diff --git a/objstorage/objstorageprovider/provider_test.go b/objstorage/objstorageprovider/provider_test.go
index ce58be2881..f11279648c 100644
--- a/objstorage/objstorageprovider/provider_test.go
+++ b/objstorage/objstorageprovider/provider_test.go
@@ -98,13 +98,14 @@ func TestProvider(t *testing.T) {
 				opts := objstorage.CreateOptions{
 					SharedCleanupMethod: objstorage.SharedRefTracking,
 				}
-				if len(d.CmdArgs) == 3 && d.CmdArgs[2].Key == "no-ref-tracking" {
-					d.CmdArgs = d.CmdArgs[:2]
+				if len(d.CmdArgs) == 5 && d.CmdArgs[4].Key == "no-ref-tracking" {
+					d.CmdArgs = d.CmdArgs[:4]
 					opts.SharedCleanupMethod = objstorage.SharedNoCleanup
 				}
 				var fileNum base.FileNum
 				var typ string
-				scanArgs("<file-num> <local|shared> [no-ref-tracking]", &fileNum, &typ)
+				var salt, size int
+				scanArgs("<file-num> <local|shared> <salt> <size> [no-ref-tracking]", &fileNum, &typ, &salt, &size)
 				switch typ {
 				case "local":
 				case "shared":
@@ -116,7 +117,10 @@ func TestProvider(t *testing.T) {
 				if err != nil {
 					return err.Error()
 				}
-				require.NoError(t, w.Write([]byte(d.Input)))
+				data := make([]byte, size)
+				// TODO(radu): write in chunks?
+				genData(byte(salt), 0, data)
+				require.NoError(t, w.Write(data))
 				require.NoError(t, w.Finish())
 
 				return log.String()
@@ -125,13 +129,14 @@ func TestProvider(t *testing.T) {
 				opts := objstorage.CreateOptions{
 					SharedCleanupMethod: objstorage.SharedRefTracking,
 				}
-				if len(d.CmdArgs) == 3 && d.CmdArgs[2].Key == "no-ref-tracking" {
-					d.CmdArgs = d.CmdArgs[:2]
+				if len(d.CmdArgs) == 5 && d.CmdArgs[4].Key == "no-ref-tracking" {
+					d.CmdArgs = d.CmdArgs[:4]
 					opts.SharedCleanupMethod = objstorage.SharedNoCleanup
 				}
 				var fileNum base.FileNum
 				var typ string
-				scanArgs("<file-num> <local|shared> [no-ref-tracking]", &fileNum, &typ)
+				var salt, size int
+				scanArgs("<file-num> <local|shared> <salt> <size> [no-ref-tracking]", &fileNum, &typ, &salt, &size)
 				switch typ {
 				case "local":
 				case "shared":
@@ -144,8 +149,10 @@ func TestProvider(t *testing.T) {
 				tmpFilename := fmt.Sprintf("temp-file-%d", tmpFileCounter)
 				f, err := fs.Create(tmpFilename)
 				require.NoError(t, err)
-				n, err := f.Write([]byte(d.Input))
-				require.Equal(t, len(d.Input), n)
+				data := make([]byte, size)
+				genData(byte(salt), 0, data)
+				n, err := f.Write(data)
+				require.Equal(t, len(data), n)
 				require.NoError(t, err)
 				require.NoError(t, f.Close())
 
@@ -162,10 +169,23 @@ func TestProvider(t *testing.T) {
 				if err != nil {
 					return err.Error()
 				}
-				data := make([]byte, int(r.Size()))
-				err = r.ReadAt(ctx, data, 0)
-				require.NoError(t, err)
-				return log.String() + fmt.Sprintf("data: %s\n", string(data))
+				rh := r.NewReadHandle(ctx)
+				log.Infof("size: %d", r.Size())
+				for _, l := range strings.Split(d.Input, "\n") {
+					var offset, size int
+					fmt.Sscanf(l, "%d %d", &offset, &size)
+					data := make([]byte, size)
+					err := rh.ReadAt(ctx, data, int64(offset))
+					if err != nil {
+						log.Infof("%d %d: %v", offset, size, err)
+					} else {
+						salt := checkData(d, t, offset, data)
+						log.Infof("%d %d: ok (salt %d)", offset, size, salt)
+					}
+				}
+				require.NoError(t, rh.Close())
+				require.NoError(t, r.Close())
+				return log.String()
 
 			case "remove":
 				var fileNum base.FileNum
@@ -289,3 +309,30 @@ func TestNotExistError(t *testing.T) {
 		})
 	}
 }
+
+// genData generates object data that can be checked later with checkData.
+func genData(salt byte, offset int, p []byte) {
+	for i := range p {
+		p[i] = salt ^ xor(offset+i)
+	}
+}
+
+func checkData(d *datadriven.TestData, t *testing.T, offset int, p []byte) (salt byte) {
+	t.Helper()
+	salt = p[0] ^ xor(offset)
+	for i := range p {
+		if p[i]^xor(offset+i) != salt {
+			d.Fatalf(t, "invalid data")
+		}
+	}
+	return salt
+}
+
+// xor returns the XOR of all bytes representing the integer.
+func xor(n int) byte {
+	v := uint64(n)
+	v ^= v >> 32
+	v ^= v >> 16
+	v ^= v >> 8
+	return byte(v)
+}
diff --git a/objstorage/objstorageprovider/testdata/provider/local b/objstorage/objstorageprovider/testdata/provider/local
index c8cd4171c0..a2f4ce375b 100644
--- a/objstorage/objstorageprovider/testdata/provider/local
+++ b/objstorage/objstorageprovider/testdata/provider/local
@@ -5,7 +5,7 @@ open p0 0
 <local fs> mkdir-all: p0 0755
 <local fs> open-dir: p0
 
-create 1 local
+create 1 local 1 1024
 foo
 ----
 <local fs> create: p0/000001.sst
@@ -13,21 +13,44 @@ foo
 <local fs> close: p0/000001.sst
 
 read 1
+0 512
+0 1024
+512 1024
 ----
-data: foo
+<local fs> open: p0/000001.sst
+size: 1024
+<local fs> read-at(0, 512): p0/000001.sst
+0 512: ok (salt 1)
+<local fs> read-at(0, 1024): p0/000001.sst
+0 1024: ok (salt 1)
+<local fs> prefetch(512, 65536): p0/000001.sst
+<local fs> read-at(512, 1024): p0/000001.sst
+512 1024: EOF
+<local fs> close: p0/000001.sst
 
