N5200 slow read but fast write over windows network

[ccarey75]

Hi all - below is an email I sent to Thecus support on the 15th of November (no response yet - whee)

Short story is that we get really awful network performance out of our N5200 for read operations using windows file copy. Oddly enough write operations are speedy (the reverse of what I would expect). All is well over FTP in both directions so we have determined there is no issue with other network components.

If someone from Thecus support reads this could you reply to my original email please? It's been rather a while and this is our second attempt at getting answers on this issue.

The original email had the config bin attached

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email to thecus support:
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We have an N5200 which we're having some issues with. Generally it's well behaved but copying files over the network via the windows file system (ie just dragging files into folders) is really slow.

Copying a single 45MB file from the N5200 to my desktop takes around 60 seconds and gives me approximately 4 to 8% network utilisation (measured by windows task manager). By contrast copying the same 45MB file TO the N52000 (from my desktop) uses more like 80% of my bandwidth and takes around 5 seconds.

If I perform the same operations FTP I get around 10MB/sec in both directions (ie both read and write take around 5 seconds).

I've tried the operation with similar results on several different computers on my network, including:

• windows XP (10/100 nic)
• windows 2000 SBS server (gigabit nic)

Here are the things we've looked at and done to diagnose/fix the problem already:

• checked the RAID array (it's intact and healthy)
• upgraded firmware to the latest one (N5200upgrade.2.00.01.bin)
• enabled and disabled windows firewall (no difference)
• disabled all other applications including antivirus (no difference)
• Copying to and from a windows server on the same network is full speed. The NAS is connected to the same switch as the windows server.
• We've tried swapping the Ethernet cable with the one connected to the fast server (no difference)

We're out of ideas now. Could you tell me if this is a problem that can be fixed?

[Thecus - Yvon]

Daer Sir,

Sorry about missing your mail, please kindly provide the CONF.BIN for us analysis, from we configuration page: SYSTEM->CONFIG MGMT->DOWNLAOD.

Yvon.

[durango]

ccarey75 and Yvon,
I have the same exact problem!
I have N5200pro with 750b X 5 seagate drives.
I get 25 to 30MB write speed however the read speed is only 5 to 8MB /sec.
I ruled our windows vista and xp as it gives the same on both machines.
I also changed gigabit ports, but no use.
I think this is a bug in the firmware.
I also sent my conf gile to Thecus.
Hopefully they figure this out quickly. I went for this N5200 just for the amzing speed compared to
NV+ but now getting frustrated.

[ccarey75]

I've sent this again just now to support-at-thecus.com
config attached as requested.

[ccarey75]

Yvon - I haven't heard anything back on this. Could you confirm if you got my email with the config file attached? If not I'll send it again -- I really want to get this sorted out.

[Thecus - Yvon]

Dear Ccarey75,

If your email account is cxxxxy@fxxxxxxxxxxxxxxxxe.net or cxxxxt@fxxxxxxxxxxxxxxxxe.net , we found the File Access Cache is enabled, this function would enchance performance for PC reading small size file from N5200, this Please try to disable File Access Cache from NEWORK->SERVICE-> File Access Cache->DISABLE->APPLY than reboot N5220 and try.

Yvon.

[blueskyhost]

I believe I was engaged by ccarey75 in this context, and we seem to have hacked it with a satisfactory resolution, which we wanted to share with you.

The N5200 seems a little low on RAM as shipped with 256Mb and I suspect that the problem stems from this. Afterwards we tried shoving a 512Mb stick in there but I'm not entirely satisfied that that has made a difference.

In any case, the steps to follow are thus, and I would imagine that this would be useful for most users in general anyway, even with other models (at your own risk)...


1. You will need to install a bunch of additional modules. You can download all modules from here: N5200 Module List - Thecus Wiki (or check that site for modules appropriate for your model).

Upload them through your web control panel in this order:

SYSUSER - creates a user called "sys". Enable it and change the password through the configuration options.

SSHD - this gives you access to the NAS via SSH, using the sys user. Enable it, and download putty if necessary from here: PuTTY Download Page

IMGDUP - this hacks your firmware and links the file system to an editable image which is moved to your hard disk storage, where you can actually edit it.

Enable this through the control panel as well, by checking its box and clicking on the enable button.

So far, so good, this bunch of modules essentially gives you the ability to hack your system in many other ways that you may find useful in the future.


2. The problem we were having was resolved by editing smb.conf in /etc/samba. Unfortunately, or perhaps fortuitously, the filesystem is re-imaged every time you boot the device, hence the need for IMGDUP above.

