Recording HD to a network drive

[jonm]

I'm hoping to make my PVR PC diskless in the near future so I've been experimenting with recording to a network drive, with little success.

Is anyone else here successfully doing this, in particular, for a HD channel?

It looks like something in my setup can't keep up, as the picture and sound are all broken up on playback. I'm trying to work out where the bottleneck might be as I'm sure this ought to be possible... Any pointers gratefully received!

Jon.

[mathieumg]

Are you recording HD content? If so, are you using a Gbit network?

Else I doubt that 12.5 Megabytes per second is enough (or even if it is, it would have to be at peak speed at all times etc.)

It's even worse if you are on 802.11g (n might be ok, again depends on signal strength)

[jonm]

Yeah, it's Gbit. I'm not actually convinced the Vista PC (with GBPVR on it) is really connecting at 1Gb though, I think I need to copy a few files around to get some timings etc.

[ilovejedd]

I haven't tested it myself, but I've heard of several people who have it working just fine. Testing it right now.

Instead of a diskless PVR PC, have you considered consolidating file serving and PVR functions (even printer server) onto one computer? While GB-PVR's LiveTV on client mode leaves something to be desired, it works very nicely for recordings, even HD ones.

You don't need a gigabit network. Fast ethernet (100mbps, 12.5 MB/s) should suffice for most. OTA HD has a maximum bitrate of 19mbps (2.375 MB/s), well within the 100mbps envelope. Wireless is kinda finicky and that I would steer clear of if at all possible.

[ilovejedd]

Finished test recording 3 HD channels (CBS, CW, NBC) to unRAID server using gigabit with no problems.

GB-PVR server
Pentium Dual-Core E2160 1.8GHz
Kingston 2x1GB DDR2 667 SDRAM
Intel PRO/1000GT PCI NIC

unRAID server
Celeron 430
Kingston 2x1GB DDR2 667 SDRAM
onboard Realtek RTL8168 10/100/1000
Samsung Spinpoint F 1TB x1 parity
Samsung Spinpoint F 1TB x1 storage

Network Path
GB-PVR server -> HP ProCurve 1400-8G -> HP ProCurve 1400-8G -> unRAID server

There's parity calculations in unRAID but I reckon that's minimal since right now, I'm essentially using a single hard drive.

Test recording 3 HD channels to 100mbps network share in progress.

[jonm]

Interesting, thanks.

I can't get it to work, yet SD records and plays back just fine to/from my server though.

I just copied a 9Gb recording from the PVR to the server in 10 mins so surely there should be no issues with performance? Now that file is on the server it plays back just fine. So it's just recording HD that seems to struggle.

I'm a bit stumped!

[ilovejedd]

Ugh... The fast ethernet is a no go. While I'm sure it's fast enough for 3 simultaneous HD streams, the laptop's running XP Home and I can't seem to get around security permissions.

I just copied a 9Gb recording from the PVR to the server in 10 mins so surely there should be no issues with performance? Now that file is on the server it plays back just fine. So it's just recording HD that seems to struggle.

Lol, if you can copy 9GB over 10 minutes, wonder why it's struggling to copy the same over the span of an hour. What are the specs of your PC and what's your set-up like?

[jdg]

Yeah, it's Gbit. I'm not actually convinced the Vista PC (with GBPVR on it) is really connecting at 1Gb though, I think I need to copy a few files around to get some timings etc.

Vista throttles network traffic while playing multimedia. Check this support article for ways to adjust the throttling:

http://support.microsoft.com/kb/948066

[jonm]

Vista throttles network traffic while playing multimedia. Check this support article for ways to adjust the throttling:

http://support.microsoft.com/kb/948066

Hmm, thanks. The thing is, when I'm recording, I'm not playing multimedia. Does it still apply? (and how does it know?)

[jdg]

Hmm, thanks. The thing is, when I'm recording, I'm not playing multimedia. Does it still apply? (and how does it know?)

Vista runs a lot of services in the background. If you aren't running multimedia it shouldn't throttle, so that article was just a suggestion to look into.