Readahead for HD Video Playback CIFS/NFS/FTP over Wi-Fi

[gchirtoaca]

Hi,

I've tried your tools on my TV (the one from the sig.) because this is the biggest issue that I have, the lag with the full HD movies.
Unfortunately, it works a bit worse than my current setup, which is samba share on NAS and the smb/cifs client from the SamyGo extensions on TV.
The interruptions are bigger and some files which usually work are now rejected.
Tested it with an ftp server on PC (IIS) and also a ftp server running on the router/NAS (proftpd).
Tried with cable and also wireless with little difference.

I have a wirless B/G router and the Samsung wireless N dongle.
The speed between NAS and PC on cable is around 3000 KBytes/s on a Samba v3.5 share and 3200 KBytes/s on FTP.
Monitoring the speed on the router gives a top of 7.5 MBits/s. That works OK for 720p files, but not for 10 MBit/s 1080p files.

Thanks anyway for your work, wannaseek.
If I can give more feedback in order to solve this, I would be happy to.

[erdem_ua]

Read ahead is for fixing "spikes" bottleneck, not for solving average bandwidth requirement that higher than actual link speed. You can use gigabit connection to your Wifi 802.11n router/AP (it needed to support gigabit connection too as your computer ethernet port) with 801.11n wifi usb dongle. That will give higher bandwidth than 100Mb/s (~250MB/s) if router is close to you TV. (if they are in same room)... Or use some flash disk that speedy, 64GB memory to watch those high bandwidth movies...

[wannaseek]

Thanks for trying my tool!

In the meantime I have made some changes in my setup that allowed me to achieve 17 Mbits/s with G wifi (in the same room). Those were:
- check whether your neighbors are not using the same wifi channel as you do: http://www.geekzone.co.nz/inquisitor/2996
- I have bought a NAS with preconfigured NFS server, so I have switched to NFS. (the performance of curlFTP is probably not the best)

I will upload here the latest version of the tool and the init script soon.

[wannaseek]

The latest version is attached.

It does a readahead over nfs. But you can change the following line in the 05_05_readahead.init file to do readahead over smb, etc.

Code: Select all

SOURCE_DIR=/dtv/usb/nfs

[gchirtoaca]

Thanks a lot! I will try it tomorrow.
Update:
It works better! Thanks!
If I press pause for a few seconds, enough for the cache to fill, the video runs much smoother than the regular Samba.
Still, my bottleneck must be somewhere between USB HDD->Router->Network, because I get around 20 Mbs transfer speed, but is probably not a sustained speed.

Anyway, this is a progress! Thank you.

[wannaseek]

I have recognized that around 17 MBit/sec, the CPU consumption of the readahead tool becomes the bottleneck, it is around 40%-50% and by that the control buttons (ffwd, rwd, pause) become unresponsive. It stays like that even if I actually turn off the background readahead, even the "plain" read through fuse+readahead tool consums that much. It could have at least 3 reasons:
- fuse is slow. The readahead logic could be moved into a VFS implementation as kernel module instead of FUSE.
- readahead tool. It is not that much code, so it is unlikely that it comsumes that much. Maybe bad compiling options?
- double caching. the OS does caching on the readahead filesystem and on the nfs filesystem as well. I tried to switch it off with the direct_io flag but did not help.

So that is it. Any idea is welcome.

[wannaseek]

Maybe somebody is interested in doing the stackable file system (VFS) kernel module implementation for some compensation:
http://www.vWorker.com/RentACoder/misc/BidRequests/ShowBidRequest.asp?lngBidRequestId=1449414

[manga00]

Hello @ all

Know anyone a litle progamm called Netio, i used it to investigate the real network speed
for TCP and UDP transfer with variable Blocksize.
You can this software as Server and Client start.
In my network have i stable tranfers by TCP and Block 32768 K.

for example over AVM WlanStick 54Mbit Fritzbox 7270 Laptop and DS 207+
you can see at the values, wich mountoption has best the performance for you.
I used it for NFS connection with 100Mbit Networkcard.

I have this proggi for windows and linux for my DS.
Can anyone it compile for our Sammy, it is opend Source.


Website
Download

Code: Select all

NETIO - Network Throughput Benchmark, Version 1.26
(C) 1997-2005 Kai Uwe Rommel

TCP connection established.
Packet size  1k bytes:  1638 KByte/s Tx,  2084 KByte/s Rx.
Packet size  2k bytes:  1764 KByte/s Tx,  2127 KByte/s Rx.
Packet size  4k bytes:  1857 KByte/s Tx,  2086 KByte/s Rx.
Packet size  8k bytes:  1867 KByte/s Tx,  1052 KByte/s Rx.
Packet size 16k bytes:  1917 KByte/s Tx,  1133 KByte/s Rx.
Packet size 32k bytes:  2026 KByte/s Tx,  1954 KByte/s Rx.
Done.

D:\Downloads\netio126\bin>win32-i386.exe -u 192.168.100.150

NETIO - Network Throughput Benchmark, Version 1.26
(C) 1997-2005 Kai Uwe Rommel

UDP connection established.
Packet size  1k bytes:  1922 KByte/s (0%) Tx,  1110 KByte/s (91%) Rx.
Packet size  2k bytes:  1965 KByte/s (0%) Tx,  4423 Byte/s (99%) Rx.
Packet size  4k bytes:  2330 KByte/s (0%) Tx,  0 Byte/s (100%) Rx.
Packet size  8k bytes:  2499 KByte/s (0%) Tx,  0 Byte/s (100%) Rx.
Packet size 16k bytes:  2477 KByte/s (0%) Tx,  0 Byte/s (100%) Rx.
Packet size 32k bytes:  2387 KByte/s (0%) Tx,  0 Byte/s (100%) Rx.
Done.


Code: Select all

NETIO - Network Throughput Benchmark, Version 1.26
(C) 1997-2005 Kai Uwe Rommel

Usage: netio [options] [<server>]

  -s            run server side of benchmark (otherwise run client)
  -b <size>[k]  use this block size (otherwise run with 1,2,4,8,16 and 32k)

  -t            use TCP protocol for benchmark
  -u            use UDP protocol for benchmark
  -h <addr>     bind TCP and UDP servers to this local host address/name only
                (default is to bind to all local addresses)
  -p <port>     bind TCP and UDP servers to this port (default is 18767)

  -n            use NetBIOS protocol for benchmark
  -m <name>     use this as the local NetBIOS name (defaults are NETIOSRV
                for the server and NETIOCLT for the client)
  -a <adapter>  use this NetBIOS adapter (default is 0)

  <server>      If TCP or UDP is used for the client, a server name or address
                is required. For NetBIOS, this is optional, for the case that
                the server uses a different NetBIOS name than NETIOSRV.

The server side can run either NetBIOS (-n), TCP (-t) or UDP (-u) protocol
or all three (default, if neither -t, -u or -n are specified). The client
runs one of these protocols only (-t, -u or -n must be specified).

The -m and -a options apply to both client and server sides.


best regards

[mattberlin]

Hey guys,

updating to N Wifi gave me about 2 to 2.5 MB/s instead of 1.5 as I had it with G. This still isn't enough for many HD movies, so that I installed a nfs server on my Windows PC. It works fine.
The funny thing is that Rewinding and Fast Forwarding works pretty badly. This is even the case with movies that do not exceed 1.5 MB/s. If this is the case RWD and FF works better via Samba.
Do you guys have an idea why this works so poorly with NFS, since the performance via nfs is definitly better?

[erdem_ua]

Is could be problem on your WINDOWS instead of NFS?