diff --git a/CHANGES.txt b/CHANGES.txt
index 90e3780..856c7f0 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,8 @@
+v3.5.96
+- Added option to set write_mostly for your internal HDDs so DSM will normally read from your faster internal SSD(s).
+    - It can automatically set DSM to read from your internal SSDs.
+    - Or you can tell the script which internal drive(s) DSM should read from.
+
 v3.5.94
 - Updated to support newer drive db versions.
   - Synology added size_gb in a recent host v7 version (in SynoOfflinePack 764).
diff --git a/README.md b/README.md
index 4a6b63c..7270654 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,9 @@ #### What the script does:
 * Optionally disable DSM's "support_memory_compatibility" to prevent <a href=images/ram_warning.png/>non-Synology memory notifications</a>.
 * Optionally edits max supported memory to match the amount of memory installed, if installed memory is greater than the current max memory setting.
     * DSM only uses the max memory setting when calculating the reserved RAM area size for SSD caches.
+* Optionally set write_mostly for your internal HDDs so DSM will normally read from your faster internal SSD(s).
+    * It can automatically set DSM to read from your internal SSDs.
+    * Or you can tell the script which internal drive(s) DSM should read from.
 * Optionally disables Western Digital Device Analytics (aka WDDA) to prevent DSM showing a [warning for WD drives that are 3 years old](https://arstechnica.com/gadgets/2023/06/clearly-predatory-western-digital-sparks-panic-anger-for-age-shaming-hdds).
     * DSM 7.2.1 already has WDDA disabled.
 * Enables M2D20, M2D18, M2D17 and E10M20-T1 if present on Synology NAS that don't officially support them.
@@ -81,7 +84,16 @@ ### Options when running the script <a name="options"></a>
                           DSM 7.2.1 already has WDDA disabled
   -p, --pcie            Enable creating volumes on M2 in unknown PCIe adaptor
   -e, --email           Disable colored text in output scheduler emails
-      --restore         Undo all changes made by the script
+  -S, --ssd=DRIVE       Enable write_mostly on slow internal drives so DSM 
+                        runs from the fast internal drive(s).
+                          -S automatically sets internal SSDs as DSM default
+                          --ssd=DRIVE requires the fast drive(s) as argument,
+                          or restore as the argument to set drives to default
+                          --ssd=sata1 or --ssd=sata1,sata2 or --ssd=sda etc
+                          --ssd=sata1 or --ssd=sata1,sata2 or --ssd=sda etc
+                          --ssd=restore
+      --restore         Undo all changes made by the script (except -S --ssd)
+       --autoupdate=AGE  Auto update script (useful when script is scheduled)
       --autoupdate=AGE  Auto update script (useful when script is scheduled)
                           AGE is how many days old a release must be before
                           auto-updating. AGE must be a number: 0 or greater
diff --git a/syno_hdd_db.sh b/syno_hdd_db.sh
index 6840261..beb944d 100644
--- a/syno_hdd_db.sh
+++ b/syno_hdd_db.sh
@@ -17,6 +17,10 @@
 # https://smarthdd.com/database/
 
 # RECENT CHANGES
+# Make DSM read md0 and md1 from SSD drive(s) if internal SSD and HDD are installed.
+# https://github.com/007revad/Synology_HDD_db/issues/318
+# https://www.techspark.de/speed-up-synology-dsm-with-hdd-ssd/
+# https://raid.wiki.kernel.org/index.php/Write-mostly
 
 # TODO
 # Enable SMART Attributes button on Storage Manager
@@ -25,7 +29,7 @@
 # /var/packages/StorageManager/target/ui/storage_panel.js
 
 
-scriptver="v3.5.94"
+scriptver="v3.5.96"
 script=Synology_HDD_db
 repo="007revad/Synology_HDD_db"
 scriptname=syno_hdd_db
@@ -38,7 +42,7 @@ if [ ! "$(basename "$BASH")" = bash ]; then
 fi
 
