Slow write speed when dling torrents, fast when transferring local network

[Method320]

I have a seedbox next to my nas in a rack. Seedbox runs rtorrent and plex in a VM. I have gigabit internet, and can saturate that with torrents from a private tracker to my desktop (though I typically see 70 to 80 MB/s) When downloading the same exact torrents from my seedbox with the download location pointing to my nas, speeds never go above 30 MB/s

Freenas box specs:
4x 2TB Seagate
64 GB ssd cache
12GB DDR3 ram
Xeon E5540

My question is why would this be happening? Is it a network issue? Something with freenas? Something with how I've mounted the share?

Not sure if worth noting but, I rebuilt my nas yesterday. It previously did not have an ssd cache. That drive used to be the boot drive, but I've since added more drives to expand the array, and I figured I'd rebuild the entire thing to see if that might help my speeds. Copying over all my data from my desktop to the nas went solidly and smoothly, at 112MB/s basically the entire 5 hours.

 

[c32767a]

I have a seedbox next to my nas in a rack. Seedbox runs rtorrent and plex in a VM. I have gigabit internet, and can saturate that with torrents from a private tracker to my desktop (though I typically see 70 to 80 MB/s) When downloading the same exact torrents from my seedbox with the download location pointing to my nas, speeds never go above 30 MB/s

Freenas box specs:
4x 2TB Seagate
64 GB ssd cache
12GB DDR3 ram
Xeon E5540

My question is why would this be happening? Is it a network issue? Something with freenas? Something with how I've mounted the share?

Not sure if worth noting but, I rebuilt my nas yesterday. It previously did not have an ssd cache. That drive used to be the boot drive, but I've since added more drives to expand the array, and I figured I'd rebuild the entire thing to see if that might help my speeds. Copying over all my data from my desktop to the nas went solidly and smoothly, at 112MB/s basically the entire 5 hours.

Need more info.. are you sharing between your seed box and nas using NFS? SMB? local disk on the VM? Something else?

Have you done all the basic connectivity performance tests between the two? Eg, read and write a file outside of your torrent client, raw network checks with iperf? do they all check out?

 

[tvsjr]

First, you don't have nearly enough memory to be adding an "SSD cache" (presumably, you're referring to an L2ARC). L2ARC adds memory pressure on the system... you can actually make things worse, not better. The usual guidance is to not even consider an L2ARC until you've maxed out the RAM on the motherboard, or at least reached 64GB (such as with a new E3 or an E5).

You need to break your problem down and work through it step by step. If you were able to copy your data from your desktop at gigabit speeds, then the problem isn't FreeNAS. You need to look at every step in the middle. First, if you have gigabit Internet, a single gigabit NIC, and you're trying to push the data somewhere else, you'll never see 100+MB/sec... you're pulling data from the Internet and immediately pushing it back out to a network device, so you're consuming network bandwidth in both directions. Your issue could be at the VM level, in the network path (maybe a crappy Realtek NIC?), etc.

 

[Method320]

Need more info.. are you sharing between your seed box and nas using NFS? SMB? local disk on the VM? Something else?

Have you done all the basic connectivity performance tests between the two? Eg, read and write a file outside of your torrent client, raw network checks with iperf? do they all check out?

Not sure how exactly to do those checks, I'll consult the google and report back. Sharing is done via NFS share

 

[Method320]

First, if you have gigabit Internet, a single gigabit NIC, and you're trying to push the data somewhere else, you'll never see 100+MB/sec... you're pulling data from the Internet and immediately pushing it back out to a network device, so you're consuming network bandwidth in both directions. Your issue could be at the VM level, in the network path (maybe a crappy Realtek NIC?), etc.

While it's true it'll go back down the same line, it's full duplex (and I've confirmed its running at full duplex) so that really shouldn't matter. I should still see theoretically 100 MB/s, or at the very least, much more than 30 MB/s.

I don't think the issue is vm level or a problem with the nic. It's on a dell R710, 4 gigabit intel nics.

 

[c32767a]

Not sure how exactly to do those checks, I'll consult the google and report back. Sharing is done via NFS share

You might also want to check out the posts on here referencing NFS performance as well. Your typical torrent will be many random IO reads. You might be just having issues with all the NFS iops. One quick and dirty thing you could do is try increasing the number of NFS servers that get started in the NFS configuration. You can probably go to 20 or 30 without any major negative impact.