Re: Speed and regression

[Duffer]

On 2024-09-25 22:30, Duffer wrote:
> Hi.
>
> I'm using rdiff-backup 2.2.6 for a large amount of data. All traffic is 
> encrypted via stunnel.
>
> I have two concerns:
>
> 1. Speed
>
> With SSH, the speed I've seen is 25-50 Mbps, probably averaging 30-40 
> Mbps. iperf3 gets around 500 Mbps between my local system (destination) 
> and the remote system (source). The SSH speed seems excessively slow to 
> me - maybe 6-8% of the measured bandwidth.
>
> I switched to mapping the data source via NFS. Now I'm seeing full 
> speed for the transfers.
>
> Why is SSH so incredibly slow? Is that expected? I'm okay using NFS but 
> I liked the convenience of SSH.
>
> 2. Regression
>
> As noted, my backup was very slow so I stopped it (CTRL-C). The next 
> time I ran the backup, it went into "regress" mode, so I lost all the 
> progress. Is there no way to avoid this and resume somehow? I couldn't 
> find anything in the FAQ.

The regress didn't take long at all but it's now been running over 10 
hours and I've seen little progress. Disk usage hasn't increased at all. 
Is this expected? I thought after the regress it would start 
downloading, like it did before. I can't tell what it's doing but I seem 
to see it reading a lot from the disk. I used "-v 3" but maybe I should 
have opted for more output.