin -> do
+      debug "exit storage"
+      atomically $ pollSTM closer >>= maybe STM.retry (const none)
+
+    RunNew -> do
+      alive <- readTVarIO ncqAlive
+      empty <- readTVarIO ncqWriteQ <&> Seq.null
+      if not alive && empty
+        then loop RunFin
+        else do
+          (fk, fhx) <- openNewDataFile
+          loop $ RunWrite (fk, fhx, 0, 0)
+
+
+    RunSync (fk, fh, w, total, continue) -> do
+
+      stop <- readTVarIO ncqStopReq
+      sync <- readTVarIO ncqSyncReq
+
+      let needClose = total >= ncqMinLog || stop
+
+      rest <- if not (sync || needClose || w > ncqFsync) then
+                  pure w
+                else do
+                  appendTailSection fh >> liftIO (fileSynchronise fh)
+                  atomically do
+                    writeTVar  ncqSyncReq False
+                    modifyTVar ncqSyncNo succ
+
+                  pure 0
+
+      if | needClose && continue -> do
+              atomically $ writeTQueue closeQ (fk, fh)
+              loop RunNew
+
+         | not continue -> loop RunFin
+
+         | otherwise -> loop $ RunWrite (fk, fh, rest, total)
+
+
+    RunWrite (fk, fh, w, total') -> do
+
+      let timeoutMicro = 10_000_000
+
+      chunk <- liftIO $ timeout timeoutMicro $ atomically do
+        stop  <- readTVar ncqStopReq
+        sy    <- readTVar ncqSyncReq
+        chunk <- stateTVar ncqWriteQ (Seq.splitAt ncqWriteBlock)
+
+        if | Seq.null chunk && stop             -> pure $ Left ()
+           | Seq.null chunk && not (stop || sy) -> STM.retry
+           | otherwise                          -> pure $ Right chunk
+
+      case chunk of
+        Nothing -> do
+          liftIO $ join $ readTVarIO ncqOnRunWriteIdle
+          if w == 0 then do
+            loop $ RunWrite (fk,fh,w,total')
+          else do
+            atomically $ writeTVar ncqSyncReq True
+            loop $ RunSync (fk, fh, w, total', True) -- exit ()
+
+        Just (Left{})  -> loop $ RunSync (fk, fh, w, total', False) -- exit ()
+
+        Just (Right chu) -> do
+          ws <- for chu $ \h -> do
+                  atomically (ncqLookupEntrySTM ncq h) >>= \case
+                    Just (NCQEntry bs w)  -> do
+                      atomically (writeTVar w (Just fk))
+                      lift (appendSection fh bs)
+
+                    _ -> pure 0
+
+          let written = sum ws
+          loop $ RunSync (fk, fh, w + written, total' + written, True)
+
+
+  pure ()
+
+  where
+    setAlive   = atomically $ writeTVar ncqAlive True
+    unsetAlive = atomically $ writeTVar ncqAlive False
+
+    openNewDataFile :: forall mx . MonadIO mx => mx (FileKey, Fd)
+    openNewDataFile = do
+      fname <- toFileName . DataFile <$> ncqGetNewFileKey ncq
+      touch fname
+      let flags = defaultFileFlags { exclusive = False, creat = Just 0o666 }
+      (fromString fname,) <$> liftIO (PosixBase.openFd fname  Posix.ReadWrite flags)
+
+    spawnActivity m = do
+      a <- ContT $ withAsync m
+      link a
+      pure a
+
+
+    measureWPS = void $ flip fix Nothing \loop -> \case
+      Nothing      -> do
+        w <- readTVarIO ncqWrites
+        t <- getTimeCoarse
+        pause @'Seconds step >> loop (Just (w,t))
+
