Can you confirm your dropbox config for rclone please? In particular what is the value of chunk_size?
I see your command as this which looks quite vanilla.
rclone: Version "v1.59.2" starting with parameters ["rclone" "sync" "/mnt/store/snapshot-20221015_090342" "remote:mac-backups-raspberrypi" "--log-level" "DEBUG"]
You can make rclone use less memory by decreasing chunk_size and decreasing transfers.
--dropbox-chunk-size SizeSuffix Upload chunk size (< 150Mi) (default 48Mi)
--transfers int Number of file transfers to run in parallel (default 4)
However you have 8 GB of RAM so this sounds like it is a more general problem.
A 32 bit OS on an 8GB Pi should be able to use 2GB or 4GB of RAM depending on exactly how the kernel was compiled which should be ample for rclone.
You can run with --rc and use the memory profiling tools - I don't think there is a memory leak but perhaps there is some interaction between the 32 bit OS and the Go runtime.
Before your above message, I had just --check-first' and load ran for 1h19m, uploaded 59 GB, then gave the Out of Memory error.
After your recommendation, I changed it to --check-first --dropbox-chunk-size 20Mi --transfers 2 it ran for 2h20m uploaded 80GB.
This seems to have done the trick = PASS.
Then I also tried --check-first --dropbox-chunk-size 20Mi --transfers 6. Increased the transfers, to get better throughput.
And this worked as well. Ran for 1h42m Uploaded 107 GB.
I see you sometimes use --check-fist and sometimes not, so just in case you you missed @asdffdsa's initial post: --check-first may increase the memory usage:
Using this flag can use more memory as it effectively sets --max-backlog to infinite. This means that all the info on the objects to transfer is held in memory before the transfers start.
I therefore suggest you omit --check-first unless you have a very specific need and then you may be able to reduce memory usage further by lowering --max-backlog, the default is 10,000. More info here: https://rclone.org/docs/#max-backlog-n