If I wanted to use rclone to mount a encrypted folder on say a ceph cluster (for nextcloud encryption) would performance be similar/slow like gdrive or would it be fast like luks? I'm assuming the slow performance is google limiting gdrive and not an indication of rclone performance.
Similarly, if I use webdav what would I be looking at performance wise?
The goal is to secure the files in the event of a physical attack and backup. I know nextcloud has encryption but IIRC it's base64 and that imposes a 35% file size increase which I'm hoping to avoid.
I am not familiar with Cephcluster at all, but we are not talking about a cloud storage here but rather an advanced storage manager right? So you would basically be accessing it via a "local" remote from some sort of share? ..
If so you have no worries. Rclone's internal performance is very high and you will almost certainly be limited by your bandwidth or the performance of the storage cluster.
If we are talking about some sort of other remote like FTP being used then it really comes down to the protocol. Most will be very fast as long as they are not rate-limited in any way - but at the same time not all transfer protocols are designed for high performance, so there is some variance.
You can always just make a local remote + encryption on your own system and see. You will probably max out your SSD before rclone becomes a bottleneck I suspect. There is no problem with rclnoe's internal speed.
Depending on the latency to the system you might want to tweak the concurrent transfers a little to optimize throughput, but that should be about it.
Rclone can work at wire speed with a local (or close) cluster. We have a CEPH cluster at work and I often use rclone with it!
Note that if you are using rclone mount you might consider using --no-modtime as the s3 or swift protocol takes an extra transaction to read the modtime.
I have rclone set up as a webdav -> swift on CEPH proxy and it maxes out the 1 Gbit/s connection to the VM I set it up on!
The only difference will be a fairly trivial amount of extra CPU cycles on modern CPUs.
Not something to worry about unless you are trying to do something like push 1Gbit of bandwidth though an old atom CPU or raspberry pi type microsystem.
I think part of this is down to that most relatively modern CPUs have acceleration for AES which is what rclone uses.
On a "normal" system like even my now old 2500K (2011) I can't really notice the difference in load on a 150Mbit connection. No matter the bandwidth I think you would struggle to max out any desktop or server CPU from the last 10 years for that to become your bottleneck.