The Continuing Need for Centralized Local Storage

It is amazing how much data our family generates. We record our home videos in 4K resolution. We have scanned over 100 years of our family photo albums and slides in TIFF format for permanent archival. I shoot high-resolution images on my Nikon D500 and Fuji X100F cameras in RAW format. I ripped hundreds of CDs that I bought over the decades in lossless audio format. We have constructed a multi-room DVR solution for our home, time-shifting cable and local OTA content. I run my application development environments in virtual machines. And, we back up all of our Macs using our NAS’ Time Capsule service.

All of this requires many more terabytes of real-time storage than is cost-effective or feasible with current broadband connections and cloud storage plans. Even when multi-terabyte cloud storage and broadband connectivity becomes more practical for consumers, I would still want local storage for data redundancy and disaster recovery.

Devices that create, consume, and edit this content are proliferating in our family: iMacs, Macbooks, iPads, and iPhones. Yet, even those devices that contain the most storage fall short of our needs. My new iMac required a special order just for a 3TB hard drive (incredibly, the default is only a 1TB HD)! My new Macbook has a mere 512GB of SSD storage.

I have owned network attached storage (NAS) devices for over 10 years. Netgear’s ReadyNAS was one of the first affordable devices. I bought two generations of their ReadyNAS boxes. Later, I purchased Synology’s DS1812+ and DS1815+ NAS devices.

Now, I have upgraded to the Synology DS1817+. Synology’s higher-end NAS devices have always been well received. The DS1817+ is Small Net Builder’s highest rated NAS.

Hardware Capabilities

Technical Specifications

The DS1817+ is an eight drive bay, RAID 5-class NAS. It is built on a quad-core, 64-bit 2.4 GHz Intel Atom C2538 platform with an AES-NI hardware encryption engine. There are two memory configurations available: 2GB (1 x 2GB) and 8GB (2 x 4GB). I selected the 8GB version but you can easily buy the 2GB version and add memory later. The DS1817+ is expandable to 16 GB (8 GB x 2) though I doubt that much memory is necessary for traditional file serving functionality.

It is possible to increase the storage to up to 18 drives using two DX517 expansion units. However, I recommend purchasing a second DS1817+ over purchasing DX517 expansion units due to the marginal cost and disaster recovery benefits.

The DS1517+ is similar in hardware design but only has five drive bays. I recommend buying the eight-bay DS1817+ over the DS1517+ because you will automatically lose two drives’ storage for SHR2 RAID. Further, if you wish to use both SSD cache and 10Gbps Ethernet, then you will need to use a third drive bay for the SSD storage.

That said, there’s no need to immediately buy more than three hard drives if you don’t need more storage than the first hard drive. Synology makes it easy to add new hard drives to your NAS and easily expand your storage volume. This saves you the upfront cost of purchasing up to eight hard drives.

The DS1817+ boasts 4x RJ-45 1GbE LAN ports with link aggregation and failover support. It also includes 4x USB 3.0 ports and 2x eSATA ports.

PCIe Expansion Card

New for the DS1x17+ series is a PCIe expansion Gen2 x8 card slot (x4 link). This is intended for either a dual M.2 SSD adapter card for SSD cache or a 10Gbps PCIe network interface card. For home users, I believe that an SSD cache is more valuable than a 10Gbps NIC card. Our home is wired throughout with Gigabit Ethernet and has Ubiquiti Unifi managed sewitcheds and multiple Wireless-AC access points. None of these can leverage the full speed of 10Gbps. Consumers with heavy data traffic like multi-room DVR would be better served in the near term using the DS1817’s Ethernet ports in link aggregation because this is backwards compatible. In theory, up to four Ethernet ports could be bonded together for up to 4 Gps.

