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Comment by aidos | Hacker News Reader

I also use Arq and recommend it to everyone on OS X. It has a sane transparent format (modelled on git), it can store to Glacier and it doesn't periodically explode like Back Blaze used to.

Interested to hear more about your "system image". How do you do it and what do you store in it? Documents / preferences / Library etc? How would you use it in a recovery situation?

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It's a separate backup vault in Arq that's maintained by clean OS install + my essential documents, dotfiles, and an encrypted PII volume with scans of passport/SSC/Drivers license/Birth certificate. It's all on a 60GB SSD that's booted every week to update to the latest versions of everything and then to be Arq backed up.

Restoration is downloading the vault to a new SSD and shoving it in a computer. The "root" user is included in the backup as an encrypted volume. My setup's a little strange in that the OS disks on my computers are filevaulted and each user's homedir is also in an encrypted volume only they have the password too that's mounted to the correct /Users/folder with fstab.

(It'd probably be helpful to note that I have a hackintosh this is done on with 10 internal bays, in which one resides this SSD with a clone of this SSD elsewhere)

Could you write that up in a blog post please? I'd love to read how that works. (I'm the author of Arq)

I could probably whack something together, but what specifically were you wondering about?

I'm wondering about the whole process. It sounds like an external drive that you periodically copy your documents, dot files etc to, and then let Arq back up? Or is it something else? (You talk about "booting" the disk -- do you mean booting the computer from that disk, or just mounting it?) Also I didn't understand the "root" user part. And is this a multi-user computer? You mentioned something about "each user".

Ah, I suppose I should break down my setup.

My main system: Hackintosh -- core i5 / 32GB RAM / GTX680, 2 x 250GB SSD, 2x 60GB SSD, 6 x 3TB 7.2K drive. (The handy thing here is my hackintosh build runs the vanilla kernel and I patch all my kexts at runtime so all the binaries are stock -- thus the backups are portable). This is my workstation and it's primarily a single-user system but there is the occasional remote user login. I use this same setup on all my macs though, and this is how it works:

   1 60GB SSD for the OS, applications, and caches
   X number of SSDs (usually 256GB), one for each user

The 60GB OS SSD is filevaulted with a password known to all users, so the disk is FDE'd while any of us can boot it. Each user SSD is filevault encrypted with their personal key. Each user is assigned a bash alias to mount their drive (So you can paste keys if you're using pubkeys with secure entry):

       maroch='diskutil cs unlockVolume <logicalvolumeid>' ##mount aroch's home directory

And there's the associated fstab entry

    /Volumes/aroch /Users/aroch hfs rw,bind 0 0

The "root" account is an admin account setup much the same way but but it is just an encrypted DMG and is mounted at boot using launchd and a hardware dongle as the password. If no dongle is present, there's a non-admin account with a real homedir that can also be used to elevate into an admin shell

The 60GB backup SSD (in slot #4): An install of (now) OSX Mavericks that includes my standard set of homebrew installs, xcode and the ~20 applications I use daily + Arq. It also has the a backup of my fstab and the root account DMG. There's a daily cron that copies my personal dotfiles to it as well. There's a weekly cron that reboots the workstation into the backup SSD and there's a startup script on the backup SSD that checks for system updates /MAS updates, applies them, Arq backup (Takes ~10mins usually) and then reboots back into the main OS SSD. The files total about 17GB right now but the delta is usually less than 100mb.

If needed, the OS and settings can be restored with Arq by using the backup SSD's vault

Wow! That is an impressive setup!

sounds like an awesome setup. So in theory you could restore your backup system drive from the workstation to a laptop as you are running the vanilla kernel ? How would one do that in practice ? I was thinking about a way to sync my workstation and Laptop in an easy way on a system level at night/morning..would something like this work for that ? EG using the nightly system drive image of the workstation and clone it to the laptop in the morning ?

Yes, in fact I have restored from my workstation to my mac mini and MBP in the past. Closing across two drives daily is probably not worth it. You'd be better off rsync / rdiff over your local network

ok sounds reasonable, but can you also sync system files (like installed homebrew etc) that way ?

Yes, you can sync /opt/ and make sure to have some key excludes in there (/var/ and /etc/ being the most likely)

I just needed to upvote you for creating Arq. For a developer it's easy to guess at what it's going to do and it doesn't ever seem to do anything it shouldn't.

There is one question I've had about it. I keep everything in Glacier (about 700GB, I think). My understanding is that nothing is deleted from Glacier. If I deleted a whole backup set and then re-added it, would it upload the content again?

Also, I'm keeping an eye on http://www.filosync.com and I'm planning on trying it out soon. We currently run aerofs which is mostly really good - but sometimes we get into a situation (of our own making, we run it on an aws spot instance that can vanish) and sorting it out is hard work (and time consuming). The most frustrating aspect is that we don't know how it works, so we don't know what to expect when we perform certain operations. Sometimes it doesn't work how we expect and that bites us (I'm currently waiting for 12GB to sync - even though all the machines already have all the content).

Given my (really positive) experiences with Arq I'd like to try a product that was a bit more open about how it worked.

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