When Synology released DS918, many customer (include me) think the additional NVME slots can use as storage. But the truth is - NVME SSD can only setup as cache in DSM.
As DSM is a Linux based system, I think I can try to use command (instead of DSM interface) setup NVME as storage. After some trial and test, I found the step to make it work.
[You should have some knowledge on using command line (ssh) in DSM and highly recommend to backup you system beforehand. Also, you may risk to lost your DSM setting/volume/data.]
Install NVME SSD to DS918 and bootup. Enable SSH login on your DS918 (Control Pannel->Terminal->Enable SSH) if you have not do it before.
Login as root with SSH (I use putty in Windows) and type :
You will see the /dev/nvme0n1 or /dev/nvme1n1 depend on which slot you install the SSD.
fdisk -l /dev/nvme0n1
You wil see the disk information. ( if your SSD at slot 2, use /dev/nvme1n1 instead)
Disk /dev/nvme0n1: 238.5 GiB, 256060514304 bytes, 500118192 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes
Now, create partition. Type:
synopartition --part /dev/nvme0n1 12
and answer 'Y' if you confirm
Device Sectors (Version8: SupportRaid) /dev/nvme0n11 4980480 (2431 MB) /dev/nvme0n12 4194304 (2048 MB) Reserved size: 260352 ( 127 MB) Primary data partition will be created. WARNING: This action will erase all data on '/dev/nvme0n1' and repart it, are you sure to continue? [y/N]y Cleaning all partitions... Creating sys partitions... Creating primary data partition... Please remember to mdadm and mkfs new partitions.
it will create the partition that follow DSM required layout.
fdisk -l /dev/nvme0n1
You will see the partition layout is created
Disk /dev/nvme0n1: 238.5 GiB, 256060514304 bytes, 500118192 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0xef61a3e4 Device Boot Start End Sectors Size Id Type /dev/nvme0n1p1 2048 4982527 4980480 2.4G fd Linux raid autodetect /dev/nvme0n1p2 4982528 9176831 4194304 2G fd Linux raid autodetect /dev/nvme0n1p3 9437184 500103449 490666266 234G fd Linux raid autodetect
Create Basic Disk
I have only tried to create Basic Disk Volume as I have only one SSD. For other type of volume/storage pool (RAID0, RAID1, SHR) , I have not tested.
For Basic Disk, it need to create a single partition RAID1 device in order for DSM to recognize it. (as this is what DSM Storage Manager will do when create a Basic Disk Volume)
To see your current RAID setup
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] md2 : active raid1 sda3 sdb3 5855700544 blocks super 1.2 [2/2] [UU] md3 : active raid1 sdc3 sdd3 9761614848 blocks super 1.2 [2/2] [UU] md1 : active raid1 sda2 sdb2 sdc2 sdd2 2097088 blocks [4/4] [UUUU] md0 : active raid1 sda1 sdb1 sdc1 sdd1 2489920 blocks [4/4] [UUUU]
AFAIK, md0 is system partition and md1 is system swap. You current volume/storage pool will start at md2.
To current your NVME Basic disk, type:
mdadm --create /dev/md4 --level=1 --raid-devices=1 --force /dev/nvme0n1p3
(if md4 already exist, you should use next md number)
And answer y
mdadm: Note: this array has metadata at the start and may not be suitable as a boot device. If you plan to store '/boot' on this device please ensure that your boot-loader understands md/v1.x metadata, or use --metadata=0.90 Continue creating array? y mdadm: Defaulting to version 1.2 metadata mdadm: array /dev/md5 started.
mkfs.ext4 -F /dev/md5
as I use ext4
mke2fs 1.42.6 (21-Sep-2012) Filesystem label=1.42.6-23824 OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 15335424 inodes, 61333024 blocks 25600 blocks (0.04%) reserved for the super user First data block=0 Maximum filesystem blocks=2210398208 1872 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872 Allocating group tables: done Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done
if need btrfs, type
mkfs.btrfs -f /dev/md5
which can use for vm storage
After format complete , type
and after the machine bootup, you will see the Volume in DSM Storage Manager
and the Volume is ready for use.
Test on DSM 6.2.1-23824 Update 1
and after update the DSM to DSM 6.2.1-23824 Update 2 , it still work.
After 7 months with different version of update (last to 6.2.2-24922), it still work without any lost.