Currently, the DS1817+ only supports Synology’s M2D17 expansion card even if you use a compatible M.2 SATA SSD. Initially, I purchased the (much cheaper) Asus HYPER M.2 X4 adapter card and a 275GB Crucial M.2 SSD for a simple read cache. Unfortunately, Synology didn’t detect the Asus HYPER M.2 X4 card. So, I purchased the M2D17 expansion card and a second 275GB Crucial M.2 SSD. Then, I created a read-write cache in Storage Manager. For SSD cache configuration and performance benchmarks, I recommend this excellent article. Here are their findings:

“When SSD read-write cache is enabled, we observed great reduction in terms of read and write latencies. There is approximately 280% to 400% reduction in reading and writing latencies. Similarly, stark improvement in both throughput and IOPS were also observed. Input/ Output per second (IOPS) also improved as much as 400%.”

If you are going to invest in the hardware for a SSD read-write cache, then I also recommend configuring  at least two of the Ethernet ports in link aggregation mode, assuming that you have a managed network switch. This will ensure that your Gigabit Ethernet port does not become a bottleneck.

Software Features

As good as Synology’s hardware is, its operating system, DiskStation Manager, is even better. Synology DSM 6.2 provides a complete HTML-based, drag-and-drop windowing environment to manage files, applications, and services. Many of the more advanced services are simplified with wizards that walk users through service creation, configuration, and updates. Synology offers an online demo of DSM 6.2 here.

Since this article is written from a prosumer perspective, I won’t go into too much detail about all the small enterprise capabilities that the Synology DSM OS offers. Key enterprise features include using it as an Active Directory Server, a Windows Offloaded Data Transfer server, a Synology video surveillance server, or a server for Synology productivity and collaboration applications. There are a variety of LAMP-based packages that you can install such as WordPress, Drupal, MariaDB, and email servers. Your Synology NAS can act as a server for Docker containers, OpenStack Cinder, and VMware vSphere 6 VM’s. You can even run two Synology NAS units in high availability mode. My point is that the Synology hardware and software platform is far more sophisticated than the typical consumer expects, all for the price of a PC.

File System

For internal storage, the DS1817+ supports both Btrfs and EXT4 file systems. I used EXT4 for many years because it was a seamless evolution of Linux’s historic EXT3 file system. EXT4 on SHR2 RAID could safely suffer the simultaneous loss of up to two hard drives without data loss.

Now, Btrfs is mature enough that I recommend it over EXT4. Btrfs on SHR2 RAID goes beyond drive failure, solving the problem of “bit rot”. On EXT4 (and many other file systems), it is possible for data to silently corrupt due to issues on the hard drive (e.g. such as bad sectors) short of total drive failure. Btrfs supports automatic file and folder self-healing, auto-defragmentation, snapshot replication, and instant file cloning for SMB.

Unfortunately, it is not possible to migrate from EXT4 to Btrfs on Synology. Therefore, I completely rebuilt the volume when I upgraded to the Synology DS1817+. I highly recommend Synology’s File Sync feature to perform this migration. This is a GUI front end to rsync that also automatically creates new file shares on the target Synology NAS.

File Sharing, Synchronization & Backup

The primary function of a NAS unit is file sharing and synchronization. Synology DSM supports a variety of file sharing protocols including: SMB, AFP, NFS, FTP, WebDAV, SFTP, FTPS and rsync. For security and overhead reasons, I recommend enabling only those protocols that you will regularly use. For me, that is SMBv2+ and SSH/SFTP.

• Since Apple has now switched from AFP to SMBX, there is no need to enable AFP anymore. This is true even if, like me, you use your NAS for Time Capsule functionality because Apple now supports Time Capsule over SMB. However, I have experienced volume unmount issues with High Sierra.
• You need to enable SMBv2 for Mac compatibility. I recommend SMBv2 as your minimum SMB version due to recent exploits associated with the decades-old SMBv1 protocol. Additionally, SMBv2 and later are faster and less complex protocols.
• If you use Photon or Kodi, then you need to enable a compatible file sharing protocol. Photon and Kodi supports SMBv3. So you should use that, disabling SMBv1. Since only SMBv1 is supported on Kodi 18 Android, AFP is deprecated, and NFS is fast but insecure (no username or password is required), I recommend using WebDAV for media streaming with Kodi.