 # Check script is running on a Synology NAS
-if ! /usr/bin/uname -a | grep -i synology >/dev/null; then
+if ! /usr/bin/uname -a | grep -q -i synology; then
     echo "This script is NOT running on a Synology NAS!"
     echo "Copy the script to a folder on the Synology"
     echo "and run it from there."
@@ -69,7 +73,15 @@ Options:
                           DSM 7.2.1 already has WDDA disabled
   -p, --pcie            Enable creating volumes on M2 in unknown PCIe adaptor
   -e, --email           Disable colored text in output scheduler emails
-      --restore         Undo all changes made by the script
+  -S, --ssd=DRIVE       Enable write_mostly on slow internal drives so DSM 
+                        runs from the fast internal drive(s).
+                          -S automatically sets internal SSDs as DSM default
+                          --ssd=DRIVE requires the fast drive(s) as argument,
+                          or restore as the argument to set drives to default
+                          --ssd=sata1 or --ssd=sata1,sata2 or --ssd=sda etc
+                          --ssd=sata1 or --ssd=sata1,sata2 or --ssd=sda etc
+                          --ssd=restore
+      --restore         Undo all changes made by the script (except -S --ssd)
       --autoupdate=AGE  Auto update script (useful when script is scheduled)
                           AGE is how many days old a release must be before
                           auto-updating. AGE must be a number: 0 or greater
@@ -96,12 +108,12 @@ args=("$@")
 
 
 # Check for flags with getopt
-if options="$(getopt -o abcdefghijklmnopqrstuvwxyz0123456789 -l \
-    restore,showedits,noupdate,nodbupdate,m2,force,incompatible,ram,pcie,wdda,email,autoupdate:,help,version,debug \
+if options="$(getopt -o Sabcdefghijklmnopqrstuvwxyz0123456789 -l \
+    ssd:,restore,showedits,noupdate,nodbupdate,m2,force,incompatible,ram,pcie,wdda,email,autoupdate:,help,version,debug \
     -- "$@")"; then
     eval set -- "$options"
     while true; do
-        case "${1,,}" in
+        case "$1" in
             --restore)          # Restore changes from backups
                 restore=yes
                 break
@@ -109,6 +121,20 @@ if options="$(getopt -o abcdefghijklmnopqrstuvwxyz0123456789 -l \
             -s|--showedits)     # Show edits done to host db file
                 showedits=yes
                 ;;
+            -S)                 # Enable writemostly for md0 and md1
+                ssd=yes
+                ;;
+            --ssd)              # Enable writemostly for md0 and md1
+                ssd=yes
+                if [[ ${2,,} == "restore" ]]; then
+                    ssd_restore=yes
+                else
+                    IFS=$','
+                    for d in $2; do ssds_writemostly+=("${d,,}"); done
+                    unset IFS
+                fi
+                shift
+                ;;
             -n|--nodbupdate|--noupdate)  # Disable disk compatibility db updates
                 nodbupdate=yes
                 ;;
@@ -337,7 +363,7 @@ scriptvol=$(echo "$scriptpath" | cut -d"/" -f2)
 vg=$(lvdisplay | grep /volume_"${scriptvol#volume}" | cut -d"/" -f3)
 md=$(pvdisplay | grep -B 1 -E '[ ]'"$vg" | grep /dev/ | cut -d"/" -f3)
 # shellcheck disable=SC2002  # Don't warn about "Useless cat"
-if cat /proc/mdstat | grep "$md" | grep nvme >/dev/null; then
+if cat /proc/mdstat | grep "$md" | grep -q nvme; then
     echo -e "\n${Yellow}WARNING${Off} Don't store this script on an NVMe volume!"
 fi
 
