Re: incremental rdiff-backup takes long

[Jonas Schöpf]

Hi Patrik!

On 6/1/21 4:48 PM, Patrik Dufresne wrote:
> Hello Jonas,
> 
> Welcome to rdiff-backup ! Let me try to help you a bit more with you
> problem.
Thanks :)
> 
> First, the first backup always take alot of time because rdiff-backup is
> not like a simple copy and alot of overhead are done in the background
> to put in place the first version of the data.
> 
> Second, with your use case of 400GB, I would not expect a very long
> elapsed time for subsequent backup. I have a couple of backups with
> similar size and it roughly takes ~10-20 minutes over the Internet with
> 400Mbps. But you might not have the same setup as I do.
> 
> If $HOME and $DRIVE are both local, It's quite simple to narrow the problem.
> 
> While running the backup with you command line, you might want to check
> how the IO of your computer behaves. In the command line, try executring
> `iostat -x -m 3` and take a look at the '%util' column. It displays the
> percentage utilisation of the disk. If the value is near 90%, you have
> found the culprit. The IO is your bottleneck.
> 
> To help the situation, you might want to run the backup without fsync.
> When Fsync is enabled, it forces the system to wait until the data is
> written to the disk and persisted. For slow drives on USB, it may have a
> huge impact on the performance. So try running rdiff-backup with
> `--no-fsync`.

Thank you for your help.
Sounds like this is the problem!

I will try your this tomorrow and report back if it works :)

Thank you all for your help!

Cheers,
Jonas


-- 
GPG fingerprint: 0BF3 B30B F1D5 6556 795E  F68F 8626 F794 FE62 BE1F