Speeds capped about 1MB/s when running on a VM
Posted: April 7th, 2024, 6:36 pm
Lately I haven't been able to seem to get downloads much above 1MB/s, at least on instances running on a VM.
I can't say with perfect certainty, but I'm pretty sure this wasn't always the case. I moved from bare metal to a VM relatively recently and I don't recall seeing a performance drop like this when I first set it up or I would have investigated more then. Details about my setup:
* Sabnzbd 4.2.3 running in a container from linuxserver
* Host OS is Arch Linux, recently updated
* Hypervisor is XCP-NG 8.3
* i5 8500t, 4 cores and 16GB RAM allocated to the VM
Wrench results:
Used cache
4.1 MB (6 articles)
System load
0.21 | 0.21 | 0.27 | V=153M R=102M
System performance (Pystone)
389271 Intel(R) Core(TM) i5-8500T CPU @ 2.10GHz AVX2
Download folder speed
102.9 MB/s /incomplete-downloads
Complete folder speed
102.8 MB/s /downloads
Internet Bandwidth
31.4 MB/s 251.2 Mbps
It's not my ISP or router (I don't think) because if I spin up sabnzbd in a container on docker desktop on my workstation I can pull about the 30MB/s that I would expect from my connection.
It doesn't seem to be the disk since a) the wrench reports much faster folder speed than I can download and b) if I spin up another instance of the container without the mounts I get the same speeds.
I have another VM running basically the same stack on another host, and it can get about 12MB/s under the same (as far as I can tell) conditions. Which is definitely a lot better but still about half what I'd expect. If I could get the other one up to 12 I'd be pretty happy but I have no idea what to change to get it there.
Neither VM has dynamic memory, it's fully allocated in each case.
I tried rolling back to an earlier version of Sabnzbd with no luck. I've also tried nzbget and had the same results, so I recognize this isn't directly an sabznbd issue, but it's also so specific to this use case that I'm not sure where else to turn for troubleshooting ideas.
The speed cap is consistent whether it's one of the test nzbs from the wrench icon or a more traditional release. Any ideas what I should check next?
I can't say with perfect certainty, but I'm pretty sure this wasn't always the case. I moved from bare metal to a VM relatively recently and I don't recall seeing a performance drop like this when I first set it up or I would have investigated more then. Details about my setup:
* Sabnzbd 4.2.3 running in a container from linuxserver
* Host OS is Arch Linux, recently updated
* Hypervisor is XCP-NG 8.3
* i5 8500t, 4 cores and 16GB RAM allocated to the VM
Wrench results:
Used cache
4.1 MB (6 articles)
System load
0.21 | 0.21 | 0.27 | V=153M R=102M
System performance (Pystone)
389271 Intel(R) Core(TM) i5-8500T CPU @ 2.10GHz AVX2
Download folder speed
102.9 MB/s /incomplete-downloads
Complete folder speed
102.8 MB/s /downloads
Internet Bandwidth
31.4 MB/s 251.2 Mbps
It's not my ISP or router (I don't think) because if I spin up sabnzbd in a container on docker desktop on my workstation I can pull about the 30MB/s that I would expect from my connection.
It doesn't seem to be the disk since a) the wrench reports much faster folder speed than I can download and b) if I spin up another instance of the container without the mounts I get the same speeds.
I have another VM running basically the same stack on another host, and it can get about 12MB/s under the same (as far as I can tell) conditions. Which is definitely a lot better but still about half what I'd expect. If I could get the other one up to 12 I'd be pretty happy but I have no idea what to change to get it there.
Neither VM has dynamic memory, it's fully allocated in each case.
I tried rolling back to an earlier version of Sabnzbd with no luck. I've also tried nzbget and had the same results, so I recognize this isn't directly an sabznbd issue, but it's also so specific to this use case that I'm not sure where else to turn for troubleshooting ideas.
The speed cap is consistent whether it's one of the test nzbs from the wrench icon or a more traditional release. Any ideas what I should check next?