diff --git a/deploy.sh b/deploy.sh
index 381c92a..273666d 100644
--- a/deploy.sh
+++ b/deploy.sh
@@ -169,6 +169,7 @@ DISK_TYPE=()
 DISK_HEALTH=()
 DISK_ID=()
 DISK_SIZE=()
+DISK_SIZE_BYTES=()
 
 for DISK in \$(lsblk -x SIZE -d -n -e 7,11 -o NAME); do
   # Disk name and simple path
@@ -193,6 +194,7 @@ for DISK in \$(lsblk -x SIZE -d -n -e 7,11 -o NAME); do
   DISK_ID+=("\$(ls -l /dev/disk/by-id | grep -m1 "../../\$DISK" | awk '{print "/dev/disk/by-id/" \$9}')")
   # Disk size
   DISK_SIZE+=("\$(lsblk -x SIZE -d -n -e 7,11 -o SIZE /dev/\$DISK)")
+  DISK_SIZE_BYTES+=("\$(lsblk -x SIZE -d -n -e 7,11 -b -o SIZE /dev/\$DISK)")
 done
 
 echo "# Hardware detection results on \$(date)" > "${TMPFILE}"
@@ -215,7 +217,8 @@ for var in \
   DISK_TYPE \
   DISK_HEALTH \
   DISK_ID \
-  DISK_SIZE; do
+  DISK_SIZE \
+  DISK_SIZE_BYTES; do
   declare -p \${var} | sed 's/^declare /declare -g /' >> "${TMPFILE}"
 done
 SSHEND
@@ -485,6 +488,25 @@ disks_generation() {
   elif [[ "$CONTENT_DISK_NUMBER" -eq 1 && "$PARITY_DISK_NUMBER" -eq 1 ]]; then
     export CONTENT_DISK_ID="${DATA_DISKS_ID[0]}"
     export PARITY_DISK_ID="${DATA_DISKS_ID[1]}"
+
+    # Calculate partition size to avoid mdadm size mismatch warning
+    local SIZE1=0
+    local SIZE2=0
+    for k in "${!DISK_ID[@]}"; do
+      [[ "${DISK_ID[$k]}" == "$CONTENT_DISK_ID" ]] && SIZE1="${DISK_SIZE_BYTES[$k]}"
+      [[ "${DISK_ID[$k]}" == "$PARITY_DISK_ID" ]] && SIZE2="${DISK_SIZE_BYTES[$k]}"
+    done
+    # Fallback to devpath if ID lookup failed
+    if [[ "$SIZE1" == "0" ]]; then for k in "${!DISK_DEVPATH[@]}"; do [[ "${DISK_DEVPATH[$k]}" == "$CONTENT_DISK_ID" ]] && SIZE1="${DISK_SIZE_BYTES[$k]}"; done; fi
+    if [[ "$SIZE2" == "0" ]]; then for k in "${!DISK_DEVPATH[@]}"; do [[ "${DISK_DEVPATH[$k]}" == "$PARITY_DISK_ID" ]] && SIZE2="${DISK_SIZE_BYTES[$k]}"; done; fi
+
+    local MIN_SIZE=$SIZE1
+    if [[ "$SIZE2" -lt "$SIZE1" ]]; then MIN_SIZE=$SIZE2; fi
+
+    # Subtract 2GB for safety (headers, rounding)
+    local PART_SIZE_GIB=$(( (MIN_SIZE - 2147483648) / 1024 / 1024 / 1024 ))
+    export PARTITION_SIZE="${PART_SIZE_GIB}GiB"
+
     (envsubst < "templates/nix-config/disks/mirror.nix") >> final-nix-config/etc/nixos/disks/disko.nix
 
   # SnapRAID configuration
diff --git a/templates/nix-config/disks/mirror.nix b/templates/nix-config/disks/mirror.nix
index 32657a7..5eb58fa 100644
--- a/templates/nix-config/disks/mirror.nix
+++ b/templates/nix-config/disks/mirror.nix
@@ -6,7 +6,7 @@
           type = "gpt";
           partitions = {
             "data-1" = {
-              size = "100%";
+              size = "$PARTITION_SIZE";
               content = {
                 type = "luks";
                 name = "crypted-content-1";
@@ -27,7 +27,7 @@
           type = "gpt";
           partitions = {
             "parity-1" = {
-              size = "100%";
+              size = "$PARTITION_SIZE";
               content = {
                 type = "luks";
                 name = "crypted-parity-1";
@@ -48,6 +48,7 @@
       "data-storage" = {
         type = "mdadm";
         level = 1;
+        postCreateHook = "mdadm --grow /dev/md/data-storage --bitmap=internal";
         content = {
           type = "filesystem";
           format = "xfs";