diff --git a/.github/workflows/c2v_ci.yml b/.github/workflows/c2v_ci.yml
index 7667c3645f..610224a981 100644
--- a/.github/workflows/c2v_ci.yml
+++ b/.github/workflows/c2v_ci.yml
@@ -28,16 +28,12 @@ concurrency:
 
 jobs:
   build-doom:
-    strategy:
-      matrix:
-        os: [ubuntu-20.04]
-      fail-fast: false
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-24.04
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4
       - name: Build V
-        run: make -j4 && ./v symlink
+        run: make && ./v symlink
 
       - name: Set 8.8.8.8 as dns server
         run: |
@@ -81,7 +77,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Build V
-        run: make -j4 && ./v symlink
+        run: make && ./v symlink
 
       - name: Set 8.8.8.8 as dns server
         run: |
diff --git a/.github/workflows/native_backend_ci.yml b/.github/workflows/native_backend_ci.yml
index e03ea562d4..eaa7be0bc6 100644
--- a/.github/workflows/native_backend_ci.yml
+++ b/.github/workflows/native_backend_ci.yml
@@ -52,7 +52,7 @@ jobs:
   native-backend:
     strategy:
       matrix:
-        os: [ubuntu-20.04, windows-2019]
+        os: [ubuntu-24.04, windows-2019]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
diff --git a/.github/workflows/release_ci.yml b/.github/workflows/release_ci.yml
index 73617deef6..f582015507 100644
--- a/.github/workflows/release_ci.yml
+++ b/.github/workflows/release_ci.yml
@@ -24,11 +24,11 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-13, macos-14, windows-latest]
+        os: [ubuntu-22.04, macos-13, macos-14, windows-latest]
         include:
-          - os: ubuntu-20.04
+          - os: ubuntu-22.04
             cc: gcc
-          - os: ubuntu-20.04
+          - os: ubuntu-22.04
             target: linux
             artifact: v_linux.zip
           - os: macos-13
diff --git a/.github/workflows/symlink_ci.yml b/.github/workflows/symlink_ci.yml
index 9198b216f7..54030f5d5f 100644
--- a/.github/workflows/symlink_ci.yml
+++ b/.github/workflows/symlink_ci.yml
@@ -20,7 +20,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-13]
+        os: [ubuntu-24.04, macos-13]
       fail-fast: false
     steps:
       - uses: actions/checkout@v4
diff --git a/.github/workflows/v_apps_and_modules_compile_ci.yml b/.github/workflows/v_apps_and_modules_compile_ci.yml
index f8c069794e..da2670d670 100644
--- a/.github/workflows/v_apps_and_modules_compile_ci.yml
+++ b/.github/workflows/v_apps_and_modules_compile_ci.yml
@@ -223,7 +223,7 @@ jobs:
   vpm-site-compile:
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-14]
+        os: [ubuntu-24.04, macos-14]
       fail-fast: false
     runs-on: ${{ matrix.os }}
     steps:
diff --git a/.github/workflows/vsl_and_vtl_compile_ci.yml b/.github/workflows/vsl_and_vtl_compile_ci.yml
index da817e8f32..506832bd32 100644
--- a/.github/workflows/vsl_and_vtl_compile_ci.yml
+++ b/.github/workflows/vsl_and_vtl_compile_ci.yml
@@ -24,7 +24,7 @@ jobs:
   vsl-compiles:
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-14]
+        os: [ubuntu-24.04, macos-14]
       fail-fast: false
     runs-on: ${{ matrix.os }}
     timeout-minutes: 15
@@ -41,7 +41,7 @@ jobs:
           v retry -- sudo apt -qq update
           v retry -- sudo apt -qq install \
             libgc-dev libgl1-mesa-dev mesa-common-dev liblapacke-dev libopenblas-dev libopenmpi-dev \
-            opencl-headers libxcursor-dev libxi-dev libxrandr-dev libhdf5-cpp-103 libhdf5-dev libhdf5-mpi-dev hdf5-tools
+            opencl-headers libxcursor-dev libxi-dev libxrandr-dev libhdf5-cpp-103-1t64 libhdf5-dev libhdf5-mpi-dev hdf5-tools
           else
             v retry brew install coreutils hdf5 open-mpi openblas lapack opencl-headers
           fi
@@ -55,7 +55,7 @@ jobs:
   vtl-compiles:
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-14]
+        os: [ubuntu-24.04, macos-14]
       fail-fast: false
     runs-on: ${{ matrix.os }}
     timeout-minutes: 15