Things to consider when you’re away from home.
I would not expect a huge file copy of an image backup to be reliable, no matter how you do it. So, to put it bluntly, I wouldn’t even try.
However, backing up while on the road is something I’ve thought about a lot — each time I travel, actually, since things are always changing.
Let’s review why sending image backups home is impractical in my opinion, and what I recommend you do instead.
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Backing up when travelling
Image backups should be done locally to an external hard disk accompanying you. It’s impractical to copy them elsewhere, though. Instead, use online backup tools to back up your important files, or cloud storage like OneDrive or Dropbox to automatically save work in progress and simultaneously replicate it to machines back home.
Long distance image
Let’s say you have a gigabit internet connection (approximately 1,000,000,000 bits per second, or 125,000,000 bytes per second).1 Let’s also conservatively say your image backups are 250 gigabytes(250,000,000,000 bytes).2
Under absolutely perfect conditions, it would take a little over half an hour to transfer your backup image from your remote location to your home. “Absolutely perfect” never happens. Several things will significantly affect the transfer time.
To begin with, overhead data transfer rates are more like 80% of rated line speed, at best.
Internet connections compete for bandwidth. That means anything else on your machine using the internet at the same time will slow down the transfer. In addition, you may compete with other network users or ISP customers at either end. For example, if your neighbor is using the internet heavily, it’s possible it could slow down your connection, sometimes significantly.
But it’s about more than internet speed. ALL the equipment in the path — your computer(s), your home network, your NAS — must all be capable of sustaining that speed. Any single device that does not (say one of your devices has a 100mbps network connection, ten times slower that the gigabit internet) becomes the limiting factor.
Pragmatically, copying image backups across the internet takes hours and sometimes days.
It gets worse. The software performing the copy — the backup software directly or the copy command done separately — needs to reliably recover from interruptions. They often do not, and a single hiccup could interrupt the entire operation.
Bottom line: it’s just not practical. Too many things can and will go wrong.
You’re absolutely on the right path by backing up to an external hard disk you carry with you. There are many portable external drives that are perfect for this.
I carry one with me whenever I travel for this exact purpose.
I back up to the external drive, but that’s as far as the image backup goes. I don’t try to send it home or anywhere else across the network. It’s just too big.
That image backup protects you from system failures, malware, and other common issues. The only thing you’re not really protected from is losing both your computer and external drive at the same time.
For that, we take the next step.
Backing up files remotely
It sounds like you’re also using some kind of online backup service that is backing up a subset of your files. That may well be enough.
My approach instead uses tools like OneDrive or Dropbox to back up my work in progress. That way, as files change throughout the day, they’re automatically replicated to the cloud without my having to lift a finger.
This protects me from the scenario of losing everything all at once, because even without my laptop or external drives, the stuff I care about has been copied elsewhere.
As it turns out, that provides a secondary layer of security as well.
Backing up at home
Say I’m on the road, and I work on a file stored in my Dropbox. As soon as I hit save, this happens:
- The file is updated on my local hard disk.
- Dropbox uploads the file to its servers.
- Dropbox then downloads the file to my machine(s) at home which are signed into the same Dropbox account.
- My nightly image backup on my machine at home includes the updated file.
- Any image backup I create3 of the laptop that’s with me also includes the file.
My work in progress as I travel is well and thoroughly backed up.
Not backing up at all, sort of
Honestly, much of what I do these days doesn’t fall into the scenario I list above.
For example, as I type this article, it’s being saved directly to the Ask Leo! web server, not on my machine at all. This would be the equivalent, perhaps, of doing all your work in Google Docs or Microsoft Office Online. The files you’re working on aren’t on your machine, but rather stored natively in the cloud.
That’s convenient as far as it goes, but be careful to ensure the work is somehow getting backed up as well.
My server gets backed up regularly.
My OneDrive, Dropbox, and Google Docs are all included in my local image backups because I have those utilities installed on my machine and configured to download everything, all the time.4
Make sure anything you’re doing online is somehow being backed up. If it’s in only one place, even if that “one place” is an online cloud service, then it’s not backed up.
Don’t rely on the internet for huge file copy operations when travelling, particularly backups.
Instead, make sure you have a strategy that backs up the things you care about appropriately, taking in to account internet speeds and other services and tools you’re already using back home. You may find that something as simple as doing your work in OneDrive or Dropbox folders coupled with the backups you’re already doing at home covers the bill.
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Footnotes & References
1: I’ve never seen that fast an internet connection while travelling. Consider yourself lucky if you have one.
2: Half the size of my primary machine backup, but I’m an edge case.
3: Full disclosure: I do this rarely while I’m travelling. So much of what I work on is cloud-based or cloud-hosted that the image backup of my machine is often more hassle than it’s pragmatically worth. This decision depends heavily on exactly how you use your machine while travelling. When in doubt, back up.
4: All of these services now have options to save disk space by downloading only on demand. This defeats the backup process. On at least one machine with lots of disk space, I have those services configured to download everything, all the time, specifically so they’ll be included in my local backups.