diff --git a/CHANGELOG.md b/CHANGELOG.md
index 22b628797fd75b1098ba6be0d1286b9b5940110f..a792df8a15f0db0c2cbaeb5cf95bedf825ce9813 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,8 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   - Tests to cover proxy and (malleability) ([!222](https://storage.bsc.es/gitlab/hpc/gekkofs/-/merge_requests/222))
   - New fd generation method ([!225](https://storage.bsc.es/gitlab/hpc/gekkofs/-/merge_requests/202))
     - Use LIBGKFS_PROTECT_FD=1 to enable the original method of assignation and protection.
+    - Use LIBGKFS_RANGE_FD=1 to enable virtual fds from 10000, but without protecting and relocating fds. 
+      - ([!251](https://storage.bsc.es/gitlab/hpc/gekkofs/-/merge_requests/251))
   - Lock system (server level) ([!245](https://storage.bsc.es/gitlab/hpc/gekkofs/-/merge_requests/245))
     - Use PROTECT_FILES_GENERATOR=1 and PROTECT_FILES_CONSUMER=1 to enable. Generator, creates transparent .lockgekko files that blocks the open (for some seconds) of any consumer. Multiple opens / closes for generator are managed.
   - Basic mmap support ([!247](https://storage.bsc.es/gitlab/hpc/gekkofs/-/merge_requests/245))
diff --git a/README.md b/README.md
index c15fd6f9a10fe059fee0ff541c82e1d75d483fd0..88b0b86d3a600a4a367b622f7014e1693400fe35 100644
--- a/README.md
+++ b/README.md
@@ -610,6 +610,7 @@ until the file is closed. The cache does not impact the consistency of the file
 ##### Protecting FDs
 When the user creates a fd, this is protected from normal fds with a recolocation. This theoretically protects the fd from being closed from outside. However a new fd assignation system has been developed and is activated by default.
 - `LIBGKFS_PROTECT_FD=1` - Enable the original method of assignation and protection.
+- `LIBGKFS_RANGE_FD=1`- Enables FDs from 10000, virtual, but does not protect them.
 
 ##### Lightweight File-Locking (server side)
 Using two environment variables
diff --git a/include/client/env.hpp b/include/client/env.hpp
index 5140d8f1110ab8a82288415f059c47b34c7f2cc7..e64fa5db380e799e002fb08cf6cdb681595d27ba 100644
--- a/include/client/env.hpp
+++ b/include/client/env.hpp
@@ -73,6 +73,8 @@ static constexpr auto PROTECT_FILES_GENERATOR =
         ADD_PREFIX("PROTECT_FILES_GENERATOR");
 static constexpr auto PROTECT_FILES_CONSUMER =
         ADD_PREFIX("PROTECT_FILES_CONSUMER");
+static constexpr auto RANGE_FD = ADD_PREFIX("RANGE_FD");
+
 static constexpr auto NUM_REPL = ADD_PREFIX("NUM_REPL");
 static constexpr auto PROXY_PID_FILE = ADD_PREFIX("PROXY_PID_FILE");
 namespace cache {
diff --git a/include/client/preload_context.hpp b/include/client/preload_context.hpp
index 245e15c28fcf80c21e10922c9cb5be71308a73bc..434ac707fdc7b587109f47afc1b617b14b53947c 100644
--- a/include/client/preload_context.hpp
+++ b/include/client/preload_context.hpp
@@ -142,6 +142,8 @@ private:
     bool protect_fds_{false};
     bool protect_files_generator_{false};
     bool protect_files_consumer_{false};
+    bool range_fd_{false};
+
 
     std::shared_ptr<gkfs::messagepack::ClientMetrics> write_metrics_;
     std::shared_ptr<gkfs::messagepack::ClientMetrics> read_metrics_;
@@ -336,6 +338,12 @@ public:
     void
     protect_files_consumer(bool protect);
 
+    bool
+    range_fd() const;
+
+    void
+    range_fd(bool fd);
+
     const std::shared_ptr<gkfs::messagepack::ClientMetrics>
     write_metrics();
 