 # A provider without shared storage creates object with shared preference
 # locally.
-create 2 shared
-bar
+create 2 shared 2 1024
 ----
 <local fs> create: p0/000002.sst
 <local fs> sync-data: p0/000002.sst
 <local fs> close: p0/000002.sst
 
 read 2
+0 512
+0 1024
+512 1024
 ----
-data: bar
+<local fs> open: p0/000002.sst
+size: 1024
+<local fs> read-at(0, 512): p0/000002.sst
+0 512: ok (salt 2)
+<local fs> read-at(0, 1024): p0/000002.sst
+0 1024: ok (salt 2)
+<local fs> prefetch(512, 65536): p0/000002.sst
+<local fs> read-at(512, 1024): p0/000002.sst
+512 1024: EOF
+<local fs> close: p0/000002.sst
 
 remove 1
 ----
@@ -41,27 +64,35 @@ read 1
 ----
 file 000001 (type 2) unknown to the objstorage provider: file does not exist
 
-link-or-copy 3 local
-three
+link-or-copy 3 local 3 100
 ----
 <local fs> create: temp-file-1
 <local fs> close: temp-file-1
 <local fs> link: temp-file-1 -> p0/000003.sst
 
 read 3
+0 100
 ----
-data: three
+<local fs> open: p0/000003.sst
+size: 100
+<local fs> read-at(0, 100): p0/000003.sst
+0 100: ok (salt 3)
+<local fs> close: p0/000003.sst
 
-link-or-copy 4 shared
-four
+link-or-copy 4 shared 4 1234
 ----
 <local fs> create: temp-file-2
 <local fs> close: temp-file-2
 <local fs> link: temp-file-2 -> p0/000004.sst
 
 read 4
+0 1234
 ----
-data: four
+<local fs> open: p0/000004.sst
+size: 1234
+<local fs> read-at(0, 1234): p0/000004.sst
+0 1234: ok (salt 4)
+<local fs> close: p0/000004.sst
 
 close
 ----
diff --git a/objstorage/objstorageprovider/testdata/provider/local_readahead b/objstorage/objstorageprovider/testdata/provider/local_readahead
new file mode 100644
index 0000000000..0f9873f0ad
--- /dev/null
+++ b/objstorage/objstorageprovider/testdata/provider/local_readahead
@@ -0,0 +1,51 @@
+open p1 1
+----
+<local fs> mkdir-all: p1 0755
+<local fs> open-dir: p1
+<local fs> open-dir: p1
+<local fs> create: p1/SHARED-CATALOG-000001
+<local fs> sync: p1/SHARED-CATALOG-000001
+<local fs> create: p1/marker.shared-catalog.000001.SHARED-CATALOG-000001
+<local fs> close: p1/marker.shared-catalog.000001.SHARED-CATALOG-000001
+<local fs> sync: p1
+<local fs> sync: p1/SHARED-CATALOG-000001
+
+create 1 local 1 2000000
+----
+<local fs> create: p1/000001.sst
+<local fs> sync-data: p1/000001.sst
+<local fs> sync-data: p1/000001.sst
+<local fs> close: p1/000001.sst
+
+# We should see prefetch calls, and eventually a reopen
+# (with sequential reads option).
+read 1
+0 1000
+1000 15000
+16000 30000
+46000 10000
+56000 50000
+106000 30000
+140000 80000
+----
+<local fs> open: p1/000001.sst
+size: 2000000
+<local fs> read-at(0, 1000): p1/000001.sst
+0 1000: ok (salt 1)
+<local fs> read-at(1000, 15000): p1/000001.sst
+1000 15000: ok (salt 1)
+<local fs> prefetch(16000, 65536): p1/000001.sst
+<local fs> read-at(16000, 30000): p1/000001.sst
+16000 30000: ok (salt 1)
+<local fs> read-at(46000, 10000): p1/000001.sst
+46000 10000: ok (salt 1)
+<local fs> prefetch(56000, 131072): p1/000001.sst
+<local fs> read-at(56000, 50000): p1/000001.sst
+56000 50000: ok (salt 1)
+<local fs> read-at(106000, 30000): p1/000001.sst
+106000 30000: ok (salt 1)
+<local fs> open: p1/000001.sst
+<local fs> read-at(140000, 80000): p1/000001.sst
+140000 80000: ok (salt 1)
+<local fs> close: p1/000001.sst
+<local fs> close: p1/000001.sst
diff --git a/objstorage/objstorageprovider/testdata/provider/shared_attach b/objstorage/objstorageprovider/testdata/provider/shared_attach
index 77df361773..69cdbbcdbf 100644
--- a/objstorage/objstorageprovider/testdata/provider/shared_attach
+++ b/objstorage/objstorageprovider/testdata/provider/shared_attach
@@ -13,32 +13,28 @@ open p1 1
 <local fs> sync: p1
 <local fs> sync: p1/SHARED-CATALOG-000001
 
-create 1 shared
-obj-one
+create 1 shared 1 100
 ----
 <shared> create object "61a6-1-000001.sst"
-<shared> close writer for "61a6-1-000001.sst" after 7 bytes
+<shared> close writer for "61a6-1-000001.sst" after 100 bytes
 <shared> create object "61a6-1-000001.sst.ref.1.000001"
 <shared> close writer for "61a6-1-000001.sst.ref.1.000001" after 0 bytes
 
-create 2 shared
-obj-two
+create 2 shared 2 200
 ----
 <shared> create object "a629-1-000002.sst"
-<shared> close writer for "a629-1-000002.sst" after 7 bytes
+<shared> close writer for "a629-1-000002.sst" after 200 bytes
 <shared> create object "a629-1-000002.sst.ref.1.000002"
 <shared> close writer for "a629-1-000002.sst.ref.1.000002" after 0 bytes
 
-create 3 shared
-obj-three
+create 3 shared 3 300
 ----
 <shared> create object "eaac-1-000003.sst"
-<shared> close writer for "eaac-1-000003.sst" after 9 bytes
+<shared> close writer for "eaac-1-000003.sst" after 300 bytes
 <shared> create object "eaac-1-000003.sst.ref.1.000003"
 <shared> close writer for "eaac-1-000003.sst.ref.1.000003" after 0 bytes
 
-create 100 local
-obj-one
+create 100 local 100 15
 ----
 <local fs> create: p1/000100.sst
 <local fs> sync-data: p1/000100.sst
@@ -83,8 +79,7 @@ open p2 2
 <local fs> sync: p2
 <local fs> sync: p2/SHARED-CATALOG-000001
 