+      Just (w0,t0) -> do
+        w1 <- readTVarIO ncqWrites
+        t1 <- getTimeCoarse
+        let dt = max 1e-9 (realToFrac @_ @Double (t1 - t0)) / 1e9
+            dw = fromIntegral (w1 - w0)
+        atomically $ modifyTVar ncqWriteEMA \ema -> alpha * (dw/dt) + 0.9 * ema
+        pause @'Seconds step >> loop (Just (w1,t1))
+
+      where
+        alpha = 0.1
+        step  = 1.00
+
+data RunSt =
+    RunNew
+  | RunWrite (FileKey, Fd, Int, Int)
+  | RunSync  (FileKey, Fd, Int, Int, Bool)
+  | RunFin
+
+
+zeroSyncEntry :: ByteString
+zeroSyncEntry = ncqMakeSectionBS (Just B) zeroHash zeroPayload
+  where zeroPayload = N.bytestring64 0
+        zeroHash    = HashRef (hashObject zeroPayload)
+{-# INLINE zeroSyncEntry #-}
+
+zeroSyncEntrySize :: Word64
+zeroSyncEntrySize = fromIntegral (BS.length zeroSyncEntry)
+{-# INLINE zeroSyncEntrySize #-}
+
+-- 1. It's M-record
+-- 2. It's last w64be == fileSize
+-- 3. It's hash == hash (bytestring64be fileSize)
+-- 4. recovery-strategy: start-to-end, end-to-start
+fileTailRecord :: Integral a => a -> ByteString
+fileTailRecord w = do
+  -- on open: last w64be == fileSize
+  let paylo = N.bytestring64 (fromIntegral w + zeroSyncEntrySize)
+  let h     = hashObject @HbSync paylo & coerce
+  ncqMakeSectionBS (Just M) h paylo
+{-# INLINE fileTailRecord #-}
+
+appendSection :: forall m . MonadUnliftIO m
+            => Fd
+            -> ByteString
+            -> m Int -- (FOff, Int)
+
+appendSection fh sect = do
+  -- off <- liftIO $ fdSeek fh SeekFromEnd 0
+  -- pure (fromIntegral off, fromIntegral len)
+  liftIO (Posix.fdWrite fh sect) <&> fromIntegral
+{-# INLINE appendSection #-}
+
+appendTailSection :: MonadIO m => Fd -> m ()
+appendTailSection fh = liftIO do
+  s <- Posix.fileSize <$> Posix.getFdStatus fh
+  void (appendSection fh (fileTailRecord s))
+{-# INLINE appendTailSection #-}
+
+
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/State.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/State.hs
new file mode 100644
index 00000000..c9cae517
--- /dev/null
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/State.hs
@@ -0,0 +1,26 @@
+module HBS2.Storage.NCQ3.Internal.State where
+
+import HBS2.Storage.NCQ3.Internal.Prelude
+import HBS2.Storage.NCQ3.Internal.Types
+
+import Data.ByteString.Char8 qualified as BS8
+import Text.Printf
+
+ncqGetFileName :: NCQStorage3 -> FilePath -> FilePath
+ncqGetFileName ncq fp = ncqGetWorkDir ncq </> takeFileName fp
+
+ncqGetWorkDir :: NCQStorage3 -> FilePath
+ncqGetWorkDir NCQStorage3{..} = ncqRoot </> show ncqGen
+
+ncqGetLockFileName :: NCQStorage3 -> FilePath
+ncqGetLockFileName ncq = ncqGetFileName ncq ".lock"
+
+ncqGetNewFileKey :: forall m . MonadIO m
+                    => NCQStorage3
+                    -> m FileKey
+ncqGetNewFileKey me@NCQStorage3{..} = fix \next -> do
+    n <- atomically $ stateTVar ncqStateFileSeq (\x -> (x, succ x))
+    let fname = ncqMakeFossilName n
+    here <- doesFileExist (ncqGetFileName me fname)
+    if here then next else pure n
+
diff --git a/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Types.hs b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Types.hs
new file mode 100644
index 00000000..f4774461
--- /dev/null