Frequent, versioned backups on devices on your home network is an essential part of network security. Macs can use the DS1817+ for encrypted Time Machine backups, which is even more valuable now that Apple has discontinued the Time Capsule. For PCs on your home network, you can create up to 32 versions of files on your PC. Like Time Machine for Macs, this permits you to restore deleted or corrupted files on your Macs and PCs from your Synology NAS using CloudStation.1

It is also possible to back up your Synology NAS to a second onsite Synology NAS or to sync data on your NAS to the cloud. Leveraging Btrfs, Synology NAS can replicate data from your DS1817+ to Amazon Drive, Dropbox, Google Drive, Google Cloud Storage, Microsoft OneDrive, and OpenStack Swift compatible cloud services.23

Security

DSM 6.2 provides an advanced firewall, intrusion prevention, antivirus capabilities, shared folder encryption, two-step verification (two-factor authentication), account protection (account and IP address blocking after multiple failed attempts), multiple SSL certificates, and Let’s Encrypt integration. I recommend enabling all of these security features.

I also advise:

• Keeping your firmware up-to-date
• Regularly scanning your files using the included antivirus program
• Disabling remote access to your NAS
• Blocking Internet access to your NAS
• Running the minimal number of services on your NAS and virtualizing those services where possible

Applications

Synology

• Synology has a number of consumer-oriented multimedia applications including VideoStation, AudioStation, PhotoStation, iTunes Server, and Media (DLNA) Server. VideoStation and AudioStation increasingly are solid competitors to Plex and Emby for your home theater library. Each of these Synology server apps has a companion mobile app for media playback.
• If you are uncomfortable with third party cloud services, it is possible to use your Synology NAS as your own cloud server, though this means exposing your NAS to the Internet.

Third Party

• Plex Media Server: is a comprehensive home theater application. The DS1817+ is capable enough to do video transcoding to low-end video players though I prefer to use more powerful settop boxes like the Nvidia Shield Android TV.
• Emby Media Server: if you prefer Emby for your media library, it is also available.
• HDHomeRun DVR: although Silicon Dust hasn’t made their DVR available as a Synology package yet, it is possible to install the server on the DS1817+.

Tips

• I always buy my hard drives separate from the Synology chassis. This permits me to buy the hard drive capacity that I need at the lowest possible cost.
• If you own an existing Synology device of equal or lower storage capacity, Synology makes it extraordinarily easy to migrate your data. You simply unplug your drives from your old chassis (like my DS1812 or DS1815) and plug them into the new chassis. The Synology DSM OS will then prompt you to complete the drive migration. Synology NAS devices hold their value on eBay over several years. So this makes it both cost-effective and straightforward to upgrade your NAS every 2-3 years.
• I recommend using Western Digital Red or Gold hard drives for home use. SMB deployments may prefer a faster speed drive like Seagate’s IronWolf series, which also has integrated IronWolf Health Management with DSM 6.1.4 However, I prefer an SSD read-write cache.
• Always enable two-factor authentication. Yes, even on your home network.
• If you have Ubiquiti Unifi managed network switch and wish to use link aggregation mode with your Synology DS1817+, you should configure it as follows:
  1. On the Synology, in Control Panel > Network > Create Bond, select IEEE 802.3ad Dynamic Link Aggregation: This mode optimizes the network traffic received and sent by your Synology NAS, and requires IEEE 802.3ad (Dynamic) Link Aggregation (LACP, 802.1AX) to be enabled on the switch(es).”
  2. In Unifi, select two or more adjacent Ethernet ports, then under Profile Overrides select Operation > Aggregate and Link Negotiation = Auto.
     

Resources

• Synology has a good whitepaper on SSD caching here.
• There is also a useful whitepaper on cloud sync here.
• The latest Synology firmware for the DS1817+ can be downloaded here.
• The user manual for the DS1817+ can be downloaded here.

Updated on April 11th, 2018