-create 100 shared
-obj-one-hundred
+create 100 shared 100 15
 ----
 <shared> create object "fd72-2-000100.sst"
 <shared> close writer for "fd72-2-000100.sst" after 15 bytes
@@ -118,25 +113,39 @@ list
 000103 -> shared://eaac-1-000003.sst
 
 read 101
+0 100
+15 10
 ----
 <shared> size of object "61a6-1-000001.sst.ref.2.000101": 0
-<shared> size of object "61a6-1-000001.sst": 7
-<shared> read object "61a6-1-000001.sst" at 0: 7 bytes
+<shared> size of object "61a6-1-000001.sst": 100
+size: 100
+<shared> read object "61a6-1-000001.sst" at 0: 100 bytes
+0 100: ok (salt 1)
+<shared> close reader for "61a6-1-000001.sst"
+<shared> read object "61a6-1-000001.sst" at 15: 85 bytes
+15 10: ok (salt 1)
 <shared> close reader for "61a6-1-000001.sst"
-data: obj-one
 
 read 102
+0 200
+90 100
 ----
 <shared> size of object "a629-1-000002.sst.ref.2.000102": 0
-<shared> size of object "a629-1-000002.sst": 7
-<shared> read object "a629-1-000002.sst" at 0: 7 bytes
+<shared> size of object "a629-1-000002.sst": 200
+size: 200
+<shared> read object "a629-1-000002.sst" at 0: 200 bytes
+0 200: ok (salt 2)
+<shared> close reader for "a629-1-000002.sst"
+<shared> read object "a629-1-000002.sst" at 90: 110 bytes
+90 100: ok (salt 2)
 <shared> close reader for "a629-1-000002.sst"
-data: obj-two
 
 read 103
+0 300
 ----
 <shared> size of object "eaac-1-000003.sst.ref.2.000103": 0
-<shared> size of object "eaac-1-000003.sst": 9
-<shared> read object "eaac-1-000003.sst" at 0: 9 bytes
+<shared> size of object "eaac-1-000003.sst": 300
+size: 300
+<shared> read object "eaac-1-000003.sst" at 0: 300 bytes
+0 300: ok (salt 3)
 <shared> close reader for "eaac-1-000003.sst"
-data: obj-three
diff --git a/objstorage/objstorageprovider/testdata/provider/shared_attach_after_unref b/objstorage/objstorageprovider/testdata/provider/shared_attach_after_unref
index 00d883f10a..d13f692fd4 100644
--- a/objstorage/objstorageprovider/testdata/provider/shared_attach_after_unref
+++ b/objstorage/objstorageprovider/testdata/provider/shared_attach_after_unref
@@ -12,11 +12,10 @@ open p5 5
 <local fs> sync: p5
 <local fs> sync: p5/SHARED-CATALOG-000001
 
-create 1 shared
-obj-one
+create 1 shared 1 100
 ----
 <shared> create object "d632-5-000001.sst"
-<shared> close writer for "d632-5-000001.sst" after 7 bytes
+<shared> close writer for "d632-5-000001.sst" after 100 bytes
 <shared> create object "d632-5-000001.sst.ref.5.000001"
 <shared> close writer for "d632-5-000001.sst.ref.5.000001" after 0 bytes
 
@@ -56,11 +55,10 @@ switch p5
 close-backing p5b1
 ----
 
-create 2 shared
-obj-two
+create 2 shared 2 100
 ----
 <shared> create object "1ab5-5-000002.sst"
-<shared> close writer for "1ab5-5-000002.sst" after 7 bytes
+<shared> close writer for "1ab5-5-000002.sst" after 100 bytes
 <shared> create object "1ab5-5-000002.sst.ref.5.000002"
 <shared> close writer for "1ab5-5-000002.sst.ref.5.000002" after 0 bytes
 
diff --git a/objstorage/objstorageprovider/testdata/provider/shared_attach_multi b/objstorage/objstorageprovider/testdata/provider/shared_attach_multi
index 013fe746a0..343cb4b8ab 100644
--- a/objstorage/objstorageprovider/testdata/provider/shared_attach_multi
+++ b/objstorage/objstorageprovider/testdata/provider/shared_attach_multi
@@ -12,11 +12,10 @@ open p1 1
 <local fs> sync: p1
 <local fs> sync: p1/SHARED-CATALOG-000001
 
-create 1 shared
-obj-one
+create 1 shared 1 100
 ----
 <shared> create object "61a6-1-000001.sst"
-<shared> close writer for "61a6-1-000001.sst" after 7 bytes
+<shared> close writer for "61a6-1-000001.sst" after 100 bytes
 <shared> create object "61a6-1-000001.sst.ref.1.000001"
 <shared> close writer for "61a6-1-000001.sst.ref.1.000001" after 0 bytes
 
diff --git a/objstorage/objstorageprovider/testdata/provider/shared_basic b/objstorage/objstorageprovider/testdata/provider/shared_basic
index a73efcf45d..e560eef520 100644
--- a/objstorage/objstorageprovider/testdata/provider/shared_basic
+++ b/objstorage/objstorageprovider/testdata/provider/shared_basic
@@ -13,32 +13,37 @@ open p1 1
 <local fs> sync: p1
 <local fs> sync: p1/SHARED-CATALOG-000001
 
-create 1 local
-obj-one
+create 1 local 1 100
 ----
 <local fs> create: p1/000001.sst
 <local fs> sync-data: p1/000001.sst
 <local fs> close: p1/000001.sst
 
 read 1
+0 100
 ----
-data: obj-one
+<local fs> open: p1/000001.sst
+size: 100
+<local fs> read-at(0, 100): p1/000001.sst
+0 100: ok (salt 1)
+<local fs> close: p1/000001.sst
 
