Bootable Time Machine Like Cloud Backup?

[dai-leung]

But it's not recommended to back up the entire hard drive with Arq. It's not even recommended to back up your /Applications folder with it. Arq is meant for critically important data: documents, photos, videos, projects, etc. And all of that exists in your Home-folder, and is covered by Arq by default (unless you've manually put the data somewhere else outside your Home folder somehow). But by adding the whole hard disk you'll add totally "useless" system-files to your backup, which will add hundreds of thousands of small and useless system-files to Arq's database, which will make the Arq database massive and slower. And you'll make all backup/validation run extremely slow since you'll force Arq to scan all those files too, even though they're useless.

In fact, it doesn't even make any *sense* to try to back up the entire system with Arq. Because Arq cannot restore any of those system files. You'll need to have a fully working and installed macOS system up and running already, to even be able to open up Arq and be able to restore any files. And at that point, macOS itself will disallow Arq from overwriting the system files that you are "trying to restore/download via Arq".

So don't add your whole hard disk to Arq. Just don't do it.

Arq's restore process works like this:

- Reinstall macOS (if you've lost it).
- Reinstall your applications.
- Install Arq.
- Connect to the backup location.
- Download your important documents, videos, etc, that you want to recover.

Your applications, your main OS files, etc, aren't important (they're totally generic and replaceable) and can easily be replaced by re-installing your OS and your applications.

There are users who have been looking for a way to do a bootable time machine backup because they have been relying on time machine for backup and many of them whose data had been rescued by TM.

It seems possible to use ARQ to create an bootable time machine like backup in the cloud, or on a local external drive or both. This is achieved by backing up the entire Machintosh HD. Except ARQ does not have the time machine's graphic interface showing star-war like multi backup windows at the same time.

ARQ simplifies online backup to a degree even a non computer person like myself finds it easy to use. But ARQ seems able to back up the entire Mac HD is not generally known.

Below are just opinions and ideas, no proof.

Why Not To Backup the Entire Machintosh HD?
ARQ recommends backing up just the home folder, which is also the default backup folder, and it does not recommend backing up the entire Mac HD. @SteveJobzniak, an ARQ expert and an experienced programmer, explained why in (https://forums.macrumors.com/threads/arq.2017935/page-6), quoted above. (Note that he didn't say it can not be done.)

Despite these good reasons not to backup the entire Mac HD, there are users who are still interested to do that due to special needs. One of such needs is the desire to have (after restore) all their applications working again without the trouble of re-installation and re-entering key codes that they no longer have. For non technical users, another need is to have peace of mind, knowing that he has everything needed to restore his Mac.

Can ARQ Backup the Entire Mac HD online?
Through Q&A, an ARQ support recently provided me the following instructions to backup the entire Mac HD online (I am a Dropbox subscriber):

"It's not possible to change the home folder to the entire Mac internal drive directly. Please select the destination under 'Configure Backups' and click 'Add a Folder to Backups'. Select 'Macintosh HD' from the list.

You can then select 'Macintosh HD' under 'Configure Backups' and hit 'Edit Backup Selections'. Uncheck the home folder from there if it exists as a separate backup job already."

So the answer is yes.

Bootable and Time Machine Like
When backing up the entire Mac HD, ARQ performs a similar function as the Restore function of the Mac Disk Ultilities by cloning the Mac HD to an external HD. The restored drive is thus bootable. See for example, https://www.lifewire.com/use-disk-utility-to-clone-macs-drive-4042367 . (Both approaches may not backup the recovery partition volume.)

After the Mac HD is selected to be backuped by ARQ, subsequently many backups will be made at different time points, for example, hourly and each hourly backup is saved and each backup can be used for future restoration. These backups resemble the backups made by time machine except without the TM's user graphic interface.

A Local and An Online Bootable Time Machine Like Backups
ARQ can backup to an external drive (see https://www.arqbackup.com/documentation/pages/strategy.html and https://arstechnica.com/civis/viewtopic.php?f=19&t=1324687 , last post by Malatesta). From the instructions given by the ARQ support, just like backing up to the cloud, ARQ can also backup the Mac HD to a local external drive. Furthermore, it is possible to create two such backups simultaneously, one in the cloud and one on the local external drive as ARQ can backup to multiple destinations. This has the advantage that it uses a single program for both backups.

Restore to An External Drive
I asked ARQ support, after ARQ backing up the Mac HD, whether it was possible to restore it to an external drive. And her answer is :

"Yes, you can restore to an external drive by dragging the folder.

You can not drag the computer's name (she meant the Mac HD backup) on the left of Arq, as you would need to expand the backup set and select a timestamp backup record first. Then you can select an individual file/subfolder or the whole main folder for restoring by dragging it where you want."

So, the answer is yes.

Let's assume there is a data lost catastrophe, and further only the ARQ backup in the cloud survives. In such situation, time, effort and cost spent to recover the data are not important factors. To restore, one has to first download the ARQ program to a Mac (new or old) with an OS installed(see quote above). If a newly formatted external drive (either SSD or HD, assume) is connected to the Mac, a specific time point of the ARQ backup of the Mac HD can be selected and then restored by "drag and drop" to the external drive. See, for example, https://www.haystacksoftware.com/blog/2010/08/how-to-restore-to-a-new-computer-using-arq/ and https://www.arqbackup.com/documentation/pages/restoring.html.

The restored external Drive is a clone of the lost original Mac HD and thus should be bootable. If desire, one can then use Carbon Copy Cloner or the Mac Disk Ultilities to restore the clone to a new Mac HD.

Restore to a New Mac
Assume the new and lost Mac have the same OS version, another restoration approach is to directly restore the ARQ backup to the new Mac and chose "Adopt This Backup Set". Then, it is not sure what will happen next because the new Mac's OS will not allow the /System folder to be overwritten. This could either (a) prevent the restoration or (b) it will restore every folders except the /System folder. If it is the former case, it can be solved by excluding the /System folder from restoration or download the /Applications, /Library and /User individually. If it is the latter case, then the restoration will be successful as the two OS versions are identical, the two /System folders are the same and it does not matter which one is used.

Extra Time Wasted for Initial Backup, Data Validation and Restore and Extra Cost of Storage
My Document folder is 500GB. A clean install of Sierra is 10GB. Thus, comparing backing up only the Home folder vs the entire Mac HD, the extra bytes is 10GB. The extra time wasted for initial backup, validation and restore, each activity is 2% longer. Cost of storage is about $0.005 per GB per month. Thus, for 10G extra data, the extra cost is 60 cents per year.


ARQ may attract more non technical Mac users who are interested in online backup if ARQ will develop an user interface similar to time machine. I believe there are many more such users and time machine followers than highly technical ARQ users.

I hope expert ARQ users can comment if the above make sense or is totally wrong.