Synology Hybrid Backup, Part 1

One of the important aspects of syncing is that what you do to one folder, you do to the other. That is, if you save a file in one folder, it will automatically be saved in the other system as well. Similarly, if you delete a file in one, it will delete in the other.

For that reason, Syncing (as a concept) is not backup either.

Why not?

It’s important to remember that backups are only half of the equation; you must also be able to restore. Suppose you accidentally delete a file or folder from your original location and wish to grab it from the remote side. Oooops! It’s gone from there too.

Until you’re more familiar with Synology’s approach, this can wind up becoming a bit complicated, because you have the ability to offset the syncing, which means that you can delay changes to the remote folder. As a result, it is possible to go back and rescue files and folders from the remote location before the next sync process takes place. As I describe it here, it doesn’t sound all that complicated, but when you start to fiddle with the knobs inside the UI, trust me, it helps to understand the bigger picture.

Depending on the size of the data deleted, the ability to copy it back before the delete command is initiated can be troublesome. Either way, the restoration functionality is not part of the normal process, and cannot be considered a backup solution.

So what’s it good for?

Generally speaking, Syncing (and Versioning, too), are about “data availability.” The goal is to prevent errors caused by human errors, viruses, malicious intent, etc., from disrupting the continuity of your workflow and productivity.

Most importantly, and this is what Synology recommends, syncing is great as a “poor-man’s high availability” (my words, not theirs). It’s not really “High” Availability (HA), but about as close as you can get. If your first DiskStation has a catastrophic failure and goes offline, all your data is available on the secondary system (at least, from the last time it was scheduled/available to sync).

You can simply point your compute and mobile devices to the secondary disk station and away you go, while you try to fix your primary system. Just remember you’re flying without a net at that point, unless you have a tertiary mechanism for recovery if that system should fail (e.g., offsite backup, cloud storage, etc.).

Now, DSM 5.2 has the ability for true HA, given the correct models. Unfortunately in my case, the DS1511+ does not have the correct hardware to permit HA configuration. So, for this reason I’m going to have to forego this capability, given my setup.

Syncing is also great for ensuring that multiple devices have access to the latest data, and indeed Synology provides mobile applications that can be connected with a sync’d folder share. Unlike Dropbox’s two-way synchronization paradigm, however, Synology’s – called Shared Folder Sync – is one-way. That is, if you add or delete anything manually on the remote side (which is not easy to do, btw), the original folder is not touched.

Think of it this way: setting up a synchronization shared folder in Synology is similar to setting up a repository that mobile devices can then access.

In Synology’s DSM 5.2 interface, Syncing is found in the Backup and Replication application, found in the main dashboard.

Backup and Time Backup

This is where things get interesting and, also, confusing.

Synology has a number of backup options to choose from, including the built-in Backup and Replication solution (mentioned above). They also have a Time Backup, which, if you’re familiar with Apple’s Time Machine, looks very similar in terms of functionality.

In this case, we’re not working with iSCSI LUNs, but it’s useful to know that iSCSI LUN snapshotting is possible using Synology’s DSM software, with a few additional features specific to iSCSI volumes.

Both of these features – Backup and Sync, have wizards that walk you through the process of selecting the folders you want to sync, and while the basics are there (choose the source, login credentials, there are key behavioral and mechanical administration differences (that we’ll get into in the next article). Also, undoing your configuration is more difficult with syncing than with backup, so make sure you know what type of replication you want (sync or backup) and why!

In my case, Backup helps solve the problem from getting from the DS1813+ to the DS1511+, but it does not help me solve the problem of saving from my Mac. For that, I’ll need another option, such as Cloud Station.

Cloud Station (Backup)

Earlier, when we looked at Shared Folder Sync, I noted that this was a one-way replication method. Sometimes, however, you want to do two-way synchronization, similar to the way Dropbox works. For that, you’d use Cloud Station, which is available in the Package Center:

While I’ll go into further detail later on, the effective process is that you establish the service on the Synology you wish to use as the destination (in my case it’s the DS1813+ in the middle of my diagram at the beginning of this blog), and then use the client software to do the configuration for that particular device (e.g., folders, files to be sync’d).

Remember, though, that this is still a syncing process, not a backup process, until you turn versioning on. Fortunately, Cloud Station gives you the ability to do some versioning control, and I’ll go into that later as it’s appropriate for my workflow.

Synology has put together a video on how to do this, as well.

Cloud Storage

The last piece of the puzzle is the offsite backup. Recently the market trend has been to move to Cloud-based storage, but it’s useful to know some very important caveats.

First, cloud storage is slow. It’s slow getting there, and it’s slow getting back. If you have a single Terabyte of data that you need to restore from a cloud storage location, that process can take weeks over a typical home broadband connection.

Second, you have no control. Cloud providers can (and will) grant you all the access you can pay for, and some will have you handle your own private encryption keys for added security. Ultimately, though, your data is at the mercy of anonymous people who can do all kinds of nefarious things to it. Likewise, should a government agency come a-knockin’ on their door, they do not need to get a warrant for your data. Many cloud service providers will simply hand over private data to government queries, whether they’re criminal investigations or not.

Third, cloud storage companies can guarantee the longevity of your data only for as long as they can guarantee the longevity of their own ability to stay in business. The more data you have located outside your control, the more difficult it is to migrate. A good lesson is the recent demise of Nirvanix.

Yes, you can encrypt your data and no, no encryption method is fool-proof. For these reasons, you should be careful as to what data you decide to store on cloud storage providers.

The best way to look at cloud storage is as your “last resort” option. I’m not saying that you set up your cloud storage as a last resort, I’m saying that you should have several restoration options before you get to cloud storage – but have some type of offsite storage as a last resort!

It’s the insurance policy you hope you never have to use. Just like an insurance policy, too, you’ll pay for the privilege of that protection, so choose your level of service with careful forethought and planning.

Synology assumes you’ve thought this through already, as well they should. It’s not their responsibility to hand-hold people through the best practices of cloud storage decisions, mostly because there are so many different options to choose from that the appropriate answer to any question is, “it depends.”

Synology does, however, provide a wide array of options for you to choose from, including some built-in tie-ins to a wide variety of options, expanded with version 5.2. This includes Google Drive, Dropbox, Baidu, OneDrive, Box, hubiC, Amazon S3, iDrive, and several others, including OpenStack Swift. These choices can be bewildering at first, so it pays to do some up-front research.

In a later article I’ll be going over my specific example for cloud storage in detail.

Getting Started

Now that I’ve laid out the foundation for a Hybrid Backup Solution with my Synology setup, it’s time to actually get started. In the next article, I’ll go into specifics of how I managed to get the data from different internal hard drives inside my Mac to the first DiskStation. Following that, we’ll back up everything to the second one, and then finally offload a smaller subset of that data to a cloud storage offering.

P.S.

I’m very pleased that this has been useful, and I want to make more posts like this with updated hardware and software, so in order to do that I’ve recently created a Patreon account. If you want to see more posts like this – about Synology or anything else to do with storage – please consider sponsoring future content.