diff --git a/src/client/open_file_map.cpp b/src/client/open_file_map.cpp
index 1a5193a45a45004063141e136da00ae5001cee0c..c54020660e0dbd3a17d54f8cf1283eb4efe71648 100644
--- a/src/client/open_file_map.cpp
+++ b/src/client/open_file_map.cpp
@@ -162,7 +162,16 @@ OpenFileMap::safe_generate_fd_idx_() {
             }
         }
     } else {
-        // Some architectures do not support SYS_open
+        // Return a virtual fd from 10000, but avoid doing all the FD movements
+        if(CTX->range_fd()) {
+            if(fd_validation_needed) {
+                while(exist(fd)) {
+                    fd = generate_fd_idx();
+                }
+            }
+            return fd;
+        }
+
         fd = syscall_no_intercept(SYS_openat, AT_FDCWD, "/dev/null", O_RDWR,
                                   S_IRUSR | S_IWUSR);
     }
@@ -185,9 +194,13 @@ OpenFileMap::remove(const int fd) {
         return false;
     }
     files_.erase(fd);
+
     if(!CTX->protect_fds()) {
-        // We close the dev null fd
-        close(fd);
+        if(!CTX->range_fd()) {
+            // We close the dev null fd
+            close(fd);
+            return true;
+        }
     }
     if(fd_validation_needed && files_.empty()) {
         fd_validation_needed = false;
diff --git a/src/client/preload.cpp b/src/client/preload.cpp
index 76426a89c54e1eb814bf3d9ec415968c270ac3c4..dc8a4dabfea5e65055e91d35abda7af4b6e2e809 100644
--- a/src/client/preload.cpp
+++ b/src/client/preload.cpp
@@ -398,6 +398,11 @@ init_preload() {
     if(gkfs::env::var_is_set(gkfs::env::PROTECT_FD)) {
         CTX->protect_fds(true);
         LOG(INFO, "Protecting user fds");
+    } else {
+        // Another alternative is to use start issuing fds from gekko from a
+        // offset. but without protecting the FDs
+        CTX->range_fd(gkfs::env::var_is_set(gkfs::env::RANGE_FD));
+        LOG(INFO, "Moving FDs to range");
     }
 
     if(CTX->protect_fds()) {
diff --git a/src/client/preload_context.cpp b/src/client/preload_context.cpp
index 7a0f49f18cf9e7e570ba76fb453465a9c221aec1..465ed926fb4bb1ccbbad03cdaa4ed7629730aca4 100644
--- a/src/client/preload_context.cpp
+++ b/src/client/preload_context.cpp
@@ -677,6 +677,16 @@ PreloadContext::protect_files_consumer(bool protect) {
     protect_files_consumer_ = protect;
 }
 
+bool
+PreloadContext::range_fd() const {
+    return range_fd_;
+}
+
+void
+PreloadContext::range_fd(bool fd) {
+    range_fd_ = fd;
+}
+
 
 const std::shared_ptr<messagepack::ClientMetrics>
 PreloadContext::write_metrics() {
diff --git a/tests/apps/CMakeLists.txt b/tests/apps/CMakeLists.txt
index ecbcc9f41e7104a75a4be9a5441d644c11bedef2..e79fd67bdd439f472a2f3a83075544f8f1de0aad 100644
--- a/tests/apps/CMakeLists.txt
+++ b/tests/apps/CMakeLists.txt
@@ -26,67 +26,51 @@
 # SPDX-License-Identifier: GPL-3.0-or-later                                    #
 ################################################################################
 
-add_test(
-  NAME s3d_io_test
-  COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/s3d-io.sh
-)
+# --- Common Test Properties ---
+set(DEFAULT_TEST_TIMEOUT 9000)
+set(DEFAULT_TEST_LABELS "apps::all")
+set(DEFAULT_TEST_WORKING_DIR ${CMAKE_CURRENT_BINARY_DIR})
 
-# Optionally set test properties (timeout, environment, etc.)
-set_tests_properties(s3d_io_test
-  PROPERTIES
-    TIMEOUT 9000
-    LABELS "apps::all"
-    # ENVIRONMENT "LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu/fortran/gfortran-mod-15:$ENV{LD_LIBRARY_PATH}"
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-)
+# --- Helper Function to Add Tests with Common Properties ---
+# This function simplifies adding new tests that share common properties.
+# Usage: gekko_add_test(<test_name> <script_name.sh> [EXTRA_PROPERTIES <prop1> <val1> ...])
+function(gekko_add_test TEST_NAME SCRIPT_FILENAME)
+    add_test(
+        NAME ${TEST_NAME}
+        COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/${SCRIPT_FILENAME}
+        WORKING_DIRECTORY ${DEFAULT_TEST_WORKING_DIR} 
+    )
+
+    set_tests_properties(${TEST_NAME}
+        PROPERTIES
+            TIMEOUT ${DEFAULT_TEST_TIMEOUT}
+            LABELS ${DEFAULT_TEST_LABELS}
+    )
+endfunction()
 
-add_test(
-  NAME s3d_io_test_large
-  COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/s3d-io-large.sh
-)
 