-create 2 shared
-obj-two
+create 2 shared 2 100
 ----
 <shared> create object "a629-1-000002.sst"
-<shared> close writer for "a629-1-000002.sst" after 7 bytes
+<shared> close writer for "a629-1-000002.sst" after 100 bytes
 <shared> create object "a629-1-000002.sst.ref.1.000002"
 <shared> close writer for "a629-1-000002.sst.ref.1.000002" after 0 bytes
 
 read 2
+0 100
 ----
 <shared> size of object "a629-1-000002.sst.ref.1.000002": 0
-<shared> size of object "a629-1-000002.sst": 7
-<shared> read object "a629-1-000002.sst" at 0: 7 bytes
+<shared> size of object "a629-1-000002.sst": 100
+size: 100
+<shared> read object "a629-1-000002.sst" at 0: 100 bytes
+0 100: ok (salt 2)
 <shared> close reader for "a629-1-000002.sst"
-data: obj-two
 
 list
 ----
@@ -57,6 +62,8 @@ open p1 1
 <local fs> mkdir-all: p1 0755
 <local fs> open-dir: p1
 <local fs> open-dir: p1
+<local fs> open: p1/SHARED-CATALOG-000001
+<local fs> close: p1/SHARED-CATALOG-000001
 
 list
 ----
@@ -73,34 +80,41 @@ remove 2
 <shared> list (prefix="a629-1-000002.sst.ref.", delimiter="")
 <shared> delete object "a629-1-000002.sst"
 
-link-or-copy 3 local
-three
+link-or-copy 3 local 3 100
 ----
 <local fs> create: temp-file-1
 <local fs> close: temp-file-1
 <local fs> link: temp-file-1 -> p1/000003.sst
 
 read 3
+0 100
 ----
-data: three
+<local fs> open: p1/000003.sst
+size: 100
+<local fs> read-at(0, 100): p1/000003.sst
+0 100: ok (salt 3)
+<local fs> close: p1/000003.sst
 
-link-or-copy 4 shared
-four
+link-or-copy 4 shared 4 100
 ----
 <local fs> create: temp-file-2
 <local fs> close: temp-file-2
 <shared> create object "2f2f-1-000004.sst"
-<shared> close writer for "2f2f-1-000004.sst" after 4 bytes
+<local fs> open: temp-file-2
+<shared> close writer for "2f2f-1-000004.sst" after 100 bytes
 <shared> create object "2f2f-1-000004.sst.ref.1.000004"
 <shared> close writer for "2f2f-1-000004.sst.ref.1.000004" after 0 bytes
+<local fs> close: temp-file-2
 
 read 4
+0 100
 ----
 <shared> size of object "2f2f-1-000004.sst.ref.1.000004": 0
-<shared> size of object "2f2f-1-000004.sst": 4
-<shared> read object "2f2f-1-000004.sst" at 0: 4 bytes
+<shared> size of object "2f2f-1-000004.sst": 100
+size: 100
+<shared> read object "2f2f-1-000004.sst" at 0: 100 bytes
+0 100: ok (salt 4)
 <shared> close reader for "2f2f-1-000004.sst"
-data: four
 
 close
 ----
diff --git a/objstorage/objstorageprovider/testdata/provider/shared_no_ref b/objstorage/objstorageprovider/testdata/provider/shared_no_ref
index fa9d1e2b71..2f67a50ab9 100644
--- a/objstorage/objstorageprovider/testdata/provider/shared_no_ref
+++ b/objstorage/objstorageprovider/testdata/provider/shared_no_ref
@@ -13,51 +13,56 @@ open p1 1
 <local fs> sync: p1
 <local fs> sync: p1/SHARED-CATALOG-000001
 
-create 1 shared no-ref-tracking
-obj-one
+create 1 shared 1 100 no-ref-tracking
 ----
 <shared> create object "61a6-1-000001.sst"
-<shared> close writer for "61a6-1-000001.sst" after 7 bytes
+<shared> close writer for "61a6-1-000001.sst" after 100 bytes
 
 read 1
+0 100
 ----
-<shared> size of object "61a6-1-000001.sst": 7
-<shared> read object "61a6-1-000001.sst" at 0: 7 bytes
+<shared> size of object "61a6-1-000001.sst": 100
+size: 100
+<shared> read object "61a6-1-000001.sst" at 0: 100 bytes
+0 100: ok (salt 1)
 <shared> close reader for "61a6-1-000001.sst"
-data: obj-one
 
-create 2 shared no-ref-tracking
-obj-two
+create 2 shared 2 100 no-ref-tracking
 ----
 <shared> create object "a629-1-000002.sst"
-<shared> close writer for "a629-1-000002.sst" after 7 bytes
+<shared> close writer for "a629-1-000002.sst" after 100 bytes
 
 read 2
+0 100
 ----
-<shared> size of object "a629-1-000002.sst": 7
-<shared> read object "a629-1-000002.sst" at 0: 7 bytes
+<shared> size of object "a629-1-000002.sst": 100
+size: 100
+<shared> read object "a629-1-000002.sst" at 0: 100 bytes
+0 100: ok (salt 2)
 <shared> close reader for "a629-1-000002.sst"
-data: obj-two
 
 list
 ----
 000001 -> shared://61a6-1-000001.sst
 000002 -> shared://a629-1-000002.sst
 
-link-or-copy 3 shared no-ref-tracking
-obj-three
+link-or-copy 3 shared 3 100 no-ref-tracking
 ----
 <local fs> create: temp-file-1
 <local fs> close: temp-file-1
 <shared> create object "eaac-1-000003.sst"
-<shared> close writer for "eaac-1-000003.sst" after 9 bytes
+<local fs> open: temp-file-1
+<shared> close writer for "eaac-1-000003.sst" after 100 bytes
+<local fs> close: temp-file-1
 
 read 3
+0 100
 ----
-<shared> size of object "eaac-1-000003.sst": 9
-<shared> read object "eaac-1-000003.sst" at 0: 9 bytes
+<shared> size of object "eaac-1-000003.sst": 100
+size: 100
+<shared> read object "eaac-1-000003.sst" at 0: 100 bytes
+0 100: ok (salt 3)
 <shared> close reader for "eaac-1-000003.sst"
-data: obj-three
 
 close
 ----
@@ -70,6 +75,8 @@ open p1 1
 <local fs> mkdir-all: p1 0755
 <local fs> open-dir: p1
 <local fs> open-dir: p1
+<local fs> open: p1/SHARED-CATALOG-000001
+<local fs> close: p1/SHARED-CATALOG-000001
 
 list
 ----
@@ -78,25 +85,31 @@ list
 000003 -> shared://eaac-1-000003.sst
 
 read 1
+0 100
 ----
-<shared> size of object "61a6-1-000001.sst": 7
-<shared> read object "61a6-1-000001.sst" at 0: 7 bytes
+<shared> size of object "61a6-1-000001.sst": 100
+size: 100
+<shared> read object "61a6-1-000001.sst" at 0: 100 bytes
+0 100: ok (salt 1)
 <shared> close reader for "61a6-1-000001.sst"
-data: obj-one
 
