I had explored several on-line options like:

1. Amazon Cloud Drive, which is now quite expensive when you send it several tera-bytes.
2. OVH Cloud Archive, that I failed to configure (even with the help of the OVH excellent support team); I had to look at OVH Cloud which is actually priced very similarly to ACD (the price structure is a bit complex, though probably a bit cheaper in the long run).
3. Hubic, which decided to close its doors to new customers.

So, the only solution left was elsewhere: Archiving to an external USB hard drive, but alternating between two physical disks to allow always keeping one off-site (far from fire and flood).

The configuration is not very complicated but requires a bit of attention and of patience.

Pre-requisites  on Synology DSM

The main advantage of Synology is their comprehensive interface very consistent from one NAS model to another (DSM). So, this will essentially apply to all Synology configurations, large or small.

The general idea is to backup one directory from the Synology server to the USB3 external drive. You need the “Hyper Backup” package installed. It is perfectly apt to backups toward a variety of options (I previously used it with Amazon Drive (now too expensive to my taste) and with the now-dead hubiC).

A simple recommendation: Don’t apply versionning on the NAS itself (it tends to eat a ton of space up and appears difficult/impossible reconfigure later on). On the other hand, you can ask that from Hyper Backup which does it perfectly well. Eat space on low cost external storage rather than on high-cost primary storage.

Configuration

Format the hard disk drive(s)

I have chosen 8 tera-byte disks from Seagate. At first, I was looking at the unusual (but cheap) Seagate Archive 8TB. but they have now been replaced with Seagate Barracuda 8TB 5400rpm (which have about the same read speed but a much better write speed, for a similar cost).

Let’s start with connecting the hard drive (in its USB3 enclosure which has been selected as UASP-capable for best performance) to the Synology. It will be immediately recognized and mounted by DSM as USB Disk 1 (or USB Disk 2, depending on the USB port you used). It is highly recommended to format it with a single EXT4 partition.

In the DSM Configuration Panel, under the “External Devices” category, you will select the USB Disk 1 and click on the “Format” button. then, chose the default options.

Progress will be slow (half an hour is usual) but with no special issue to expect.

Name the hard disk drive

This is not very critical, but much more comfortable to name the disk (Data1 and Data2, if you want; For me, it will be Sciurus vulgaris 1 and 2).

Just after formatting, in the DSM Configuration Panel, under “Shared Folder”, select the usb_share_1 directory (the number may vary), then click on the “Edit” button to access a few options including disk naming.

I recommend (your choice) some options:

1. Hide the directory in “Network locations” and “Hide sub-directories” to limit the attack surface of a potential intruder.
2. Encryption: It may come later.
3. Access control: Limit it to the only user which is running Hyper Backup (Nobody else is supposed to directly access your archive).

Configuration of Synology HyperBackup

As I decided to use HyperBackup, everything will be quite simple from this point. In HyperBackup, click on  +, then “Data backup task”.

You will need to designate a backup on an external drive with “Local folder & USB” in the dialog window shown here.

You will then need to describe your backup(s) from several dialogs that are more or less explicit. First, you must point to the destination (the external USB disk):

Then, you will be invited to point to the directory (possibly several of them) that will be backed up. Then,  HyperBackup may offer to backup the parameters from some of the applications you installed on your Synology NAS (I chose not to do this, but it’s really your choice), before arriving to the main settings dialog:

The most critical is certainly client-side encryption (at the bottom of the dialog) which will allow password-protecting the backup data set. As we are intending to leave the external USB disks on a distant shelf, I strongly recommend to protect it against prying eyes. But, be sure not to forget the password, of course…

Then, you will have the opportunity to set the versioning parameters (to be able to travel back in time in your backups to recover one of the successive version backups of a given file). I chose the SmartRecycle parameter with 64 versions (nine months of protection if I apply a daily backup). But you may want to experiment a little in order to make your own decision.

Don’t forger to do this twice: One task per hard disk drive will allow HyperBackup to keep backing up when disks move out or come back from cold storage, depending on which is stored away (each month, maybe).