-# Optionally set test properties (timeout, environment, etc.)
-set_tests_properties(s3d_io_test_large
-  PROPERTIES
-    TIMEOUT 9000
-    LABELS "apps::all"
-    # ENVIRONMENT "LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu/fortran/gfortran-mod-15:$ENV{LD_LIBRARY_PATH}"
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-)
+# --- Test Definitions ---
+gekko_add_test(s3d_io_test s3d-io.sh)
+# To add the specific environment for this test (if needed):
+# set_tests_properties(s3d_io_test APPEND PROPERTIES ENVIRONMENT "${FORTRAN_TEST_ENV}")
 
-add_test(
-  NAME wacomm
-  COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/wacomm.sh
-)
+gekko_add_test(s3d_io_test_environment s3d-io-env.sh)
 
-# Optionally set test properties (timeout, environment, etc.)
-set_tests_properties(wacomm
-  PROPERTIES
-    TIMEOUT 9000
-    LABELS "apps::all"
-    # ENVIRONMENT "LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu/fortran/gfortran-mod-15:$ENV{LD_LIBRARY_PATH}"
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-)
+gekko_add_test(s3d_io_test_large s3d-io-large.sh)
 
-add_test(
-  NAME lockfile
-  COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/lockfile.sh
-)
+gekko_add_test(wacomm wacomm.sh)
 
-set_tests_properties(lockfile
-  PROPERTIES
-    TIMEOUT 9000
-    LABELS "apps::all"
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-)
+gekko_add_test(lockfile lockfile.sh)
 
