Movies stutter when simultaneously writing to the same hard drive - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 14 Old 04-07-2013, 02:37 PM - Thread Starter
AVS Special Member
 
lockdown571's Avatar
 
Join Date: Nov 2005
Posts: 1,623
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 58
I noticed that I'll occasionally experience stuttering when watching a movie on Plex. I eventually discovered that this happens when large files are simultaneously being written to the same drive. For instance, I was watching a blu-ray today, and then the WHS add-in for WMC started transferring over a recorded TV show to the server, making the movie unwatchable. All videos are stored in a pooled Flexraid array on my WHS 2011 machine, mostly on WD Green HDDs.

Is there a better way to deal with this? I suppose I could just set up a different drive for recordings, but I like having everything on my Flexraid array. Is there a way to control which action gets priority? In this case, reading is much more important than writing. Or perhaps there's a way to have the WMC add-in only run late at night. Any ideas? Anyone else have this problem?
lockdown571 is online now  
Sponsored Links
Advertisement
 
post #2 of 14 Old 04-07-2013, 09:37 PM
Advanced Member
 
goros's Avatar
 
Join Date: Sep 2009
Posts: 778
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 33
This is where faster hdd speeds and sata6 connections can help a ton. If your processor isn't getting bogged down, That's the first thing I would look at. Green drives (or any 5400 drive) would not be my first choice for that use (simltaneously reading and writing files for long periods of time when performance is a must. If your processor is bottlenecking the performance, upgrading isn't hard. More RAM and using a ram cache can help too.

I'd also change the priority on your movie player to high or real time which may force windows to prioritize it, but if it's the disc physically being unable to keep up...you probably won't like the answer. (The answer is pick ONE task only).
goros is online now  
post #3 of 14 Old 04-08-2013, 03:42 AM
AVS Addicted Member
 
assassin's Avatar
 
Join Date: Jul 2004
Posts: 12,931
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Liked: 230
Hard drives can't even saturate sata3 so I am not sure how sata6 would help.

This seems like more of a network speed issue to me. I have done what you are doing countless times with no issue.
assassin is offline  
post #4 of 14 Old 04-08-2013, 04:19 AM
AVS Special Member
 
captain_video's Avatar
 
Join Date: Jan 2002
Location: Ellicott City, MD
Posts: 3,528
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Liked: 126
I'm wondering if there's an issue with parity being written at the same time everything else is going on. I've noticed that transfer rates to my unRAID server are many times slower than read rates for this very reason.

Reading and writing multiple files to the same drive simultaneously shouldn't be an issue, even with a 5400rpm drive. I frequently have six or more programs being recorded to a single drive simultaneously while playing back a 7th recorded show with absolutely no glitches.
captain_video is offline  
post #5 of 14 Old 04-08-2013, 06:11 AM
AVS Addicted Member
 
Mfusick's Avatar
 
Join Date: Aug 2002
Location: Western MA
Posts: 22,345
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 140 Post(s)
Liked: 760
Probably a combo or a poor performing HDD and two very large bandwidth hungry files.

Test your HDD speed. Post results.
Test your Netwirk speed. Post results.

We can then help determine and fix real issue.

-

"Too much is almost enough. Anything in life worth doing is worth overdoing. Moderation is for cowards."
Mfusick is online now  
post #6 of 14 Old 04-08-2013, 08:58 AM - Thread Starter
AVS Special Member
 
lockdown571's Avatar
 
Join Date: Nov 2005
Posts: 1,623
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 58
I use snapshot which updates early in the morning, so parity isn't being written. I've never had issues with getting gigabit speeds on my network, although maybe it could be a NIC issue with the server. What's the best way to test my hard drive and network speeds?

Processor on server is quad core q8400. 4 GB ram.
lockdown571 is online now  
post #7 of 14 Old 04-08-2013, 10:20 AM
AVS Special Member
 
Dark_Slayer's Avatar
 
Join Date: May 2012
Posts: 2,419
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
Liked: 273
I've had this issue when reading from a drive that's being written to

Never dug into it

I'd say you were onto something with the "priority"

Anyone who's never experienced the issue, simply copy a file (>1 GB) across your network and rename it (monitor your speed, probably between 80~100 MB/s)

Now, copy again (while monitoring the speed) but quickly grab the renamed one and copy it back (before the operation ends) to the original location (writing both directions). In my experience the speed is reduced drastically (not the expected linear 2x operations on the same network reduction, but instead the speed was around 25 MB/s or less each way)
Dark_Slayer is offline  
post #8 of 14 Old 04-08-2013, 10:24 AM
AVS Addicted Member
 
Mfusick's Avatar
 
Join Date: Aug 2002
Location: Western MA
Posts: 22,345
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 140 Post(s)
Liked: 760
A full green drive will drop in performance down to 60mb sec.

