Performance issues on Synology?

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#1

I hope it wasn’t asked before, cause I couldn’t find it -
and it’s not necessarily directly related to duplicacy —

but I have a 250Mbps upload connection which should allow at least 32 megabytes up per second.
Indeed, when i run a duplicacy backup from my PC to a destination near enough, i see these speeds show up (if I use enough threads, e.g. 20)

However, when I run duplicacy from a docker (@saspus 's actually ) on Synology, i get only about 1MB/s upload speed.

Since both machines are connected to the same router and are peers, am I correct in my deduction that Synology’s CPU/RAM (in the 420+ model) is simply not high enough to support such upload speeds in my case - considering the extra compute Duplicacy might require?

or is there something else I might be missing in terms of some kind of configuration (or - for example, is speed capped in duplicacy “Trial”?)

#2

In Synology resource monitor you can check the IO queues and CPU usage (including per core). See if any of the stats is maxed out when you see the slow down.

#3

image
not sure if this considered a max out of the CPU or not?
in any case - the ram isn’t maxed out, it goes only to about 70%
but the composition looks weird
image

the disk seems to be the only thing “maxed out” at 95-100% utilization.

#4

That’s the problem.

HDDs are a very high latency devices, so enumerating the files on the filesystem that involves touching metadata of many files is inherently slow. To address this, Linux caches frequently used filesystem data, including metadata, in the free available ram. This drastically improves filesystem performance.

You don’t have much ram there at all to start with (I recommend adding at least 8-16GB. It will make massive difference in your NAS performance even without duplicacy).

And then, when you ran duplicacy, it uses almost all available memory for itself, thus evicting filesystem caches. Now metadata is no longer cached and each file access is experiencing high IO latency, completely destroying performance.

#5

thanks for the explanation, makes a lot of sense
I did order a 16GB stick to add - I’ll report back here to see how much it improved things

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#6

can happily report an extra 16GB RAM stick improved speeds, and i’m now at a comfy 31MB/s

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