+++ b/hbs2-storage-ncq/lib/HBS2/Storage/NCQ3/Internal/Types.hs
@@ -0,0 +1,71 @@
+module HBS2.Storage.NCQ3.Internal.Types where
+
+import HBS2.Storage.NCQ3.Internal.Prelude
+
+import Text.Printf
+
+data CachedMMap =
+    CachedData  ByteString
+  | CachedIndex ByteString NWayHash
+
+
+type CachePrio = Word64
+
+type Shard = TVar (HashMap HashRef NCQEntry)
+
+type StateVersion = Word64
+
+newtype FileKey = FileKey Word32
+                  deriving newtype (Eq,Ord,Show,Num,Enum,Pretty,Hashable)
+
+instance IsString FileKey where
+  fromString = FileKey . read
+
+instance ToFileName (DataFile FileKey) where
+  toFileName (DataFile fk) = ncqMakeFossilName fk
+
+instance ToFileName (IndexFile FileKey) where
+  toFileName (IndexFile fk) = printf "i-%08x.cq" (coerce @_ @Word32 fk)
+
+data  NCQEntry =
+  NCQEntry
+  { ncqEntryData   :: !ByteString
+  , ncqDumped      :: !(TVar (Maybe FileKey))
+  }
+
+data NCQStorage3 =
+  NCQStorage3
+  { ncqRoot           :: FilePath
+  , ncqGen            :: Int
+  , ncqSalt           :: HashRef
+  , ncqPostponeMerge  :: Timeout 'Seconds
+  , ncqPostponeSweep  :: Timeout 'Seconds
+  , ncqFsync          :: Int
+  , ncqWriteQLen      :: Int
+  , ncqWriteBlock     :: Int
+  , ncqMinLog         :: Int
+  , ncqMaxLog         :: Int
+  , ncqMaxCached      :: Int
+  , ncqIdleThrsh      :: Double
+  , ncqMMapCache      :: TVar (HashPSQ FileKey CachePrio CachedMMap)
+  , ncqStateFiles     :: TVar (HashSet FileKey)
+  , ncqStateIndex     :: TVar (HashSet FileKey)
+  , ncqStateFileSeq   :: TVar FileKey
+  , ncqStateVersion   :: TVar StateVersion
+  , ncqStateUsage     :: TVar (IntMap (Int, HashSet FileKey))
+  , ncqMemTable       :: Vector Shard
+  , ncqWrites         :: TVar Int
+  , ncqWriteEMA       :: TVar Double  -- for writes-per-seconds
+  , ncqWriteQ         :: TVar (Seq HashRef)
+  , ncqWriteOps       :: Vector (TQueue (IO ()))
+  , ncqAlive          :: TVar Bool
+  , ncqStopReq        :: TVar Bool
+  , ncqSyncReq        :: TVar Bool
+  , ncqOnRunWriteIdle :: TVar (IO ())
+  , ncqSyncNo         :: TVar Int
+  }
+
+
+ncqMakeFossilName :: FileKey -> FilePath
+ncqMakeFossilName = printf "f-%08x.data" . coerce @_ @Word32
+
diff --git a/hbs2-tests/hbs2-tests.cabal b/hbs2-tests/hbs2-tests.cabal
index 906f73ed..6faa6860 100644
--- a/hbs2-tests/hbs2-tests.cabal
+++ b/hbs2-tests/hbs2-tests.cabal
@@ -1223,5 +1223,3 @@ executable test-ncq
         , unix
         , mwc-random
 
-
-
diff --git a/hbs2-tests/test/TestNCQ.hs b/hbs2-tests/test/TestNCQ.hs
index a116f46f..735539dc 100644
--- a/hbs2-tests/test/TestNCQ.hs
+++ b/hbs2-tests/test/TestNCQ.hs
@@ -1788,7 +1788,7 @@ main = do
             g <- liftIO MWC.createSystemRandom
             let dir = testEnvDir
             let n = 100000
-            let p = 0.45
+            let p = 0.25
 
             sizes <- replicateM n (uniformRM (4096, 256*1024) g)
 
@@ -1798,7 +1798,7 @@ main = do
               notice $ "write" <+> pretty (List.length sizes) <+> pretty "random blocks"
 
               ContT $ withAsync $ forever do
-                pause @'Seconds 0.10
+                pause @'Seconds 0.01
                 p1 <-  uniformRM (0,1) g
                 when (p1 <= p) do
                   hss <- readTVarIO hashes