@@ -734,7 +760,7 @@ set_vendor(){
     if [[ $vendor ]]; then
         # DS1817+, DS1517+, RS1219+, RS818+ don't have pci_vendor_ids.conf
         if [[ "$vidfile" ]]; then
-            if ! grep "$vid" "$vidfile" >/dev/null; then
+            if ! grep -q "$vid" "$vidfile"; then
                 /usr/syno/bin/synosetkeyvalue "$vidfile" "${vid,,}" "$vendor"
                 val=$(/usr/syno/bin/synogetkeyvalue "$vidfile" "${vid,,}")
                 if [[ $val == "${vendor}" ]]; then
@@ -743,7 +769,7 @@ set_vendor(){
                     echo -e "\nFailed to add $vendor to pci_vendor_ids!" >&2
                 fi
             fi
-            if ! grep "$vid" "$vidfile2" >/dev/null; then
+            if ! grep -q "$vid" "$vidfile2"; then
                 /usr/syno/bin/synosetkeyvalue "$vidfile2" "${vid,,}" "$vendor"
             fi
 
@@ -751,10 +777,10 @@ set_vendor(){
             if [[ ${#vid} -eq "5" ]]; then
                 vid="0x0${vid: -3}"
             fi
-            if ! grep "$vid" "$vidfile" >/dev/null; then
+            if ! grep -q "$vid" "$vidfile"; then
                 /usr/syno/bin/synosetkeyvalue "$vidfile" "${vid,,}" "$vendor"
             fi
-            if ! grep "$vid" "$vidfile2" >/dev/null; then
+            if ! grep -q "$vid" "$vidfile2"; then
                 /usr/syno/bin/synosetkeyvalue "$vidfile2" "${vid,,}" "$vendor"
             fi
 
@@ -1085,6 +1111,7 @@ else
     echo
 fi
 
+
 #------------------------------------------------------------------------------
 # Check databases and add our drives if needed
 
@@ -1123,10 +1150,10 @@ fi
 getdbtype(){ 
     # Detect drive db type
     # Synology misspelt compatibility as compatbility
-    if grep -F '{"disk_compatbility_info":' "$1" >/dev/null; then
+    if grep -q -F '{"disk_compatbility_info":' "$1"; then
         # DSM 7 drive db files start with {"disk_compatbility_info":
         dbtype=7
-    elif grep -F '{"success":1,"list":[' "$1" >/dev/null; then
+    elif grep -q -F '{"success":1,"list":[' "$1"; then
         # DSM 6 drive db files start with {"success":1,"list":[
         dbtype=6
     else
@@ -1242,7 +1269,7 @@ updatedb(){
 
     if [[ $dbtype -gt "6" ]]; then
         # db type 7 used from DSM 7.1 and later
-        if grep "$hdmodel"'":{"'"$fwrev" "$2" >/dev/null; then
+        if grep -q "$hdmodel"'":{"'"$fwrev" "$2"; then
             echo -e "${Yellow}$hdmodel${Off} already exists in ${Cyan}$(basename -- "$2")${Off}" >&2
         else
             common_string=\"size_gb\":$size_gb,
@@ -1264,13 +1291,13 @@ updatedb(){
             default="$default"}]}}}
 
             # Synology misspelt compatibility as compatbility
-            if grep '"disk_compatbility_info":{}' "$2" >/dev/null; then
+            if grep -q '"disk_compatbility_info":{}' "$2"; then
                 # Replace "disk_compatbility_info":{} with
                 # "disk_compatbility_info":{"WD40PURX-64GVNY0":{"80.00A80":{ ... }}},"default":{ ... }}}}
                 #echo "Edit empty db file:"  # debug
                 editdb7 "empty" "$2"
 
-            elif grep '"'"$hdmodel"'":' "$2" >/dev/null; then
+            elif grep -q '"'"$hdmodel"'":' "$2"; then
                 # Replace "WD40PURX-64GVNY0":{ with "WD40PURX-64GVNY0":{"80.00A80":{ ... }}},
                 #echo "Insert firmware version:"  # debug
                 editdb7 "insert" "$2"
@@ -1283,25 +1310,25 @@ updatedb(){
         fi
 
         # Edit existing drives in db with compatibility:unverified  # Issue #224
-        if grep 'unverified' "$2" >/dev/null; then
+        if grep -q 'unverified' "$2"; then
             sed -i 's/unverified/support/g' "$2"
-            if ! grep 'unverified' "$2" >/dev/null; then
+            if ! grep -q 'unverified' "$2"; then
                 echo -e "Edited unverified drives in ${Cyan}$(basename -- "$2")${Off}" >&2
             fi
         fi
 
