Slow NFS

lu6fer · 31 March 2016 13:33

Hello,
I have some issues with HD playback. With mkv files the playback is slow and freezing 30s for 2s of playing.

My setup :
raspberry pi B+
OSMC up to date
No addons
fresh install
NAS (openmediavault)
NFS share
Mysql library share

I was suspected my network, so I run some tests.
With bonnie++ and mounted file system.
I tested with NFS and SMB share to compare.

It’s clear to me that NFS as a poor latency (16x smb latency).
Beside switching protocol, which i’m going to do, where this difference came from ?

Thanks for your help

lu6fer · 31 March 2016 13:34

I forget to add a sample of avconv info :
Stream #0.0(fre): Audio: ac3, 48000 Hz, 5.1, s16, 640 kb/s (default) Metadata: title : VFQ AC3 @640Kbps BPS : 640000 BPS-eng : 640000 DURATION : 02:16:57.216000000 DURATION-eng : 02:16:57.216000000 NUMBER_OF_FRAMES: 256788 NUMBER_OF_FRAMES-eng: 256788 NUMBER_OF_BYTES : 657377280 NUMBER_OF_BYTES-eng: 657377280 _STATISTICS_WRITING_APP: mkvmerge v8.8.0 ('Wind at my back') 64bit _STATISTICS_WRITING_APP-eng: mkvmerge v8.8.0 ('Wind at my back') 64bit _STATISTICS_WRITING_DATE_UTC: 2016-03-13 22:43:17 _STATISTICS_WRITING_DATE_UTC-eng: 2016-03-13 22:43:17 _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES Stream #0.1: Video: h264 (High), yuv420p, 1280x534, PAR 1:1 DAR 640:267, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default) Metadata: BPS : 5214805 BPS-eng : 5214805 DURATION : 02:04:37.512000000 DURATION-eng : 02:04:37.512000000 NUMBER_OF_FRAMES: 179280 NUMBER_OF_FRAMES-eng: 179280 NUMBER_OF_BYTES : 4874220954 NUMBER_OF_BYTES-eng: 4874220954 _STATISTICS_WRITING_APP: mkvmerge v8.8.0 ('Wind at my back') 64bit _STATISTICS_WRITING_APP-eng: mkvmerge v8.8.0 ('Wind at my back') 64bit _STATISTICS_WRITING_DATE_UTC: 2016-03-13 22:43:17 _STATISTICS_WRITING_DATE_UTC-eng: 2016-03-13 22:43:17 _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES

DBMandrake · 31 March 2016 13:40

I assume if you are testing NFS via Bonnie you must be using a Kernel mount in /etc/fstab, not Kodi’s built in NFS client ?

If so, post your fstab so we can see your mount options for NFS and SMB. (Hide any passwords of course)

lu6fer · 31 March 2016 13:58

Kodi use it’s own nfs.
But for test purpose, i used kernel nfs/smb :
Kodi conf:
NFS
moorea:/export/Films on /mnt/Films type nfs (rw,nosuid,nodev,noexec,relatime,vers=3,rsize=524288,wsize=524288,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=192.168.0.253,mountvers=3,mountport=41862,mountproto=udp,local_lock=none,addr=192.168.0.253,user)

SMB
//moorea/Films on /mnt/smb-films type cifs (rw,nosuid,nodev,noexec,relatime,vers=1.0,cache=strict,username=root,domain=MOOREA,uid=0,noforceuid,gid=0,noforcegid,addr=192.168.0.253,unix,posixpaths,serverino,mapposix,acl,rsize=1048576,wsize=65536,actimeo=1,user)

server conf :
NFS
/export/Films 192.168.0.0/24(rw,all_squash,insecure,no_subtree_check)

SMB
[Films] path = /media/ad38d53b-3b41-4020-be00-7aa25617bad7/Films/ guest ok = yes guest only = yes read only = no browseable = yes inherit acls = yes inherit permissions = yes ea support = no store dos attributes = no printable = no create mask = 0755 force create mode = 0644 directory mask = 0755 force directory mode = 0755 hide dot files = yes

DBMandrake · 31 March 2016 15:01

The Raspberry Pi 1 struggles with NFS over TCP, if you want to get the best performance on a Pi 1 I would actually use UDP.

Your rsize and wsize are also rather large, I would drop them to 8192 for UDP.

I would simplify your NFS line a lot, you have a lot of unnecessary stuff, try something similar to this:

moorea:/export/Films /mnt/Films type nfs vers=3,rsize=8192,wsize=8192,udp,retrans=2

NFS should be performing better than SMB, not much worse.

lu6fer · 31 March 2016 15:29

Thanks for your answer, I will try that today.
FYI : It’s not my fstab entry, but the resulat of mount -v to display all options in use

By the way, if the new test are correct, how to convert such conf to kodi. Because the target is kodi nuilt-in nfs mount.

DBMandrake · 31 March 2016 15:38

Ah, it would have been helpful to see the lines directly from fstab, not the output of mount -v…

If you want to stream high bitrate videos on a Pi 1 I would not recommend using Kodi’s built in NFS client, it has a number of shortcomings and will never perform as well as a kernel nfs mount. You’ll get at most about 25Mbps while playing video.

lu6fer · 31 March 2016 15:44

Here they are:
192.168.0.253:/export/Films /mnt/Films nfs user 0 0 //moorea/Films /mnt/smb-films cifs rw,user 0 0

Ok so I will test with kernel mount.
But If I remenber correctly, the share path is in mysql data, so all my shared library will be obsolete ?

DBMandrake · 31 March 2016 15:48

Ok try the mount line I suggested.

Cross that bridge if you get to it - lets see if the kernel mounts with the right options can improve the performance. As a test you can play some videos via Video->Files, browsing directly to the mount points in /mnt.

If necessary you can use path substitution to remap the paths so you don’t need to rescan the library, if you don’t fancy rescanning the whole library.

lu6fer · 31 March 2016 18:50

Test are not so conclusive for bonnie:

But the playback seems better.
I will try with other files to confirm

DBMandrake · 1 April 2016 09:39

Might be unrelated but it has just occurred that this may help, can you give it a try ?

lu6fer · 1 April 2016 09:54

I will try the conf,
But I do’nt have managed switch, only GBE standard swicth and GBE internet box.

For the library, I came to an other solution, drop database, replace nfs by local mount point and reinsert database.
It’s a small update to do, and don’t required full library rescan

Any way thanks, i will try this setup for a little time to ensure not issues appear .

DBMandrake · 1 April 2016 09:56

Sorry I mean just try the turbo option. For the user in that thread it helped him even on a switch with flow control enabled. (not sure why though)

lu6fer · 5 April 2016 09:02

After some test, the playback is find
I need to run other tests to check NFS speed on another system.
I will try bonnie on my archlinux to see if there is any difference.

I’ll keep you posted

popcornmix · 6 April 2016 12:24

If smsc95xx.turbo_mode=Y improves network playback, can you test with that option removed and smsc95xx.packetsize=4096 added instead?

We know turbo_mode causes issues in some heavy use cases (e.g. torrent downloading), so we’d like to find a safer alternative that still provides the network performance improvement.

You need to be on the April update for this option to be supported.