Enables sequential I/O for your SSD caches, like DSM 6 had when you unticked the "Skip sequential I/O" option.

Note: Monitor your NVMe drive and 10G card temperature. There have been reports online that enabling sequential I/O for an SSD cache can cause a 10G network card to overheat (which may be why Synology disabled SSD cache sequential I/O from DSM 7 onwards). It will also wear out the NVMe drive(s) much faster.

1. Download the latest version Source code (zip) from https://github.com/007revad/Synology_enable_sequential_IO/releases
2. Save the download zip file to a folder on the Synology.
3. Unzip the zip file.

How to enable SSH and login to DSM via SSH

Note: Replace /volume1/scripts/ with the path to where the script is located. Run the script then reboot the Synology:

sudo -i /volume1/scripts/syno_seq_io.sh

To ensure that your cache(s) still have sequential I/O enabled after a reboot you should schedule the script to run at boot.

See How to schedule a script to run at boot in Synology Task Scheduler

      --volumes=VOLUME  Volume or volumes to enable sequential I/O for
                          Use when scheduling the script
                          Examples:
                          --volumes=volume_1
                          --volumes=volume_1,volume_3,volume_4
      --kb=KB           Set a specific sequential I/O kb value
                          Use to disable sequential I/O
                          --kb=1024
  -e, --email           Disable colored text in output scheduler emails
  -h, --help            Show this help message
  -v, --version         Show the script version

You can run this script with a parameter to specify the skip_seq_thresh_kb

For example the following would set the cache you select back to default

sudo -i /volume1/scripts/syno_seq_io.sh 1024

Note: If no parameter the script defaults to 0 (which enables sequential I/O).

Enabling sequential I/O

Reset a cache to 1024 KB to disable sequential I/O

Scheduled to enable sequential I/O for 2 caches with --volume option

Choose from multiple caches