I’m about to run out of disk storage for my Lightroom image catalog, so in preparation for a new iMac — one that supports a Thunderbolt disk system — I’ve decided it’s time to upgrade my backup systems. This is a long blog post, but it thoroughly covers what I’m now using for backup and what I learned in the process of getting to the final result.
My Former Backup Scheme
My backup strategy for the past three or four years was “pretty good”. My first-level backup was from my iMac to an Apple Time Capsule via Time Machine. For the second level, I made two copies at the end of every month of each of my internal SSD and 2TB rotating drive to two pairs of portable USB drives. Why two sets of removable backups? One set I kept off site in a storage locker. The other set I kept here at home for two reasons: (1) I’m actually paranoid enough that I wanted one set always off site (i.e., not in-transit) so I took a new set to the storage locker each month and only then retrieved the previous month’s set. Otherwise I’d have both the old and new sets at home simultaneously; (2) Although I’ve never had to recover from a major disaster like fire or theft, I have occasionally needed to recover a corrupted or accidentally deleted file. Having a full backup here in the house makes that very easy. Sure, I’ve got Time Machine, but I’ve had that completely fail on me and lost everything on the Time Capsule. Time Machine by itself is not an adequate backup solution.
New Backup Requirements
My new requirements are as follows:
- 8TB of usable, local backup storage, updated multiple times/day from my iMac’s internal and external drives.
- An identical server located at a remote location, replicated via the Internet daily and automatically from the local backup.
- 12TB non-redundant Time Machine storage, separate from the above, for versioned files.
After lots of research and testing, here’s what I’ve ended up with:
- (1) Synology 214 DiskStation NAS (network-attached storage) server [US$300] with (2) Western Digital 4TB Red drives [US$175 each] configured as a single RAID0 (striped, non-redundant) disk group in a single 8TB volume for the local backup, connected to my iMac via Gigabit Ethernet.
- An identical system to the one above, but located at a remote location and linked to the first one via the Internet. This is like having my own remote cloud server.
- Carbon Copy Cloner [US$40] app for backing up the iMac drives to the local NAS server.
- A 16GB USB 2.0 flash drive [US$9] as an OS X Recovery Drive.
- Total cost: US$1,349, which doesn’t include my Time Machine storage.
I sync each of the two drives in my iMac to a separate shared folders on the local NAS backup server every six hours using Carbon Copy Cloner. Once a day, at midnight, I then replicate the shared folders on the local and remote backup servers using Synology’s built-in shared-folder syncing. I’m storing the files on the NAS servers in sparsebundles, the same format used by Time Machine. The synchronization uses the standard rsync utility, which transfers only disk blocks that have been modified since the last pass.
I don’t recommend this solution for beginners. I’ve got quite a bit of experience configuring and managing Linux servers, so these DiskStations are almost like old friends to me. Synology has done an excellent job in making their servers easy to setup and manage, but I still think it would be a bit scary and frustrating for someone who wasn’t already familiar with Linux and disk/file servers.
Intermission: If all you care about is the solution, you can stop here. But if you want to understand why I’ve settled on this solution for backup, and the tests and considerations that went into making these selections, read on!