         # Edit existing drives in db with compatibility:not_support
         if [[ $incompatible == "yes" ]]; then
-            if grep 'not_support' "$2" >/dev/null; then
+            if grep -q 'not_support' "$2"; then
                 sed -i 's/not_support/support/g' "$2"
-                if ! grep 'not_support' "$2" >/dev/null; then
+                if ! grep -q 'not_support' "$2"; then
                     echo -e "Edited incompatible drives in ${Cyan}$(basename -- "$2")${Off}" >&2
                 fi
             fi
         fi
     elif [[ $dbtype -eq "6" ]]; then
         # db type 6 used up to DSM 7.0.1
-        if grep "$hdmodel" "$2" >/dev/null; then
+        if grep -q "$hdmodel" "$2"; then
             echo -e "${Yellow}$hdmodel${Off} already exists in ${Cyan}$(basename -- "$2")${Off}" >&2
         else
             # example:
@@ -1402,7 +1429,7 @@ enable_card(){
         backupdb "$adapter_cards2" long
 
         # Check if section exists
-        if ! grep '^\['"$2"'\]$' "$1" >/dev/null; then
+        if ! grep -q '^\['"$2"'\]$' "$1"; then
             echo -e "Section [$2] not found in $(basename -- "$1")!" >&2
             return
         fi
@@ -1608,7 +1635,7 @@ edit_modeldtb(){
             # Edit model.dts
             for c in "${cards[@]}"; do
                 # Edit model.dts if needed
-                if ! grep "$c" "$dtb_file" >/dev/null; then
+                if ! grep -q "$c" "$dtb_file"; then
                     dts_m2_card "$c" "$dts_file"
                     echo -e "Added ${Yellow}$c${Off} to ${Cyan}model${hwrev}.dtb${Off}" >&2
                 else
@@ -1663,6 +1690,91 @@ for c in "${m2cards[@]}"; do
 done
 
 
+#------------------------------------------------------------------------------
+# Set or restore writemostly
+
+set_writemostly(){ 
+    # $1 is writemostly or in_sync
+    # $2 is sata1 or sas1 or sda etc
+    if [[ ${1::2} == "sd" ]]; then
+        # sda etc
+        # md0 DSM system partition
+        echo "$1" > /sys/block/md0/md/dev-"${2}"1/state
+        # Show setting
+        echo -n "$2 DSM partition:  "
+        cat /sys/block/md0/md/dev-"${2}"1/state
+
+        # md1 DSM swap partition
+        echo "$1" > /sys/block/md1/md/dev-"${2}"2/state
+        # Show setting
+        echo -n "$2 Swap partition: "
+        cat /sys/block/md1/md/dev-"${2}"2/state
+    else
+        # sata1 or sas1 etc
+        # md0 DSM system partition
+        echo "$1" > /sys/block/md0/md/dev-"${2}"p1/state
+        # Show setting
+        echo -n "$2 DSM partition:  "
+        cat /sys/block/md0/md/dev-"${2}"p1/state
+
+        # md1 DSM swap partition
+        echo "$1" > /sys/block/md1/md/dev-"${2}"p2/state
+        # Show setting
+        echo -n "$2 Swap partition: "
+        cat /sys/block/md1/md/dev-"${2}"p2/state
+    fi
+}
+
+if [[ $ssd == "yes" ]]; then
+    # Get array of internal drives
+    readarray -t internal_drives < <(synodisk --enum -t internal | grep 'Disk path' | cut -d"/" -f3)
+
+    if [[ $ssd_restore == "yes" ]]; then
+        # Restore all internal drives to just in_sync
+        echo -e "\nRestoring internal drive's state:"
+        for idrive in "${internal_drives[@]}"; do
+            #if ! grep -q "write_mostly"; then 
+                set_writemostly -writemostly "$idrive"
+            #fi
+        done
+
+    elif [[ ${#ssds_writemostly[@]} -gt "0" ]]; then
+        # User specified their fast drive(s)
+        echo -e "\nSetting slow internal HDDs state to write_mostly:"
+        for idrive in "${internal_drives[@]}"; do
+            if [[ ! ${ssds_writemostly[*]} =~ $idrive ]]; then
+                set_writemostly writemostly "$idrive"
+            fi
+        done
+
+    else
+        # Get list of internal HDDs and qty of SSDs
+        internal_ssd_qty="0"
+        for idrive in "${internal_drives[@]}"; do
+            internal_drive="$(echo "$idrive" | awk '{printf $4}')"
+            if synodisk --isssd "$internal_drive" >/dev/null; then
+                # exit code 0 = is not SSD
+                # exit code 1 = is SSD
+
+                # Add internal HDDs to array
+                internal_hdds+=("$internal_drive")
+            else
+                # Count number of internal 2.5 inch SSDs
+                internal_ssd_qty=$((internal_ssd_qty +1))
+            fi
+        done
+
+        # Set HDDs to writemostly if there's also internal SSDs
+        if [[ $internal_ssd_qty -gt "0" ]] && [[ ${#internal_hdds[@]} -gt "0" ]]; then
+            # There are internal SSDs and HDDs
+            echo -e "\nSetting internal HDDs state to write_mostly:"
+            for idrive in "${internal_hdds[@]}"; do
+                set_writemostly writemostly "$idrive"
+            done
+        fi
+    fi
+fi
+
 