Finally…

Never forget that a backup only works if you can use its restore feature. It is best to spend a few hours every 6 months to restore a few files and check that everything is still working.

Of course, the best is to test the whole installation in the first hours after setting it up (at least, if you want to write down the restore procedure; You may need it some time in the future…)

• hubiC (from OVH) seems to be fairly good interms of price. But I have to investigate. Right now, I started using the 25GB free acount to test it.

Let me know if you have ideas I can add here.

I am using an optical fiber connection (actually limiteless here) and I synchronize from a Synology DS413j which is defintely weak in CPU (a mono-core ARM). This is probably understating the actual maximum capacity of ACD. Nevertheless, I ran around 60 GB per day for several days. This can be judged on a few hundreds of giga-bytes:

Complement:

The actual transfer speed fluctuated (I was using the server in real production during the initial synchronisation, by adding and moving many files around). The most interesting is that a parameter actuall influenced the overall rate: The number of simultaneous threads/files simultaneously synchronised (no surprise here). The initial value of 3 was nearly immediately upgraded to 6 files and the rate quickly stabilized around 60 GB/day. When I climbed to 9 simultaneous files, the rate went nearly up to 90 GB/day (a little before the yellow curve stops). But moving up to 12 files did not bring any additional gain (out of the graph). You may have to experiment to find your own value (probably depending on the CPU of your Synology server and the possible limitations of your link to ACD).

1. Backups
2. Synchronization between several machines (several PC and several iPhone)

CrashPlan easily provided the backup feature despite a high volume of photo files (more than 2 TB as of today), but was relatively poor interms of synchronization. So, it was time to spend some energy defining the whole need/specification and finding a true solution.

Specification

For backup, my requirements have long been defined:

1. At least three backup copies
2. At least two different technologies (e.g; not to rely only on optical drives or hard drives)
3. At least one off-site location (to be protected against theft, fire hazards, etc., think off-site, or cloud, or external/bank safe box)

For synchronization, previous use of DropBox and Evernote (on small volumes) allowed me to confirm the precise needs I had:

1. Real-time sharing of some critical files with daily updates (as for Evernote note files, or the database for my password management application, etc.)
2. Encryption of all comms (I don’t want to leak my passwords or my bank account data).

Solution

I was clearly influenced by several factors in my choice, and I will try and make these explicit (your solution may not be strictly identical to mine). So, let’s start by what I chose to deploy.

A smal file server (a Synology DS413j) at my home. It hosts 4 hard drives of 3 TB (initially, four Western Digital RED) in SHR/RAID 5 mode for a total capacity of 6 TB.

The large capacity was defintely dictated by the the need to host a large multimedia server and a large quantity of digital photos (Today, we have altogether much more than 100.000 pictures on this server).

The choice of RAID 5 was a very early one because of its optimum balance between overall dedundancy (you can loose one hard drive with no data loss) and cost (you loose less data to redundancy than in other two-disk RAID configurations). The Synology SHR technology is even better because is allows disks with different capacities (the two smaller ones define the maximum capacity. So, you’d better have one 500 GB with three 4 TB bigger ones; It would be a waste) and it accepts (like all RAIDs) to replace one failed drive with a new one (during the rebuilding of RAID/SHR, you have no more data protection but this is temporairy – and you can keep working in paralle).

Going to Synology was even more justified by a single important item rarely listed in RAID sevrer comparisons: The software offering is specially attractive at Synology. DSM (Synology OS) hosts  “packages” for many applications. The complements I installed (see below) are provided as ready-to-use instalations and can be easy to install even if you have minimal understanding of the inner workings of a server.

So, I was able to deploy a two-stage solution:

1. PC-to-Synology synchronization (three PC via Cloud Station Server)
2. Synology-to-Amazon synchronization (Amazon Cloud Drive through Cloud Sync)

Cloud Station Server and Cloud Sync are two applications from Synology which are installed in about 5-6 minutes (including download time) from the  “Packages Center” of Synology DSM.

