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A performance comparison of Duplicacy, restic, Attic, and duplicity

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Re: A performance comparison of Duplicacy, restic, Attic, and duplicity

#31

Post by tombrossman »

GordonS wrote: post #25
tombrossman wrote: post #12

Earlier quoted context omitted.

How much data and what's your monthly cost? I have a 2TB storage VPS for under $10/month. rsync.net looks very good but is possibly total overkill for my needs. Definitely don't need >1 snapshot/day as that's what my hourly local backup is for.

Can I ask where you got the VPS? That's a really great price for 2TB!

At present I'm using a provider in Lithuania called time4vps. Overall the service is good (assuming you are connecting from Europe) but to use their website I have to disable my ad-blocking & privacy add-ons, which I don't have to do on other providers' sites. Not sure why that is.

I'll probably try Delimiter once they start offering service in London, as they also have some similar low cost + high storage plans.

Re: A performance comparison of Duplicacy, restic, Attic, and duplicity

#32

Post by willvarfar »

ams6110 wrote: post #27

> duplicity has a serious flaw in its incremental model -- the user has to decide whether to perform a full backup or an incremental backup on each run. That is because while an incremental backup saves a lot of storage space, it is also dependent on previous backups due to the design of duplicity, making it impossible to delete any single backup on a long chain of dependent backups. So there is always a dilemma of h…

Classic source control had this problem.

The clever trick is to reencode the previous most-recent backup as a delta from the current state, and do a full-backup of the current state, rather than encoding each new backup as a delta from the previous state (which becomes slower and slower to compute, the more previous states you have).

Problem solved :)

Re: A performance comparison of Duplicacy, restic, Attic, and duplicity

#33

Post by flipbrad »

atonse wrote: post #2

Is anyone using such tools as a backup for their NAS (and then using their NAS for time machine?). That would beat having to install something like Backblaze on every family member's machines. Cloud backup is great but it's always better to have a local (LAN) copy and then an off-site copy.

Duplicity is pretty easy to use with Backblaze B2 as a cloud storage backend - that's what I use to backup my NAS.

Re: A performance comparison of Duplicacy, restic, Attic, and duplicity

#34

Post by beagle3 »

i think bup does support concurrent access; the concurrent deduplication granularity is a backup set, so if two identical computers are backed up for the first time at exactly the same time you will not get deduplication - but that's inherently a dining philosopher kind of problem

Also, recent bup versions allow delete. No encryption IiRC, but you can examine it with git tools which is a feature on its own.

Re: A performance comparison of Duplicacy, restic, Attic, and duplicity

#35

Post by comice »

acrosync wrote: post #30
comice wrote: post #28

Earlier quoted context omitted.

"It's a shame Duplicacy is not free software." If the commenter meant no cost it's more reasonable they'd have said "It's a shame Duplicacy is not free". Or "It's a shame Duplicacy costs money". Capitalising would have made it clearer yes, but I think given the language and the context (hacker news) I was justified. But the author, @acrosync, was also justified in assuming it meant no cost.

Free or not free aside, my question is, does it matter to personal users between this free-for-personal-use license and any of those more permissive licenses like MIT, BSD, or GPL?

It matters to me as a personal user because my use of duplicacy might change at some point and suddenly I'd lose rights to use it (unless I pay). I'd lose rights to any development contributions I might have made unless I pay.

And as a personal user, I can't use any code from Duplicacy in any other project. I can't even, say, create a package for it and get it included in Debian.

And aside from some of these practical issues, I'm a personal user who supports software freedom so I don't want to use something encumbered in this way.

And as a commercial user, any development contributions I make are no longer my own and I have to pay to make use of them.

But the worst part of it is, your license isn't very well defined. As it stands, you may at any point stop accepting license payments from a commercial user and they'd lose the right to use it entirely - they'd lose access to their backups (unless they used the software without a license).

You of course have the right to choose any license you like! I just wouldn't use duplicacy myself under the terms of that license.

Re: A performance comparison of Duplicacy, restic, Attic, and duplicity

#36

Post by Theriault »

acrosync wrote: post #30
comice wrote: post #28

Earlier quoted context omitted.

"It's a shame Duplicacy is not free software." If the commenter meant no cost it's more reasonable they'd have said "It's a shame Duplicacy is not free". Or "It's a shame Duplicacy costs money". Capitalising would have made it clearer yes, but I think given the language and the context (hacker news) I was justified. But the author, @acrosync, was also justified in assuming it meant no cost.

Free or not free aside, my question is, does it matter to personal users between this free-for-personal-use license and any of those more permissive licenses like MIT, BSD, or GPL?

It's stopped me from using it for personal use.

From a practical standpoint, it makes it more difficult for me to trust that it will be maintained in the long-term, or that I can extend its functionality if I see a need.