Writing in both direction to same drive is probably only 15mb sec average.

Your closing in on territory where it could be an issue

-

"Too much is almost enough. Anything in life worth doing is worth overdoing. Moderation is for cowards."
Mfusick is online now  
post #9 of 14 Old 04-08-2013, 02:25 PM - Thread Starter
AVS Special Member
 
lockdown571's Avatar
 
Join Date: Nov 2005
Posts: 1,623
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 58
80 MB/s from server to HTPC. When transferring large files both ways it plummets to 22 MB/s. That still should be plenty for blu-ray streaming though. Maybe the issue has something to do with the WHS add-in for WMC. I noticed that it does seem to take an unreasonably long time to transfer a recording over.
lockdown571 is online now  
post #10 of 14 Old 04-08-2013, 02:40 PM
AVS Special Member
 
Dark_Slayer's Avatar
 
Join Date: May 2012
Posts: 2,419
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
Liked: 273
Quote:
Originally Posted by lockdown571 View Post

80 MB/s from server to HTPC. When transferring large files both ways it plummets to 22 MB/s. That still should be plenty for blu-ray streaming though.

More than enough, blu ray only needs 5 MB/s. That isn't to say that within the Plex Server to Plex Client chain you aren't experiencing a few dips below the minimum requirement

Coming from someone who experienced a big WAF hit for rebuilding their flexraid parity, I would try everything to minimize any outage.

That being said, are you running flexraid with "folder split priority"?
Dark_Slayer is offline  
post #11 of 14 Old 04-08-2013, 02:49 PM - Thread Starter
AVS Special Member
 
lockdown571's Avatar
 
Join Date: Nov 2005
Posts: 1,623
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 58
Quote:
Originally Posted by Dark_Slayer View Post

More than enough, blu ray only needs 5 MB/s. That isn't to say that within the Plex Server to Plex Client chain you aren't experiencing a few dips below the minimum requirement

Coming from someone who experienced a big WAF hit for rebuilding their flexraid parity, I would try everything to minimize any outage.

That being said, are you running flexraid with "folder split priority"?

It's on "auto-folder-priority' if that's what you're asking.
lockdown571 is online now  
post #12 of 14 Old 04-08-2013, 02:56 PM
AVS Special Member
 
Dark_Slayer's Avatar
 
Join Date: May 2012
Posts: 2,419
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
Liked: 273
Quote:
Originally Posted by lockdown571 View Post

It's on "auto-folder-priority' if that's what you're asking.

Yes, I guess I was thinking you could re-arrange your data so that the recordings are isolated on a disk with plenty of space left. Then restart you pool / rebuild your parity frown.gif I couldn't bring myself to say it at first, because it would be quite the last resort for me.

Can you specify the schedule for the service on your clients for something like 3:30 am?
Dark_Slayer is offline  
post #13 of 14 Old 04-08-2013, 03:24 PM - Thread Starter
AVS Special Member
 
lockdown571's Avatar
 
Join Date: Nov 2005
Posts: 1,623
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 58
Quote:
Originally Posted by Dark_Slayer View Post

Yes, I guess I was thinking you could re-arrange your data so that the recordings are isolated on a disk with plenty of space left. Then restart you pool / rebuild your parity frown.gif I couldn't bring myself to say it at first, because it would be quite the last resort for me.

Can you specify the schedule for the service on your clients for something like 3:30 am?

That's what I was thinking. Just have the WMC service run sometime in the morning. I'm not sure how to do that though. Might be possible through task scheduler.
lockdown571 is online now  
post #14 of 14 Old 04-08-2013, 03:36 PM
AVS Special Member
 
Dark_Slayer's Avatar
 
Join Date: May 2012
Posts: 2,419
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
Liked: 273
Quote:
Originally Posted by lockdown571 View Post

That's what I was thinking. Just have the WMC service run sometime in the morning. I'm not sure how to do that though. Might be possible through task scheduler.

Yeah, I'm not running this (or even a WHS), but I'd start by perusing the services manager for something like
Quote:
Microsoft.HomeServer.Archive.TransferService.exe
as mentioned during some other troubleshooting steps over at the green button. After you know which service it is, scheduling it should be straightforward
Dark_Slayer is offline  
Reply Home Theater Computers

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off