Déjà Dup

Backups just got very slow

Asked by Max Ehrlich

I have been using Deja-Dup for a while now, and it usually performs ok. My dataset is 2.2 TB large, and I have been making backups for about a year now. The initial (full) backup took about a day and a half, and after that each backup took between 1 and 2 hours to compute the difference and backup the changes. This is fantastic performance for such a large dataset.
The last two backups, however, have been extremely slow, and disk usage on my backup disk has skyrocketed to the point where I am in the second day of the backup now and I am worried that I will run out of space before the end. The log for both backup sessions shows its backing up every file in the dataset.
Why is this happening? My understanding was that Deja-Dup would backup only the changes, this is the main reason I use it over other backup methods. This dataset is in RAID 5 and rarely changes so backups need to (and should) be fast and small.
Is this a bug or is it by design? If it is by design can I turn it off?

Question information

Language:
English Edit question
Status:
Answered
For:
Déjà Dup Edit question
Assignee:
No assignee Edit question
Last query:
Last reply:
Revision history for this message
Michael Terry (mterry) said : 		#1

Occasionally Deja Dup will make a new fresh backup. See https://live.gnome.org/DejaDup/HowItWorks#Full_Backups for rationale.

Do you think you might be hitting that?

Revision history for this message
Max Ehrlich (queuecumber) said : 		#2

Possibly but it happened twice in a row, that doesnt seem normal. I ended up hitting resume later on the last backup because disk space was getting low and the computers resources were needed elsewhere. After waiting for about another half hour with the duplicity process using between 70 and 100% CPU I just killed the process so hopefully my backups arent all messed up now.
Either way I was planning on wiping the old backups out and starting over because I dont expect this issue to actually get solved.
Is there a way to disable the later full backups unless it is absolutely necessary? For that matter, does Deja-Dup keep a more full features text configuration anywhere? The GUI is very lacking in options.

Revision history for this message
Michael Terry (mterry) said : 		#3

The GUI is very lacking, and no, it doesn't have a hidden config that allows more features. It's designed for simple use cases. More advanced back up programs are available (like maybe Back In Time?).

You could also use the same command line tool that Deja Dup uses under the hood: duplicity.

As for the slow down, I'm still not sure what would cause the slow down besides the fresh backup issue... :-/ Deja Dup is rarely a speed demon regardless.

Revision history for this message
Max Ehrlich (queuecumber) said : 		#4

I love deja-dup because it works and is well integrated with gnome, at least on the fedora distribution I use. But I can't help thinking that sounds like a Microsoft development model. Are there any upstream plan to include a file-backed configuration?

Revision history for this message
Michael Terry (mterry) said : 		#5

No. Deja Dup has an intentionally limited scope: https://live.gnome.org/DejaDup/Mission

Now, it uses a 3rd party command line tool, and it would be delightful if a more complicated backup app appeared using the same format/tool. That way the same data could be shared between the simple app (Deja Dup) and a more complicated one targetted at power users.

Revision history for this message
Max Ehrlich (queuecumber) said : 		#6

Now that's a good idea, something a more powerful but tight integration so it wouldn't be a hassle for an IT administrator or someone to examine a users settings make some changes? I'm going to scope out the effort of such a project I'll keep you updated. Do you want to take this discussion off launchpad?

Can you help with this problem?

Provide an answer of your own, or ask Max Ehrlich for more information if necessary.

To post a message you must log in.