I found it extraordinary difficult to build your own encrypted cloud.
Options:
1. Truecrypt container. CON: Upload takes to long
2. ecryptfs CON Always had problems getting it to work. AFAIK it is not under current development anymore.
3. Run a FS in a mounted contaner (Filesystem in a FILE). Slow. Not very stable. Under no circumstance use ext4 or something like it, if you really want to try this, use ZFS to avoid data corruption
That is why I like ZFS: Its send/recv function can do block level syncing, so while the first upload will take a while, subsequent syncs will be much smaller.
Of course, unless you stand up your own VM with a ZFS partition, there are few cloud options for ZFS.
"CryFS solves all of these issues, but because of the increased security it is a bit slower. It is also a very new project and currently only available for Linux and Mac, but has experimental Windows support in the newest version. So if you don't need Windows support today, you can give it a try."https://www.cryfs.org/comparison/
I tried. I have a 100MBit line. With no encryption I have a very good speed. To get things working I came down to 1% or somethings and very sluggish.
I also remember that my internet provider blocks many ports and I had to use my VPN to get required ports to working. This again scaled things down a little. I found CryFS not usable on Linux
Options:
1. Truecrypt container. CON: Upload takes to long
2. ecryptfs CON Always had problems getting it to work. AFAIK it is not under current development anymore.
3. Run a FS in a mounted contaner (Filesystem in a FILE). Slow. Not very stable. Under no circumstance use ext4 or something like it, if you really want to try this, use ZFS to avoid data corruption
4. CryptFS. Great Idea but slow as f.. https://www.cryfs.org/comparison/
In the end I did not the cloud as a second backup for a large system (10TB) since I found no safe, fast and reliable way.