Low performance and transfer interrupts

[Deaffy]

Hey guys!

I have an N5200B Pro with 2 Samsung F1 1TB Harddrives (HD103UJ, FW: 1AA0) in a RAID 0 configuration (Bays 0+1). The IP address is statically assigned to the WAN ports and I use a GigabitEthernet Switch in between the NAS and the rest of the network (mostly Windows SMB clients). Firmware is 2.00.04.

I am getting intermittent performance in such a way that file transfers seem to interrupt and hang for a few seconds, sometimes timing out the copying process totally on my Windows client. I use CIFS/SMB for file transfer.

I have not yet been able to pinpoint further whether this is an issue internal to the box (e.g. the Samba process having trouble wirting to the HDD or the SATA controller having problems with the drive) or whether this is an external networking problem. Iperf so far runs fine and shows the expected level of performance. The NAS is connected to a Gigabit Switch (Consumer, so not really sure about its performance). Jumbo frames are switched off on the N5200.

I see the transfer running, then it stops (HDD lights go off and vmstat also showing no more transfers). This goes on for a few seconds, sometimes it starts up again, sometimes the windows client times out and aborts the transfer. At the same time this occurs I also notice that I can't access the web interface and the browser also times out. I am using the same switch and ethernet port for both file transfer and web access, so this is not necessarily an indication that the NAS box itself is hanging, but might still be the network.

Does anyone have an idea on where i might look to find any further indication what causes the problem?
E.g. enable some more logging. I see that /var/log/lastlog is linked to /dev/null. Can I just remove that link and make a normal file to see some real logs?

On the Smart Info page (Storage -> Disks), the statistics look ok, except for the value in "Hardware ECC Recovered" which lists six digit numbers for both my drives. Can someone explain what this parameter means?

One thing makes me wonder: I had the HDDs installed in the lower two bays when i set the box up initially. The problem was much more prominent then (I ran the disks in a JBOD configuration at that time). When I moved the HDDs to the upper two bays, I opened the enclosure an make sure that the SATA backplane is fully pushed in and that the HDDs have proper connectivity. So maybe this is still some kind of low-level physical connectivity problem between the HDDs and the backplane. I also remember there was a similar thread about this especially with the Samsung drives that I use.

Would anyone have an idea how to enable low level logging to see whether some transfers fail on the SATA connection between the controller and the drive?

Thanks a lot,

Thomas

[Biddyman]

I just was basically asking the samething in my thread and I've seen others. Looks like it is a problem or we all have something set wrong.

[Deaffy]

I brought home a "proper" switch with more than enough performance. The problem still persists, so i suspect it is some problem internal to the NAS. I opened a ticket with Thecus support (also sent the config file just to be sure). Hopefully they can come up with a solution, otherwise I will have to return the product and the drives.

[Biddyman]

Let me know what you here from them. I may do a ticket too.

[Deaffy]

More interesting results. I made some measurement with iozone. When I run iozone on my Windows client on a share that I have mounted from the NAS, I can see the performance drops very clearly.

If I run iozone locally on the NAS, the performance is much more smooth and it doesn't seem to have any problems. To me this looks like the problem is more on the networking side of things. Either Samba not behaving properly, the ethernet driver having a problem, or a faulty network cable.

I'll switch the network cable when I get home and see if this gives me better results.

[Deaffy]

Changing the cabling did not help. I also used a different PC as a client to rule out any erratic behaviour of that installation.

So my conclusion is that it's a problem with the network interface/samba performance on the N5200B and I'll have to wait on the support staff to get back to me. So far no reaction from them, neither to my ticket nor in this thread as you can see.

Cheers,

Thomas

[Deaffy]

Hmm still no replies. Am I doing something wrong here?

[Russr]

Hi
I've just posted a thread where one half of it might be related. We've noticed that the N5200Pro occasionally drops offthe network. It has generally seemed to re-establish connection, though recently we had to cold-boot it to get it reconnected.

I'm wondering what it's status is on your network when these interruptins occur? Can you see it on the network? Can you access the Web Admin tool, or ping it?
Thanks
russ

[Deaffy]

If it drops the data rate, it is usually not reachable anymore via the web interface. It is like it's clogged up CPU-wise. There are no logs indicating that the network link has gone down, however.

Cheers,



Thomas

[Deaffy]

I have now decided to return the unit to the dealer, since it doesn't seem to me that there will be a solution forthcoming and I am not really willing to spend top-dollar for a pro-sumer solution and get less than optimal results.

Cheers,

Thomas

[Deaffy]

I am back in the game. I bought a new N5200B Pro and equipped it with 5 1TB Seagate Barracuda 7200.11 (ST310000340AS). Firmware is 2.00.10.

The problem, sadly, is back as well. Symptoms and findings are totally the same as with my earlier posts above. In the meantime, however, the network infrastructure is changed to a better switch and proper cabling, so I am very sure that the problem lies with the NAS.

Does anyone here use the same drives? Also my earlier questions about how to diagnose on the box where the problem is, still remains unanswered. Any help woulb be greatly appreciated.

Cheers,

Thomas

[Thecus - Yvon]

Dear Sir,

If possible, please prepare a single file about 100MB ~1000MB (we could via ZIP or RAR to create this singel file or from VIDEO file), and than via direct cable connection between PC & N5200, using FTP to verify each singel file wiriting performance from PC to N5200 for a basic testing.