 read 2
+0 100
 ----
-<shared> size of object "a629-1-000002.sst": 7
-<shared> read object "a629-1-000002.sst" at 0: 7 bytes
+<shared> size of object "a629-1-000002.sst": 100
+size: 100
+<shared> read object "a629-1-000002.sst" at 0: 100 bytes
+0 100: ok (salt 2)
 <shared> close reader for "a629-1-000002.sst"
-data: obj-two
 
 read 3
+0 100
 ----
-<shared> size of object "eaac-1-000003.sst": 9
-<shared> read object "eaac-1-000003.sst" at 0: 9 bytes
+<shared> size of object "eaac-1-000003.sst": 100
+size: 100
+<shared> read object "eaac-1-000003.sst" at 0: 100 bytes
+0 100: ok (salt 3)
 <shared> close reader for "eaac-1-000003.sst"
-data: obj-three
 
 save-backing b1 1
 ----
@@ -130,18 +143,22 @@ list
 000102 -> shared://61a6-1-000001.sst
 
 read 101
+0 100
 ----
-<shared> size of object "61a6-1-000001.sst": 7
-<shared> read object "61a6-1-000001.sst" at 0: 7 bytes
+<shared> size of object "61a6-1-000001.sst": 100
+size: 100
+<shared> read object "61a6-1-000001.sst" at 0: 100 bytes
+0 100: ok (salt 1)
 <shared> close reader for "61a6-1-000001.sst"
-data: obj-one
 
 read 102
+0 100
 ----
-<shared> size of object "61a6-1-000001.sst": 7
-<shared> read object "61a6-1-000001.sst" at 0: 7 bytes
+<shared> size of object "61a6-1-000001.sst": 100
+size: 100
+<shared> read object "61a6-1-000001.sst" at 0: 100 bytes
+0 100: ok (salt 1)
 <shared> close reader for "61a6-1-000001.sst"
-data: obj-one
 
 # In this mode, all removes should be no-ops on the shared backend.
 remove 101
diff --git a/objstorage/objstorageprovider/testdata/provider/shared_remove b/objstorage/objstorageprovider/testdata/provider/shared_remove
index 82c12946af..353cc04c8d 100644
--- a/objstorage/objstorageprovider/testdata/provider/shared_remove
+++ b/objstorage/objstorageprovider/testdata/provider/shared_remove
@@ -10,27 +10,24 @@ open p1 1
 <local fs> sync: p1
 <local fs> sync: p1/SHARED-CATALOG-000001
 
-create 1 shared
-obj-one
+create 1 shared 1 100
 ----
 <shared> create object "61a6-1-000001.sst"
-<shared> close writer for "61a6-1-000001.sst" after 7 bytes
+<shared> close writer for "61a6-1-000001.sst" after 100 bytes
 <shared> create object "61a6-1-000001.sst.ref.1.000001"
 <shared> close writer for "61a6-1-000001.sst.ref.1.000001" after 0 bytes
 
-create 2 shared
-obj-two
+create 2 shared 2 100
 ----
 <shared> create object "a629-1-000002.sst"
-<shared> close writer for "a629-1-000002.sst" after 7 bytes
+<shared> close writer for "a629-1-000002.sst" after 100 bytes
 <shared> create object "a629-1-000002.sst.ref.1.000002"
 <shared> close writer for "a629-1-000002.sst.ref.1.000002" after 0 bytes
 
-create 3 shared
-obj-three
+create 3 shared 3 100
 ----
 <shared> create object "eaac-1-000003.sst"
-<shared> close writer for "eaac-1-000003.sst" after 9 bytes
+<shared> close writer for "eaac-1-000003.sst" after 100 bytes
 <shared> create object "eaac-1-000003.sst.ref.1.000003"
 <shared> close writer for "eaac-1-000003.sst.ref.1.000003" after 0 bytes
 
@@ -52,11 +49,10 @@ open p2 2
 <local fs> sync: p2
 <local fs> sync: p2/SHARED-CATALOG-000001
 
-create 4 shared
-obj-four
+create 4 shared 4 100
 ----
 <shared> create object "4c52-2-000004.sst"
-<shared> close writer for "4c52-2-000004.sst" after 8 bytes
+<shared> close writer for "4c52-2-000004.sst" after 100 bytes
 <shared> create object "4c52-2-000004.sst.ref.2.000004"
 <shared> close writer for "4c52-2-000004.sst.ref.2.000004" after 0 bytes
 
diff --git a/objstorage/objstorageprovider/testdata/readahead b/objstorage/objstorageprovider/testdata/readahead
index 0bb7383b08..d2bb217314 100644
--- a/objstorage/objstorageprovider/testdata/readahead
+++ b/objstorage/objstorageprovider/testdata/readahead
@@ -1,3 +1,6 @@
+reset
+----
+
 read
 2048, 16
 ----
@@ -136,7 +139,7 @@ limit:      73216
 
 read
 7780, 16
-----
+---
 readahead:  0
 numReads:   4
 size:       131072
@@ -146,17 +149,13 @@ limit:      73216
 read
 7880, 16
 ----
-readahead:  0
-numReads:   5
-size:       131072
-prevSize:   65536
-limit:      73216
+expected 2 args: offset, size
 