 
+# --- Installation of Test Scripts ---
 if(GKFS_INSTALL_TESTS)
-    install(DIRECTORY .
+    install(
+        DIRECTORY . # Installs files from the current source directory
         DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/gkfs/tests/apps
         FILE_PERMISSIONS OWNER_READ OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
         FILES_MATCHING
-        PATTERN "*.sh"
-        PATTERN "*" EXCLUDE
+            PATTERN "*.sh" # Only install .sh files
+
     )
 endif()
\ No newline at end of file
diff --git a/tests/apps/s3d-io-env.sh b/tests/apps/s3d-io-env.sh
new file mode 100755
index 0000000000000000000000000000000000000000..776e39162b3b6989c877632a6d9bacd0fbfccd0f
--- /dev/null
+++ b/tests/apps/s3d-io-env.sh
@@ -0,0 +1,129 @@
+#!/bin/bash
+
+# Typical command line :  /builds/gitlab/hpc/gekkofs/gkfs/install/bin/gkfs_daemon --mountdir /builds/gitlab/hpc/gekkofs/gkfs/build/tests/run/popen-gw0/test_write_gkfs_daemon_rocksdb0/mnt --rootdir /builds/gitlab/hpc/gekkofs/gkfs/build/tests/run/popen-gw0/test_write_gkfs_daemon_rocksdb0/root -l lo:22543 --metadir /builds/gitlab/hpc/gekkofs/gkfs/build/tests/run/popen-gw0/test_write_gkfs_daemon_rocksdb0/root --dbbackend rocksdb --output-stats /builds/gitlab/hpc/gekkofs/gkfs/build/tests/run/popen-gw0/test_write_gkfs_daemon_rocksdb0/logs/stats.log --enable-collection --enable-chunkstats
+
+## Environment variables
+export IO=/builds/gitlab/hpc/gekkofs/gkfs/install
+export GKFS=$IO/lib/libgkfs_intercept.so
+export GKFS_LIBC=$IO/lib/libgkfs_libc_intercept.so
+export DAEMON=$IO/bin/gkfs_daemon
+
+export OUTSIDE=$IO/tests/app/s3d-env/original
+export MNT=$IO/tests/app/s3d-env/mnt
+export ROOT=$IO/tests/app/s3d-env/root
+export GKFS_HOSTS_FILE=$ROOT/gkfs_hosts_s3d_env.txt
+export LIBGKFS_HOSTS_FILE=$GKFS_HOSTS_FILE
+export LD_LIBRARY_PATH=/root/wacommplusplus/build/external/lib:$IO/lib/:$LD_LIBRARY_PATH
+export APP=/root/S3D-IO/s3d_io.x
+export PARAMS="10 10 10 1 1 1 0 F"
+
+rm -rf $MNT
+rm -rf $ROOT
+
+mkdir -p $MNT $ROOT
+
+# Start gkfs_daemon in the background
+echo "Starting gkfs_daemon..."
+$DAEMON -r $ROOT -m $MNT  &
+DAEMON_PID=$!
+
+sleep 5
+
+# Check if the daemon is running
+if ! ps -p $DAEMON_PID > /dev/null; then
+  echo "Error: gkfs_daemon failed to start! PID: $DAEMON_PID"
+  exit 1
+fi
+
+
+# Run s3d-io.x with LD_PRELOAD and capture exit code
+echo "Running s3d-io.x..."
+
+LD_PRELOAD=$GKFS mkdir $MNT/syscall $MNT/libc $OUTSIDE
+
+echo "Step 1 - PROTECT_FDs "
+
+LIBGKFS_PROTECT_FD=1 LD_PRELOAD=$GKFS $APP $PARAMS $MNT/syscall
+
+LIBGKFS_PROTECT_FD=1  LD_PRELOAD=$GKFS_LIBC $APP $PARAMS $MNT/libc
+
+$APP $PARAMS $OUTSIDE 2>&1 > /dev/null
+
+compare_sizes() {
+diff -q <(find "$1" -type f -exec stat -c%s {} + | sort -k2) <(find "$2" -type f -exec stat -c%s {} + | sort -k2)
+}
+export LD_PRELOAD=$GKFS
+compare_sizes "$OUTSIDE" "$MNT/libc"
+TEST_DIFF1_PROTECT_FD=$?
+
+compare_sizes "$OUTSIDE" "$MNT/syscall"
+TEST_DIFF2_PROTECT_FD=$?
+unset LD_PRELOAD
+# remove costly data
+LD_PRELOAD=$GKFS rm -rf $OUTSIDE
+LD_PRELOAD=$GKFS rm -rf $MNT/libc
+LD_PRELOAD=$GKFS rm -rf $MNT/syscall
+
+LD_PRELOAD=$GKFS mkdir $MNT/syscall $MNT/libc $OUTSIDE
+
+echo "Step 2 - RANGE_FDs "
+
+LIBGKFS_RANGE_FD=1 LD_PRELOAD=$GKFS $APP $PARAMS $MNT/syscall
+
+LIBGKFS_RANGE_FD=1 LD_PRELOAD=$GKFS_LIBC $APP $PARAMS $MNT/libc
+
+$APP $PARAMS $OUTSIDE 2>&1 > /dev/null
+
+compare_sizes() {
+diff -q <(find "$1" -type f -exec stat -c%s {} + | sort -k2) <(find "$2" -type f -exec stat -c%s {} + | sort -k2)
+}
+export LD_PRELOAD=$GKFS
+compare_sizes "$OUTSIDE" "$MNT/libc"
+TEST_DIFF1_RANGE_FD=$?
+
+compare_sizes "$OUTSIDE" "$MNT/syscall"
+TEST_DIFF2_RANGE_FD=$?
+unset LD_PRELOAD
+# remove costly data
+LD_PRELOAD=$GKFS rm -rf $OUTSIDE
+LD_PRELOAD=$GKFS rm -rf $MNT/libc
+LD_PRELOAD=$GKFS rm -rf $MNT/syscall
+
+
+
+# Stop the daemon
+kill $DAEMON_PID
+
+# Check test success
+if [ $TEST_DIFF1_PROTECT_FD -eq 0 ]; then
+  echo "Data from LIBC Interception (PROTECT_FD) == Original!"
+else
+  echo "Data from LIBC Interception (PROTECT_FD) != Original!"
+fi
+
+if [ $TEST_DIFF2_PROTECT_FD -eq 0 ]; then
+  echo "Data from SYSCALL Interception (PROTECT_FD) == Original!"
+else
+  echo "Data from SYSCALL Interception (PROTECT_FD) != Original!"
+fi
+
+
+# Check test success
+if [ $TEST_DIFF1_RANGE_FD -eq 0 ]; then
+  echo "Data from LIBC Interception (RANGE_FD) == Original!"
+else
+  echo "Data from LIBC Interception (RANGE_FD) != Original!"
+fi
+
+if [ $TEST_DIFF2_RANGE_FD -eq 0 ]; then
+  echo "Data from SYSCALL Interception (RANGE_FD) == Original!"
+else
+  echo "Data from SYSCALL Interception (RANGE_FD) != Original!"
+fi
+
+# Final exit code logic
+if [ $TEST_DIFF1_PROTECT_FD -eq 0 ] && [ $TEST_DIFF2_PROTECT_FD -eq 0 ] && [ $TEST_DIFF1_RANGE_FD -eq 0 ] && [ $TEST_DIFF2_RANGE_FD -eq 0 ]; then
+  exit 0
+else
+  exit 1
+fi
\ No newline at end of file