diff --git a/cmd/cachefs/main.go b/cmd/cachefs/main.go
index 1f28261..5ae43ea 100644
--- a/cmd/cachefs/main.go
+++ b/cmd/cachefs/main.go
@@ -49,7 +49,7 @@ func main() {
 	flag.IntVar(&max, "max", -1, "max parallel preloads")
 	flag.IntVar(&bs, "bs", -1, "tune preload buffer size in bytes (default: 8192)")
 	flag.Int64Var(&quota, "quota", 1, "max disk usage quota for the dst cache in GiB")
-	flag.BoolVar(&block, "block", false, "block until sftp is connected")
+	flag.BoolVar(&block, "block", true, "block until sftp is connected")
 	flag.Parse()
 
 	log = klogr.New().WithName("main")
@@ -82,6 +82,7 @@ func main() {
 		),
 	}
 	go func() {
+		log.Info("starting main server", "addr", listenHttp)
 		err := s.ListenAndServe()
 		if err != nil && err != http.ErrServerClosed {
 			klog.Fatalf("init failed: %s", err)
@@ -92,6 +93,7 @@ func main() {
 		cache *http.Server
 	)
 	if listenWebdav != "" {
+		log.Info("starting webdav server", "addr", listenWebdav)
 		dav = &http.Server{
 			Addr: listenWebdav,
 			Handler: srv.NewWebDavServer(
@@ -107,6 +109,7 @@ func main() {
 		}()
 	}
 	if listenCache != "" {
+		log.Info("starting cache server", "addr", listenCache)
 		cache = &http.Server{
 			Addr: listenCache,
 			Handler: srv.NewCacheServer(
diff --git a/pkg/fs/metadata.go b/pkg/fs/metadata.go
index c621942..a4478dd 100644
--- a/pkg/fs/metadata.go
+++ b/pkg/fs/metadata.go
@@ -5,6 +5,7 @@ package fs
 import (
 	"cachefs/pkg/chunk"
 	"cachefs/pkg/provider"
+	"cachefs/pkg/provider/sftp"
 	"context"
 	"encoding/json"
 	"errors"
@@ -80,19 +81,20 @@ func MetadataGenerator(file string, dst provider.FS, fstat, encrypted bool) erro
 			return nil
 		}
 		size := fi.Size()
+		path = "/" + strings.TrimPrefix(path, dst.Root())
 		if fstat {
 			blocks, err := dst.Fstat(f.Fd())
 			if err != nil {
 				return nil
 			}
 			if size <= blocks*512 {
-				md[strings.TrimPrefix(path, dst.Root())] = &Metadata{
+				md[path] = &Metadata{
 					Size:   size,
 					Chunks: chunk.Chunks{{0, size}},
 				}
 			}
 		} else {
-			md[strings.TrimPrefix(path, dst.Root())] = &Metadata{
+			md[path] = &Metadata{
 				Size:   size,
 				Chunks: chunk.Chunks{{0, size}},
 			}
@@ -332,7 +334,7 @@ func MapError(err error) error {
 }
 
 func IsIOErr(err error) bool {
-	return MapError(err) == IOErr
+	return MapError(err) == IOErr || errors.Is(err, sftp.ErrNotConnected)
 }
 
 type Metadata struct {
diff --git a/pkg/fs/preload.go b/pkg/fs/preload.go
index 664f854..1f02dd9 100644
--- a/pkg/fs/preload.go
+++ b/pkg/fs/preload.go
@@ -53,8 +53,12 @@ func NewPreloadHandler(ctx context.Context, fs *FS, max int, log logr.Logger) (p
 func (ph *PreloadHandler) CancelPreload(name string) {
 	ph.mu.Lock()
 	defer ph.mu.Unlock()
-	if p, ok := ph.pm[name]; ok && p.Running {
-		p.cancel()
+	p, ok := ph.pm[name]
+	if ok {
+		if p.Running {
+			p.cancel()
+		}
+		delete(ph.pm, name)
 	}
 }
 
diff --git a/pkg/provider/crypto/file.go b/pkg/provider/crypto/file.go
index 027132f..1927465 100644
--- a/pkg/provider/crypto/file.go
+++ b/pkg/provider/crypto/file.go
@@ -5,12 +5,15 @@ import (
 	"io"
 	"io/fs"
 	"os"
+	"sync"
 )
 
 var _ provider.File = (*file)(nil)
 
 type file struct {
 	provider.File
+	rmu    sync.Mutex
+	wmu    sync.Mutex
 	fs     *FS
 	r      *reader
 	w      *writer
@@ -140,10 +143,12 @@ func (f *file) Seek(offset int64, whence int) (n int64, err error) {
 	f.r.nonce = f.nonce
 	f.w.nonce = f.nonce
 	f.r.off = roff
+	f.r.cn = cn
 	return
 }
 
 func (f *file) Read(p []byte) (n int, err error) {
+	f.r.cn = -1
 	n, err = f.r.Read(p)
 	return
 }
@@ -154,6 +159,8 @@ func (f *file) Write(p []byte) (n int, err error) {
 }
 
 func (f *file) ReadAt(p []byte, pos int64) (n int, err error) {
+	f.rmu.Lock()
+	defer f.rmu.Unlock()
 	cn, _, roff := align(pos)
 	var last bool
 	if f.r.cn != cn {
@@ -165,7 +172,6 @@ func (f *file) ReadAt(p []byte, pos int64) (n int, err error) {
 		if err != nil {
 			return
 		}
-		f.r.cn = cn
 	}
 	n = copy(p, f.r.unread[roff:])
 	if last && len(f.r.unread) == n+int(roff) {
@@ -175,6 +181,8 @@ func (f *file) ReadAt(p []byte, pos int64) (n int, err error) {
 }
 
 func (f *file) WriteAt(data []byte, pos int64) (n int, err error) {
+	f.wmu.Lock()
+	defer f.wmu.Unlock()
 	cn, off, woff := align(pos)
 	c, ok := f.w.cm[cn]
 	if !ok {