 read
 7980, 16
 ----
 readahead:  0
-numReads:   6
+numReads:   4
 size:       131072
 prevSize:   65536
 limit:      73216
@@ -165,7 +164,7 @@ read
 73416, 16
 ----
 readahead:  131072
-numReads:   7
+numReads:   5
 size:       262144
 prevSize:   131072
 limit:      204488
@@ -174,7 +173,7 @@ read
 204488, 16
 ----
 readahead:  262144
-numReads:   8
+numReads:   6
 size:       262144
 prevSize:   262144
 limit:      466632
@@ -185,7 +184,7 @@ read
 466632, 16
 ----
 readahead:  262144
-numReads:   9
+numReads:   7
 size:       262144
 prevSize:   262144
 limit:      728776
@@ -196,7 +195,7 @@ cache-read
 728770, 16
 ----
 readahead:  0
-numReads:   9
+numReads:   7
 size:       262144
 prevSize:   262144
 limit:      728786
@@ -205,7 +204,7 @@ read
 728780, 16
 ----
 readahead:  262144
-numReads:   10
+numReads:   8
 size:       262144
 prevSize:   262144
 limit:      990924
diff --git a/testdata/checkpoint b/testdata/checkpoint
index ead1c79df8..131e6ebacc 100644
--- a/testdata/checkpoint
+++ b/testdata/checkpoint
@@ -5,6 +5,7 @@ open-dir: db
 lock: db/LOCK
 open-dir: db
 open-dir: db
+open: db/CURRENT
 create: db/MANIFEST-000001
 sync: db/MANIFEST-000001
 remove: db/temporary.000001.dbtmp
@@ -145,18 +146,22 @@ sync: checkpoints/checkpoint1
 close: checkpoints/checkpoint1
 link: db/000005.sst -> checkpoints/checkpoint1/000005.sst
 link: db/000007.sst -> checkpoints/checkpoint1/000007.sst
+open: db/MANIFEST-000001
 create: checkpoints/checkpoint1/MANIFEST-000001
 sync-data: checkpoints/checkpoint1/MANIFEST-000001
 close: checkpoints/checkpoint1/MANIFEST-000001
+close: db/MANIFEST-000001
 open-dir: checkpoints/checkpoint1
 create: checkpoints/checkpoint1/marker.manifest.000001.MANIFEST-000001
 sync-data: checkpoints/checkpoint1/marker.manifest.000001.MANIFEST-000001
 close: checkpoints/checkpoint1/marker.manifest.000001.MANIFEST-000001
 sync: checkpoints/checkpoint1
 close: checkpoints/checkpoint1
+open: db/000006.log
 create: checkpoints/checkpoint1/000006.log
 sync-data: checkpoints/checkpoint1/000006.log
 close: checkpoints/checkpoint1/000006.log
+close: db/000006.log
 sync: checkpoints/checkpoint1
 close: checkpoints/checkpoint1
 
@@ -180,18 +185,22 @@ close: checkpoints/checkpoint2/marker.format-version.000001.014
 sync: checkpoints/checkpoint2
 close: checkpoints/checkpoint2
 link: db/000007.sst -> checkpoints/checkpoint2/000007.sst
+open: db/MANIFEST-000001
 create: checkpoints/checkpoint2/MANIFEST-000001
 sync-data: checkpoints/checkpoint2/MANIFEST-000001
 close: checkpoints/checkpoint2/MANIFEST-000001
+close: db/MANIFEST-000001
 open-dir: checkpoints/checkpoint2
 create: checkpoints/checkpoint2/marker.manifest.000001.MANIFEST-000001
 sync-data: checkpoints/checkpoint2/marker.manifest.000001.MANIFEST-000001
 close: checkpoints/checkpoint2/marker.manifest.000001.MANIFEST-000001
 sync: checkpoints/checkpoint2
 close: checkpoints/checkpoint2
+open: db/000006.log
 create: checkpoints/checkpoint2/000006.log
 sync-data: checkpoints/checkpoint2/000006.log
 close: checkpoints/checkpoint2/000006.log
+close: db/000006.log
 sync: checkpoints/checkpoint2
 close: checkpoints/checkpoint2
 
@@ -212,18 +221,22 @@ sync: checkpoints/checkpoint3
 close: checkpoints/checkpoint3
 link: db/000005.sst -> checkpoints/checkpoint3/000005.sst
 link: db/000007.sst -> checkpoints/checkpoint3/000007.sst
+open: db/MANIFEST-000001
 create: checkpoints/checkpoint3/MANIFEST-000001
 sync-data: checkpoints/checkpoint3/MANIFEST-000001
 close: checkpoints/checkpoint3/MANIFEST-000001
+close: db/MANIFEST-000001
 open-dir: checkpoints/checkpoint3
 create: checkpoints/checkpoint3/marker.manifest.000001.MANIFEST-000001
 sync-data: checkpoints/checkpoint3/marker.manifest.000001.MANIFEST-000001
 close: checkpoints/checkpoint3/marker.manifest.000001.MANIFEST-000001
 sync: checkpoints/checkpoint3
 close: checkpoints/checkpoint3
+open: db/000006.log
 create: checkpoints/checkpoint3/000006.log
 sync-data: checkpoints/checkpoint3/000006.log
 close: checkpoints/checkpoint3/000006.log
+close: db/000006.log
 sync: checkpoints/checkpoint3
 close: checkpoints/checkpoint3
 
@@ -238,11 +251,44 @@ sync-data: db/000009.sst
 close: db/000009.sst
 sync: db
 sync: db/MANIFEST-000001
+open: db/000005.sst
+read-at(744, 53): db/000005.sst
+read-at(707, 37): db/000005.sst
+read-at(79, 628): db/000005.sst
+read-at(52, 27): db/000005.sst
+open: db/000005.sst
+close: db/000005.sst
+open: db/000009.sst
+read-at(732, 53): db/000009.sst
+read-at(695, 37): db/000009.sst
+read-at(67, 628): db/000009.sst
+read-at(40, 27): db/000009.sst
+open: db/000009.sst
+close: db/000009.sst
+open: db/000007.sst
+read-at(744, 53): db/000007.sst
+read-at(707, 37): db/000007.sst
+read-at(79, 628): db/000007.sst
+read-at(52, 27): db/000007.sst
+open: db/000007.sst
+close: db/000007.sst
+open: db/000005.sst
+read-at(0, 52): db/000005.sst
+open: db/000007.sst
+read-at(0, 52): db/000007.sst
 create: db/000010.sst
+close: db/000005.sst
+open: db/000009.sst
+read-at(0, 40): db/000009.sst
+close: db/000007.sst
+close: db/000009.sst
 sync-data: db/000010.sst
 close: db/000010.sst
 sync: db
 sync: db/MANIFEST-000001
+close: db/000005.sst
+close: db/000007.sst
+close: db/000009.sst
 remove: db/000005.sst
 remove: db/000007.sst
 remove: db/000009.sst
@@ -280,10 +326,28 @@ open-dir: checkpoints/checkpoint1
 lock: checkpoints/checkpoint1/LOCK
 open-dir: checkpoints/checkpoint1
 open-dir: checkpoints/checkpoint1
+open: checkpoints/checkpoint1/MANIFEST-000001
+close: checkpoints/checkpoint1/MANIFEST-000001
 open-dir: checkpoints/checkpoint1
+open: checkpoints/checkpoint1/OPTIONS-000003
+close: checkpoints/checkpoint1/OPTIONS-000003
+open: checkpoints/checkpoint1/000006.log
+close: checkpoints/checkpoint1/000006.log
 