But it seems that Samba is having buffering (and hence - I believe - RAM problems, which I'm not willing to expand on at this point, because I already read a lot of manuals today).

The trick was to edit the script that rebuilds the smb.conf file each time the device is booted. The answer was conveniently provided here: http://forums.hexus.net/thecus-care-...ing-samba.html

IMGDUP effectively backs up /img and then uses a symbolic link to point it to a location on your drive array, so you can effectively edit /img/bin/rc/assemble_conf using a tool such as vi (google "vi cheat sheet" if you need a quick introduction to vi).

Find the line that contains "socket options" by hitting the "/" key and typing "TCP" then enter.

Scroll to the end of the line and hit the "i" key to insert. Append data to make the line read as follows:

socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192

whereas it previously read:

socket options = TCP_NODELAY

Then hit Esc-w-q-Enter to save.

Restart your N5200 or compatible device.


smb.conf should now be built with these settings each time you boot. My understanding is that these are effectively fixed memory allocations for incoming and outgoing data. You could conceivably increase them in correctly calculated powers of 2. I'm not sure whether Samba is trying to use dynamic memory allocations, and this simply makes it more efficient, whether this reserves memory for these functions that is otherwise dominated by other processes, or whether it simply works better with Windoze. I spent over 6 hours on this today, and this worked for us, but we can't take responsibility if it doesn't work for you.

As one of my better friends always says: "blessed are the pessimists, for they make backups".

Comments welcomed.

Chris Bell
Computer Repairs | Geeks2U Same Day Onsite PC Repair Australia-wide
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[Thecus - Yvon]

Dear Sir,

Here we are glad about so many firends provide the module to enchance N5200 function, but also we need to ware of some module or related operation missing would make system malfunction and lost the warranty, thus before doing such operation or modification, please confirm we have enough ability to doing the operation.

Yvon.

[peterfu]

Yvon,
I think the possibility to enhance the product with modules - and many thanks to Thecus that such a possibility is supported - is one of the big advantages of the box. At least in my case it was one important decision point for purchasing the box, cause You can add missing functionality to the box.
br
Peter

[blueskyhost]

My understanding is that you can always "factory reset" if you break it. Not sure about the specifics of that - might involve a serial cable in the worst of examples, or just a firmware re-install in the simplest.

But I have also read stories of these boxes re-building RAID arrays of their own accord on odd occasions, which can potentially swipe your data, so best to have everything backed up first. It's worth spending a few hundred bucks on spare hard drives just to be safe.

Having said that, I don't think anything that I did was particularly invasive in terms of Thecus surgery. We modified the filesystem of the machine itself, but this had nothing to do with the drive arrays or the data contained thereupon.

If at any point I'd had any concerns I would have simply shut down and pulled the drives out. Conceivably, with a mirrored RAID array, you could pull out your mirrored drives while you do this just to be safe. I know I've done it with Windows servers before.

cb
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[blueskyhost]

Incidentally, that Socket Options line is embedded in a script, so my quote above in terms of how to modify that line of code doesn't include the quotation marks and the code that precedes it.

And I don't have access to the script right now in order to give you the full line of code, but as long as you replace what I've quoted as the previous string with the new string you should be fine.

Have I got enough posts yet to edit the qqq's in to www's in the above post?

cb
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[blueskyhost]

Dear Ccarey75,

Please try to disable File Access Cache from NEWORK->SERVICE-> File Access Cache->DISABLE->APPLY than reboot N5220 and try.

Yvon.

durango, are you willing to give this a try? didn't notice it before, but seems to be addressing a similar sort of issue.

cb
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[ccarey75]

Thanks for the suggestion, Yvon but since the modifications done by Chris Bell it's operating fast and with no discernable problems. I'm inclined to leave it "as is" unless we start experiencing problems.

I'd be curious if anyone does try Yvon's method - does it produce the same result?

[durango]

durango, are you willing to give this a try? didn't notice it before, but seems to be addressing a similar sort of issue.

cb
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I already have the file cache diable so this didn't colve the issue.
I will try your modification ans let you know.
Thanks
Durango

[blueskyhost]

Hi durango,

please let us know how you go, and feel free to ask for help. I'm subscribed to this thread.

Also if you could, could you please post the full line of code that needs to be modified as I don't have access to the NAS anymore.

cb
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[blueskyhost]

I now have 5 posts so updated the URLs in my original post.