If we start looking at the synchronization between PC (or iPhone) and Synology, merely opening the Cloud Station Server in the list below (in the management interface of my Synology DS413j DSM) leads us directly to a menu allowing to download the Windows application (or iPhone app) to install before starting synchronizations between PC and Synology cloud server.

A few clicks and it’s done. Nothing could be simpler. a few minutes and synchronization is starting. It runs in background (it does not hinder normal PC activity) and you will only notice the new change to the file icons showing that it is already synched ot the cloud (see examples below) or that it is still waiting for synchronization (blue tag).

At this point, PC are synchronized, via the Synology server. You can consider that this is a backup since I chose to keep all most recent 32 versions of each file modifications and to not let Synology wipe deleted files (they are stored in the server dust-bin). So, this is a Time Machine feature on top of a backup.

Important notice: The synchronisation between PC and Synology cloud server is very fast and does not eat up resource even on a small/old PC (contrary to some backup programs I would not dare name, like Cobian Backup). this is re-assuring: The end-users can forget about the backup running in the background, stopping if the PC goes to sleep and starting again when it wakes up. This whole process has nearly no impact on the PC behaviour.

Similarly, the iPhone and iPad can use synchronization (of some files, I don’t want them overwhelmed) when on the move.

The second feature replicates these data to another location (here, I chose to synchronize with Amazon Cloud Drive aka ACD because its cost is only 70€/an which appears very reasonable and can be reduced if you have Amazon Prime and a lot of photos). I understood that transfer speed would be limited by my RAID server (the DS413j is quite old and has a very cheap ARM CPU, but it defintely did not break the bank) rather than my bandwidth (I have optical fiber broadban) or by Amazon (all users observe that Amazon is going fast).

Synology Cloud Sync provides this in a matter of a few clicks. Just provide your Amazon login and password. Synology will do it all for you. Synchronization will start in a minute at most (I tried it with Google Drive too. this is as simple and as fast – bandwidth is quite high, which is a good thing; I thought about trying c hubic from OVH, but Internet comments and face-to-face talks with past users seem to point to a product without the needed performance and reliability you want here).

Observations

A few remarks I may have to add after some real-life use:

• The DS413j has a very small CPU from ARM. the CPU workload stays very high (~100%) during all the synchronization phase.
• The first synchronization is lenghty (several days or several weeks depending on the data volume). I recommend to build the data set progressively (not to bunch all your data on the first day).
• Next synchros will generally be much faster (nearly instantaneous).
• Recently modified files tend to be synchronized first.
• I used Cloud Sync to link my server to Amazon, but there is also a solution to synchronize from Synology to Synology: Cloud Station Share Sync. I did not try it but it could be worht exploring if you already have to geographical locations (A second home? A company with two offices?) and two Synology servers. It seems to be as simple as synchronizing with Amazon Cloud Drive.

• In order to elevate the RAID server reliability, you’d better choose hard drives designed for 24/7 use. I would point to Western Digital RED (specailly designed for RAID servers) or Hitachi UltraStar (24/7 version of the DeskStar drives). Also, if you can avoid having all 4 or 5 identical drives, it will reduce the risk of seeing them all failing nearly simultaneously. See BackBlaze statistics on hard drives reliability.
• You may ask where are my “three backup copies”. I actually have the following:
  • The original files on a master PC
  • A manually-copied copy on a separate hard drive (at least one, sometimes two or three of them on spare drives)
  • A synchronzied copy on the Synology server
  • A synchronized copy on Amazon Cloud Drive
• While the Synology DS413j is no longer listed, you can stil purchase the DS416j ou DS418j.
• On the Synology NAS server, I ensured that the synchronized directory is not visible to Windows: A ransomware can’t see it, it would have to hack through the Synology software. this is protecting me against those ransomwares which try to encrypt netork drives too. (Anyway, I can still control my data through the web interface of DSM).
• If a ransomware tries to encrpyt my files (they may then be synchronized in encrypted form), I made sure that versioning is enabled on Synology (This way, I could travel back in time and avoid “paying the ransom”).