Ideologically, I'm somewhat uncomfortable using duplicacy when fully-free alternatives exist. I'm not a free software purist by any definition (I use steam. I have a Netflix subscription. My android has google apps on it.), but this is an area where compelling free software solutions do exist.

The license also keeps it from being packaged in most Linux distributions, which makes it a nuisance.

Re: A performance comparison of Duplicacy, restic, Attic, and duplicity

#37

Post by hedora »

acrosync wrote: post #30
comice wrote: post #28

Earlier quoted context omitted.

"It's a shame Duplicacy is not free software." If the commenter meant no cost it's more reasonable they'd have said "It's a shame Duplicacy is not free". Or "It's a shame Duplicacy costs money". Capitalising would have made it clearer yes, but I think given the language and the context (hacker news) I was justified. But the author, @acrosync, was also justified in assuming it meant no cost.

Free or not free aside, my question is, does it matter to personal users between this free-for-personal-use license and any of those more permissive licenses like MIT, BSD, or GPL?

I hate switching backup software, and with your current license, you become a single point of failure--will you be supporting this thing in 10 years when I need to back my FireflyBSD 128-bit RiscV machine up to the walmart cloud (or whatever random os/hardware/cloud is common in a decade)?

If this were BSL licensed, the community could fork it if that became an issue:

http://monty-says.blogspot.com/2016/08/applying-business-sou...

I'm curious to see whether any BSL software manages to build a third party dev community (inclusion in debian non-free, third party patches and bug reports, etc)

While I have your attention: It'd be great to measure how many bytes the solutions read and write, as well as I/O counts. There are tools for this in Linux, and probably MacOS. Alternatively, network bandwidth would be a good proxy for these measurements.

Re: A performance comparison of Duplicacy, restic, Attic, and duplicity

#38

Post by AdmiralAsshat »

I would've been curious to see how BackinTime stacks up.

Duplicity/deja-dup (a GNOME frontend for duplicity) is pre-installed on most GNOME-based DE's, which makes it convenient for end-users, but I found the limitation of only being able to configure a single backup destination to be too limiting.

By contrast, BiT supported multiple destinations and profiles, meaning I could have one local, one off-site, one "Personal Data" backup, one "System" backup to fall back if an OS update fails, etc. Its configuration options were much more attractive.

Re: A performance comparison of Duplicacy, restic, Attic, and duplicity

#39

Post by e12e »

It's a little odd to not benchmark backup over the network - a backup taken to the same physical disk as the source of the data isn't very useful - for that use-case taking a filesystem snapshot[s] would probably be faster and more useful. Perhaps in combination with a checksumming tool, like [c], or with a filesystem like ZFS.

Also, it can be difficult in a lot of environments to sustain more than 100mbps write to a remote, off-site system - halving the stored data can be a much bigger win then.

All that said, it's interesting to see that a) duplicity seems slow, and b) very consistent in terms of speed. I wonder if there's some low-hanging fruit for optimization there.

Personally I've had some luck using backupninja[b] in combination with duplicity. It's one of the few Free alternatives that allow the backup-system to encrypt "one-way" - so that compromising the backup-system doesn't immediately give read access to encrypted backups. It's a bit complicated to set it up for separate encrypt-to and signing keys though :/

[s] Today I would probably recommend ZFS - but I've always wanted to give NILFS2 a real test, especially on solid-state disks: http://nilfs.osdn.jp/en/

[c] https://github.com/Tripwire/tripwire-open-source

http://aide.sourceforge.net/

https://github.com/integrit/integrit (Speaking of projects that might be fun/useful to redo in a safe language like rust or go - it would appear this would be a prime example, btw. On the whole moving integrity to the fs, as with zfs might be the better option, though).

[b] https://0xacab.org/riseuplabs/backupninja

Re: A performance comparison of Duplicacy, restic, Attic, and duplicity

#40

Post by _JamesA_ »

Theriault wrote: post #36
acrosync wrote: post #30

Earlier quoted context omitted.

Free or not free aside, my question is, does it matter to personal users between this free-for-personal-use license and any of those more permissive licenses like MIT, BSD, or GPL?

It's stopped me from using it for personal use. From a practical standpoint, it makes it more difficult for me to trust that it will be maintained in the long-term, or that I can extend its functionality if I see a need. Ideologically, I'm somewhat uncomfortable using duplicacy when fully-free alternatives exist. I'm not a free software purist by any definition (I use steam. I have a Netflix subscription. My android…

It is an issue of trust for something as important as a backup tool.

Duplicacy sounds great but it has 6 [0] contributors and Borg has 107 [1]. It's obvious which one has more eyes on it.

Plus I can apt-get install borgbackup / apt-get upgrade which adds another level of trust.

[0]: https://github.com/gilbertchen/duplicacy

[1]: https://github.com/borgbackup/borg

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