 scan checkpoints/checkpoint1
 ----
+open: checkpoints/checkpoint1/000007.sst
+read-at(744, 53): checkpoints/checkpoint1/000007.sst
+read-at(707, 37): checkpoints/checkpoint1/000007.sst
+read-at(79, 628): checkpoints/checkpoint1/000007.sst
+read-at(52, 27): checkpoints/checkpoint1/000007.sst
+read-at(0, 52): checkpoints/checkpoint1/000007.sst
+open: checkpoints/checkpoint1/000005.sst
+read-at(744, 53): checkpoints/checkpoint1/000005.sst
+read-at(707, 37): checkpoints/checkpoint1/000005.sst
+read-at(79, 628): checkpoints/checkpoint1/000005.sst
+read-at(52, 27): checkpoints/checkpoint1/000005.sst
+read-at(0, 52): checkpoints/checkpoint1/000005.sst
 a 1
 b 5
 c 3
@@ -295,6 +359,12 @@ g 10
 
 scan db
 ----
+open: db/000010.sst
+read-at(766, 53): db/000010.sst
+read-at(729, 37): db/000010.sst
+read-at(101, 628): db/000010.sst
+read-at(74, 27): db/000010.sst
+read-at(0, 74): db/000010.sst
 a 1
 b 5
 c 3
@@ -321,10 +391,22 @@ open-dir: checkpoints/checkpoint2
 lock: checkpoints/checkpoint2/LOCK
 open-dir: checkpoints/checkpoint2
 open-dir: checkpoints/checkpoint2
+open: checkpoints/checkpoint2/MANIFEST-000001
+close: checkpoints/checkpoint2/MANIFEST-000001
 open-dir: checkpoints/checkpoint2
+open: checkpoints/checkpoint2/OPTIONS-000003
+close: checkpoints/checkpoint2/OPTIONS-000003
+open: checkpoints/checkpoint2/000006.log
+close: checkpoints/checkpoint2/000006.log
 
 scan checkpoints/checkpoint2
 ----
+open: checkpoints/checkpoint2/000007.sst
+read-at(744, 53): checkpoints/checkpoint2/000007.sst
+read-at(707, 37): checkpoints/checkpoint2/000007.sst
+read-at(79, 628): checkpoints/checkpoint2/000007.sst
+read-at(52, 27): checkpoints/checkpoint2/000007.sst
+read-at(0, 52): checkpoints/checkpoint2/000007.sst
 b 5
 d 7
 e 8
@@ -349,10 +431,28 @@ open-dir: checkpoints/checkpoint3
 lock: checkpoints/checkpoint3/LOCK
 open-dir: checkpoints/checkpoint3
 open-dir: checkpoints/checkpoint3
+open: checkpoints/checkpoint3/MANIFEST-000001
+close: checkpoints/checkpoint3/MANIFEST-000001
 open-dir: checkpoints/checkpoint3
+open: checkpoints/checkpoint3/OPTIONS-000003
+close: checkpoints/checkpoint3/OPTIONS-000003
+open: checkpoints/checkpoint3/000006.log
+close: checkpoints/checkpoint3/000006.log
 
 scan checkpoints/checkpoint3
 ----
+open: checkpoints/checkpoint3/000007.sst
+read-at(744, 53): checkpoints/checkpoint3/000007.sst
+read-at(707, 37): checkpoints/checkpoint3/000007.sst
+read-at(79, 628): checkpoints/checkpoint3/000007.sst
+read-at(52, 27): checkpoints/checkpoint3/000007.sst
+read-at(0, 52): checkpoints/checkpoint3/000007.sst
+open: checkpoints/checkpoint3/000005.sst
+read-at(744, 53): checkpoints/checkpoint3/000005.sst
+read-at(707, 37): checkpoints/checkpoint3/000005.sst
+read-at(79, 628): checkpoints/checkpoint3/000005.sst
+read-at(52, 27): checkpoints/checkpoint3/000005.sst
+read-at(0, 52): checkpoints/checkpoint3/000005.sst
 a 1
 b 5
 c 3
diff --git a/testdata/cleaner b/testdata/cleaner
index e5b4059cbc..cd96e7d2fb 100644
--- a/testdata/cleaner
+++ b/testdata/cleaner
@@ -8,6 +8,7 @@ open-dir: db_wal
 lock: db/LOCK
 open-dir: db
 open-dir: db
+open: db/CURRENT
 create: db/MANIFEST-000001
 sync: db/MANIFEST-000001
 remove: db/temporary.000001.dbtmp
@@ -65,11 +66,33 @@ sync: db
 sync: db/MANIFEST-000001
 mkdir-all: db_wal/archive 0755
 rename: db_wal/000004.log -> db_wal/archive/000004.log
+open: db/000005.sst
+read-at(744, 53): db/000005.sst
+read-at(707, 37): db/000005.sst
+read-at(79, 628): db/000005.sst
+read-at(52, 27): db/000005.sst
+open: db/000005.sst
+close: db/000005.sst
+open: db/000007.sst
+read-at(718, 53): db/000007.sst
+read-at(681, 37): db/000007.sst
+read-at(53, 628): db/000007.sst
+read-at(26, 27): db/000007.sst
+open: db/000007.sst
+close: db/000007.sst
+open: db/000005.sst
+read-at(0, 52): db/000005.sst
 create: db/000008.sst
+close: db/000005.sst
+open: db/000007.sst
+read-at(0, 26): db/000007.sst
+close: db/000007.sst
 sync-data: db/000008.sst
 close: db/000008.sst
 sync: db
 sync: db/MANIFEST-000001
+close: db/000005.sst
+close: db/000007.sst
 mkdir-all: db/archive 0755
 rename: db/000005.sst -> db/archive/000005.sst
 mkdir-all: db/archive 0755
@@ -109,6 +132,7 @@ open-dir: db1_wal
 lock: db1/LOCK
 open-dir: db1
 open-dir: db1
+open: db1/CURRENT
 create: db1/MANIFEST-000001
 sync: db1/MANIFEST-000001
 remove: db1/temporary.000001.dbtmp
@@ -178,7 +202,16 @@ open-dir: db1_wal
 lock: db1/LOCK
 open-dir: db1
 open-dir: db1
+open: db1/CURRENT
+read-at(0, 16): db1/CURRENT
+close: db1/CURRENT
+open: db1/MANIFEST-000001
+close: db1/MANIFEST-000001
 open-dir: db1
+open: db1/OPTIONS-000003
+close: db1/OPTIONS-000003
+open: db1_wal/000004.log
+close: db1_wal/000004.log
 create: db1/MANIFEST-000458
 sync: db1/MANIFEST-000458
 remove: db1/temporary.000458.dbtmp
diff --git a/testdata/event_listener b/testdata/event_listener
index 9785c3e820..afdc789b40 100644
--- a/testdata/event_listener
+++ b/testdata/event_listener
@@ -7,6 +7,7 @@ open-dir: wal
 lock: db/LOCK
 open-dir: db
 open-dir: db
+open: db/CURRENT
 create: db/MANIFEST-000001
 sync: db/MANIFEST-000001
 remove: db/temporary.000001.dbtmp
@@ -149,6 +150,26 @@ sync: db
 remove: db/MANIFEST-000001
 [JOB 7] MANIFEST deleted 000001
 [JOB 8] compacting(default) L0 [000005 000008] (1.5 K) + L6 [] (0 B)
+open: db/000005.sst
+read-at(717, 53): db/000005.sst
+read-at(680, 37): db/000005.sst
+read-at(52, 628): db/000005.sst
+read-at(25, 27): db/000005.sst
+open: db/000005.sst
+close: db/000005.sst
+open: db/000008.sst
+read-at(717, 53): db/000008.sst
+read-at(680, 37): db/000008.sst
+read-at(52, 628): db/000008.sst
+read-at(25, 27): db/000008.sst
+open: db/000008.sst
+close: db/000008.sst
+open: db/000005.sst
+read-at(0, 25): db/000005.sst
+open: db/000008.sst
+read-at(0, 25): db/000008.sst
+close: db/000008.sst
+close: db/000005.sst
 create: db/000010.sst
 [JOB 8] compacting: sstable created 000010
 sync-data: db/000010.sst
@@ -163,6 +184,8 @@ remove: db/marker.manifest.000003.MANIFEST-000009
 sync: db
 [JOB 8] MANIFEST created 000011
 [JOB 8] compacted(default) L0 [000005 000008] (1.5 K) + L6 [] (0 B) -> L6 [000010] (770 B), in 1.0s (3.0s total), output rate 770 B/s
+close: db/000005.sst
+close: db/000008.sst
 remove: db/000005.sst
 [JOB 8] sstable deleted 000005
 remove: db/000008.sst
@@ -204,9 +227,22 @@ remove: db/MANIFEST-000009
 
