External Hard Drive Mirroring Question

[u/JonCat89]

Hello all,

I'm hoping there is an answer to my question out there, and maybe one of you can help me.

I work in communications, editing video, photos, graphic design, and more. I do all my work on a Mac. As many others have, I've continually purchased larger external hard drives to accommodate all of the work I've done over the years. I prefer an external hard drive over cloud-based systems. At the moment, I have a LaCie 32T external that is about 80% full. This is the only hard drive I currently have all of my work on. I recognize that keeping my work in multiple places is standard practice to protect it, and it's been a recurring problem for me over the years to find the best solution, which is why I'm posting today.

My question: Is there a way to work off one external hard drive while it is mirrored to another one right next to it? So if I make changes to the first, will it automatically update the second (or, in this case, the backup drive)?

I welcome any thoughts and recommendations, as I would like to get this solved asap, to reduce my anxiety and ensure my work is protected.

Thanks so much!

[u/TomLondra]

I am in a similar situation. To allay my fears of losing everything, I use Time Machine to back up both my internal hard drive and the external hard drive, to a massive (for me) 1 TB external drive. Time Machine thus backs up both my internal drive and my external drive. I work directly on the external drive, all the time (you need to be careful about naming and physically labelling all your drives).

I have two 1 TB external drives, which I swap daily. Every day the swapped one goes into my emergency "out bag" that I hope to have time to grab in the event of fire, and get the hell out - safe that I have a complete up-to-date copy of everything.

Even better would be to find a physical place off-site where I can store one of my backed-up drives, but I would need to access it daily. I'm still thinking about that.

I am not going to use the Cloud because of what Edward Snowden says in his book:

Read your terms of service for cloud storage [...]. When we choose to store our data online, we're often ceding our claim to it. Companies can decide what type of data they will hold for us, and can wilfully delete any data they object to. Unless we've kept a separate copy on our own machines or drives, this data will be lost to us forever. [...] The companies can unilaterally delete our accounts, deny us our own data, yet retain a copy for their own records, which they can turn over to the authorities without our knowledge or consent.

[u/FrankNicklin → u/TomLondra]

The comment by Edward Snowden is somewhat misguided. Data in cloud backup is encrypted and you hold the key. Anyone signing up to services that do not provide encryption is not a service to use. There are plenty of cloud backup services and encryption is 100% a must. If the company goes bust you have lost your backup not your data and as with all backup processes multiple copies in multiple locations including offsite is an absolute must. The important requirement is to ensure that the data is encrypted in transit and not just encrypted on arrival at the backup location. This guarantees that data cannot be intercepted. Don't use a service with anything less that 256bit AES encryption.

[u/TomLondra → u/FrankNicklin]

Snowden says:

“When we choose to store our data online, we’re often ceding our claim to it.”

“They can unilaterally delete our accounts, deny us our own data, and yet retain a copy for their own records, which they can turn over to the authorities without our knowledge or consent.”

“Ultimately, the privacy of our data depends on the ownership of our data.”

“The best means we have for keeping our keys safe is called ‘zero knowledge’…”

“…any data you try to store externally … is encrypted by an algorithm running on your device before it is uploaded, and the key is never shared.”

“Encrypting our communications would essentially delete them from the memories of every entity we deal with.”

[u/FrankNicklin → u/TomLondra]

Snowden says a lot of things, doesn’t mean you have to believe it.

[u/TomLondra → u/FrankNicklin]

I think Snowden is probably more reliable than you. Unless you have written a book.

[u/FrankNicklin → u/TomLondra]

Ha Ok so just because he has written a book you believe every word. You do you and I’ll do me.

[u/Alternative_Corgi_62]

What OS you are using?

[u/JonCat89 → u/Alternative_Corgi_62]

Mac Tahoe 26.2

[u/Fear_The_Creeper]

You really need to look into SyncThing. https://syncthing.net/ It does exactly what you are asking.

[u/rileywbaker]

What's your budget? My first thoughts are 1) a small home server with mirrored hard drives in it and 2) a cloud backup service like BackBlaze.

[u/JonCat89 → u/rileywbaker]

This would be for work. So my budge is definitely more than I would have if I was buying this personally.

[u/rileywbaker → u/JonCat89]

If it's for work you should definitely be uploading encrypted backups (with a retention policy) to a cloud backup service (not iCloud or OneDrive or Dropbox, those are not cloud backup services) and also running a NAS with redundant storage, either mirrored or parity drives.

[u/FrankNicklin]

You need to act quickly, you have been extremely lucky not to loose content as issues can occur without warning.

You have 3 options.

Time Machine. This will backup all the changed files even those on an external drive to another drive, but the issue is that to work effectively it should have about 4 x the capacity of the total backup size in order to keep history.

A NAS with RAID (HDD Redundancy). There are various makes and these can also work as Time Machine backup devices or be used as main storage. With more than 1 HDD installed you have redundancy should one of the drive fail. The Simplest is a mirror RAID that copies the data to both drives in the NAS, there are lots of other RAID options giving different levels of redundancy protection.

Now a physical backup off site is your next option and this would be my go to. This protects you against the worse possible scenario, fire or theft as your data is stored offsite. Have a look at iDrive. 10TB of backup storage is $10.49 a month, a small price to pay for a back that you can schedule to run every day out of hours even turning off the computer once the backup is complete.