I want to set up a new box for my SageTV server, so the hope is to move my recording directory to the UnRaid box. I plan to redo my wiring with Cat6a (it was cheap) and reduce the # of switches in the network. So I have been playing with maximizing my read/write/network performance before I actually move Sage to the new box. I was getting about 20MB/s reads when I started all of this, but I have seen over 70MB/s parity syncs so I expected more.

 

I was running a few tests with UnRaid and two windows boxes using Realtec chips and seeing a max of 29MB/s with bwm-ng. So I decided to try some Intel Pro 1000 Nics in the UnRaid box and the new SageTV box, leaving the Realtec enabled in the old SageTV box. I switched to TeraCopy and I got about 25MB/s on the Realtec box and 43MB/s on the new Sage box with the Intel NIC. The strange thing is that bwm-ng reports about half the speed of TeraCopy, not sure why. Using Jumbo frames on the Intel cards really kills performance, but seems to help on the Realtec chipset. I plan to redo the TeraCopy testing with the Realtec chipset and Jumbo frames enabled.

 

Any words of wisdom appreciated. I have been through the forum/FAQs, but I'm not seeing consistent results. I did notice that with the Intel NICs reads start out at about 60 MB/s and then drop back to 45 MB/s. This is obviously some sort of cache effect, which I would have expected less of since I have 8GBs of RAM in this box, as it was leftover from another project. I'm using a Cache drive for my writes and seeing around 23 MB/s, but I have not tried this with TeraCopy or the Intel NICs yet.

 

23-29 MB/s is a perfectly normal write speed into the parity protected array.  However, it is much too slow for a cache drive.  I routinely see 50-65 MB/s writes to my cache drive (an older 500 GB 7200 rpm WD w/ 8 mb cache).  My guess is that there might be something wrong with the drive itself, not your network.

 

Also, what size of files are you transferring?  Use files larger than 8 GBs if you really want to get realistic results.

The only advice I have is to move the recording from a local drive on your SageTV server to your unRAID server AFTER it has completely finished recording.  I've had too many power outages, switch or cable problems right in the middle of a recording to trust recording over the network no matter how reliable unRAID is.  This way I can verify the file after copying to make sure it got there correctly and can be copied when no recording are going on.  Ultimately I would like to figure out how to install the linux version of SageTV on unRAID but my linux skills are severly lacking.

23-29 MB/s is a perfectly normal write speed into the parity protected array.  However, it is much too slow for a cache drive.  I routinely see 50-65 MB/s writes to my cache drive (an older 500 GB 7200 rpm WD w/ 8 mb cache).  My guess is that there might be something wrong with the drive itself, not your network.

 

Also, what size of files are you transferring?  Use files larger than 8 GBs if you really want to get realistic results.

 

Yeah I expected around 60 writing to the Cache drive, no idea what the issue might be. The Cache drive sits on an Areca controller, so I'll have to look at that next. The syslog shows all drives started at SATA2.

 

File sizes I've been testing with (reads) range from 1 GB to 8GB.

The only advice I have is to move the recording from a local drive on your SageTV server to your unRAID server AFTER it has completely finished recording.  I've had too many power outages, switch or cable problems right in the middle of a recording to trust recording over the network no matter how reliable unRAID is.  This way I can verify the file after copying to make sure it got there correctly and can be copied when no recording are going on.  Ultimately I would like to figure out how to install the linux version of SageTV on unRAID but my linux skills are severly lacking.

 

Power here is a bit unstable too, especially during the summer. But pretty much the entire LAN is on a UPS of some form or other. I'd like to get the SageTV/UnRaid combo working, so when I get rid of my cable co, the switch over is relatively painless.

I have MANY UPSs myself (multiple systems) with switches, STBs, Tuners and PCs pluged into them.  I also have the switch and cable problems worked out so it probably would not be a problem to record across the network now.  But after all the problems I just don't trust recording directly to network storage.  Another reason I record local is so that if I want to add more storage to unRAID I don't have to wait to do that when no recordings are going on.

 

FYI - power:

When I first moved into my house my power would only go out in good weather.  If I had a storm of any kind no problem but let it be between 60 & 70 and sunny and wham!  Now I can't even trust bad weather.  When it is out for longer than a few seconds it is the WHOLE neighborhood so I know it isn't just the line to my house or house wiring.  I even had an outage between the time I parked the car in the garage and entering the house.  Don't think I loose power every day or week however.  It is only when I least want to have a power outage.  And always just long enough for the UPSs to shutdown the computers.  Although it was out for 9+ hours one time but usually just 20-40 minutes at a time 3-4 times a year.

 

 

Played with all variations of NICs, with and without a crossover cable. The Intel NICs made no difference, perhaps even slightly worse. The crossover cable had very slight gains, but not significant; a good thing I suppose. The best I saw on reads was about 45MB/s on average with spikes up to 62 MB/s or so. Reads from one drive are significantly slower than another, likely caused by fragmentation and file location on the disk. There are also two different controllers on the MB, so it's possible that one performs better than the other. I did not check which disk was on which controller, I assume the Syslog would tell me? Reads from a Share are slower of course. Still surprised that the reads are as slow as they are, since I know the LAN can do better. The drives also produce reads between 133 MB/s and 80 MB/s on a preclear.

 

I did switch my Cache drive to Raid0, so I'm seeing writes between 62 MB/s and 45 MB/s, so I expect an average around 50 or so. This s/b speedy enough for SageTv even with other network traffic, as long as I cap my SABNZBD downloads. :-) I'm only using the Cache for TV shows, so I'm not too worried about losing data. Other writes will go straight to disk.