 #------------------------------------------------------------------------------
 # Edit /etc.defaults/synoinfo.conf
@@ -1836,7 +1948,7 @@ fi
 
 # Enable nvme support
 # shellcheck disable=SC2010  # Don't warn about "Don't use ls | grep"
-if ls /dev | grep nvme >/dev/null ; then
+if ls /dev | grep -q nvme; then
     if [[ $m2 != "no" ]]; then
         # Check if nvme support is enabled
         setting="$(/usr/syno/bin/synogetkeyvalue $synoinfo supportnvme)"
@@ -1868,7 +1980,7 @@ fi
 
 # Enable m2 volume support
 # shellcheck disable=SC2010  # Don't warn about "Don't use ls | grep"
-if ls /dev | grep "nv[em]" >/dev/null ; then
+if ls /dev | grep -q "nv[em]"; then
     if [[ $m2 != "no" ]]; then
         if [[ $m2exists == "yes" ]]; then
             # Check if m2 volume support is enabled
@@ -1971,7 +2083,7 @@ if [[ -f "$strgmgr" ]] && [[ $buildnumber -gt 42962 ]]; then
     # DSM 7.2 and later
     if [[ ${#m2cards[@]} -gt "0" ]] || [[ $forcepci == "yes" ]]; then
 
-        if grep 'notSupportM2Pool_addOnCard' "$strgmgr" >/dev/null; then
+        if grep -q 'notSupportM2Pool_addOnCard' "$strgmgr"; then
             # Backup storage_panel.js"
 
             if [[ $buildnumber -gt 64570 ]]; then
@@ -1994,7 +2106,7 @@ if [[ -f "$strgmgr" ]] && [[ $buildnumber -gt 42962 ]]; then
             sed -i 's/notSupportM2Pool_addOnCard:this.T("disk_info","disk_reason_m2_add_on_card"),//g' "$strgmgr"
             sed -i 's/},{isConditionInvalid:0<this.pciSlot,invalidReason:"notSupportM2Pool_addOnCard"//g' "$strgmgr"
             # Check if we edited file
-            if ! grep 'notSupportM2Pool_addOnCard' "$strgmgr" >/dev/null; then
+            if ! grep -q 'notSupportM2Pool_addOnCard' "$strgmgr"; then
                 echo -e "Enabled creating pool on drives in M.2 adaptor card."
             else
                 echo -e "${Error}ERROR${Off} Failed to enable creating pool on drives in M.2 adaptor card!"
@@ -2052,3 +2164,4 @@ if [[ $dsm -eq "6" ]] || [[ $rebootmsg == "yes" ]]; then
 fi
 
 exit
+