 ingest
 ----
+open: ext/0
+read-at(773, 53): ext/0
+read-at(736, 37): ext/0
+read-at(53, 683): ext/0
+read-at(26, 27): ext/0
+read-at(0, 26): ext/0
+close: ext/0
 link: ext/0 -> db/000015.sst
 [JOB 12] ingesting: sstable created 000015
 sync: db
+open: db/000013.sst
+read-at(717, 53): db/000013.sst
+read-at(680, 37): db/000013.sst
+read-at(52, 628): db/000013.sst
+read-at(25, 27): db/000013.sst
+read-at(0, 25): db/000013.sst
 create: db/MANIFEST-000016
 close: db/MANIFEST-000014
 sync: db/MANIFEST-000016
@@ -249,6 +285,20 @@ zmemtbl         0     0 B
 ingest-flushable
 ----
 sync-data: wal/000012.log
+open: ext/a
+read-at(773, 53): ext/a
+read-at(736, 37): ext/a
+read-at(53, 683): ext/a
+read-at(26, 27): ext/a
+read-at(0, 26): ext/a
+close: ext/a
+open: ext/b
+read-at(773, 53): ext/b
+read-at(736, 37): ext/b
+read-at(53, 683): ext/b
+read-at(26, 27): ext/b
+read-at(0, 26): ext/b
+close: ext/b
 link: ext/a -> db/000017.sst
 [JOB 13] ingesting: sstable created 000017
 link: ext/b -> db/000018.sst
@@ -354,18 +404,22 @@ link: db/000022.sst -> checkpoint/000022.sst
 link: db/000017.sst -> checkpoint/000017.sst
 link: db/000010.sst -> checkpoint/000010.sst
 link: db/000018.sst -> checkpoint/000018.sst
+open: db/MANIFEST-000023
 create: checkpoint/MANIFEST-000023
 sync-data: checkpoint/MANIFEST-000023
 close: checkpoint/MANIFEST-000023
+close: db/MANIFEST-000023
 open-dir: checkpoint
 create: checkpoint/marker.manifest.000001.MANIFEST-000023
 sync-data: checkpoint/marker.manifest.000001.MANIFEST-000023
 close: checkpoint/marker.manifest.000001.MANIFEST-000023
 sync: checkpoint
 close: checkpoint
+open: wal/000021.log
 create: checkpoint/000021.log
 sync-data: checkpoint/000021.log
 close: checkpoint/000021.log
+close: wal/000021.log
 sync: checkpoint
 close: checkpoint
 
@@ -376,6 +430,7 @@ pebble: file deletion disablement invariant violated
 close
 ----
 close: db
+close: db/000013.sst
 sync-data: wal/000021.log
 close: wal/000021.log
 close: db/MANIFEST-000023
diff --git a/vfs/logging_fs.go b/vfs/logging_fs.go
index ee0c3e281c..3ba558458f 100644
--- a/vfs/logging_fs.go
+++ b/vfs/logging_fs.go
@@ -37,6 +37,15 @@ func (fs *loggingFS) Create(name string) (File, error) {
 	return newLoggingFile(f, name, fs.logFn), nil
 }
 
+func (fs *loggingFS) Open(name string, opts ...OpenOption) (File, error) {
+	fs.logFn("open: %s", name)
+	f, err := fs.FS.Open(name, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return newLoggingFile(f, name, fs.logFn), nil
+}
+
 func (fs *loggingFS) Link(oldname, newname string) error {
 	fs.logFn("link: %s -> %s", oldname, newname)
 	return fs.FS.Link(oldname, newname)
@@ -122,3 +131,13 @@ func (f *loggingFile) SyncTo(length int64) (fullSync bool, err error) {
 	f.logFn("sync-to(%d): %s", length, f.name)
 	return f.File.SyncTo(length)
 }
+
+func (f *loggingFile) ReadAt(p []byte, offset int64) (int, error) {
+	f.logFn("read-at(%d, %d): %s", offset, len(p), f.name)
+	return f.File.ReadAt(p, offset)
+}
+
+func (f *loggingFile) Prefetch(offset int64, length int64) error {
+	f.logFn("prefetch(%d, %d): %s", offset, length, f.name)
+	return f.File.Prefetch(offset, length)
+}