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The Graveyard - Products No Longer Supported => D-Link Storage => DNS-320 => Topic started by: padul on January 09, 2012, 08:44:39 AM

Title: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: padul on January 09, 2012, 08:44:39 AM
Hello all,

I purchased a DNS-320 from MediaMarkt recently with it in the following setup:

Firmware: 2.02 release (09/23/2011) - Reset to factory defaults after flashing
HD: 2 x WD20EARX-00PASB0
Mode: RAID0
Router: Cisco E4200
Laptops: Macbook Air (Lion), Macbook Pro (Lion), Lenovo X61S (Ubuntu 11.10)
Shares: AFS

Basically the problem I am having is that even with the Lenovo connected via Gigabit ethernet link, the write speed is max 11MB/sec.

I know these HD's are not on the offical list, but I did a bit of googling and found people with 25MB/sec speeds etc....

I find that the Mac's over wireless hit about 8MB/sec ... all very strange.

Could it be that the unit SATA controllers are faulty? Seems amazingly slow, too slow.

All the best
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: BlackBishop64 on January 09, 2012, 08:56:23 AM
Some guys reported bad performance after upgrading to 2.02, I will pay attention to your post because I really interested in this issue. Check http://forums.dlink.com/index.php?topic=42695.msg152201#msg152201

Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: JavaLawyer on January 09, 2012, 09:11:19 AM
Enable Jumbo frames, and experiment by disabling some other services you might be running (e.g. UPNP, AV Server, FTP Server, DHCP Server, etc.)
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: padul on January 09, 2012, 09:29:27 AM
Hi guys, many thanks for replying so quickly.

FYI: Any unneeded services have been disabled / off. So no P2P, FTP, etc, etc.

To enable jumboframes do I not have to have direct access to Linux via telnet or SSH to change the MTU?

Regards
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: padul on January 10, 2012, 12:59:09 PM
Just tested read speed on a 10GB file from NAS -> MacBook Air, was about 8MB/Sec..... what the hell is going on here?
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: Hanzo on January 12, 2012, 10:43:56 AM
i have a similar problem,

firmware 2.0
wd 20earx

via 100 Fethernet the write rate is 9,5MB/s

WTF!
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: padul on January 12, 2012, 11:37:13 PM
I think I might cut my losses and slap the whole unit on ebay and buy a decent NAS. Was an impulse purchase, won't be doing that again in a hurry.

Sorry to hear you also are not happy with the NAS :-(
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: albuemil on January 12, 2012, 11:42:46 PM
...via 100 Fethernet the write rate is 9,5MB/s...

If you're saying that you have a 100Mbps network connection to the NAS then the 9.5MB/s is a very good speed.
Don't forget, 100Mbps = 100/8 MB/s = 12.5 MB/s, but you won't get to 12.5 because of the packet headers and other data that needs to be transmitted.

On the other hand, if you're on a 1000Mbps (also called 1Gbps / gigabit connection) then the 9.5MB/s speed is indeed low since the theoretical maximum would be 125 MB/s.

I for one usually get about 15-20MB/s, sometimes lower (specially with a lot of small files), i also got 25-28MB/s when i transferred a lot of large files, but that's not the usual transfer speed i get.
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: saithan on January 14, 2012, 11:10:30 PM
Well, I've been able to figure out a lot more about my DNS 320, it's a big problem that there are no easier guides for first time buyers.

Anyway regarding the write speed, I have similar problem with that my connection with a cable enable me to get around 9,5mb/s and the wireless is on 2,08mb/s.

I checked my routers LAN setup and noticed that the LAN was set to 100M/Full Duplex, which means I should have more speed than I currently have.

But at the moment it's difficult to pinpoint why it's not going any faster.
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: baltzatu on January 17, 2012, 03:16:31 AM
@Saithan: Those values are normal for an 100Mb LAN connection and an 802.11g WLAN connection.

@Padul: Suggestion:
1. Install Debian Squeeze on NAS (you have the link)
2. Login into Debian and add a second IP address (ifconfig egiga0:0 192.168.222.125 netmask 255.255.255.0 - make sure you enter it without a gateway!)
3. Add a similar IP address to one of your computers connected to your router via LAN (let's say 192.168.222.126 - no gateway either!)
4. Access the NAS using the secondary IP and check the transfer rates.

It worked for me (in fact I had to do it, since I have a Gigabit switch and a 100Mb router).

Hope it helps :)

Edit: Before buying that Gigabit switch, I changed the HDD (had an WD7500AADS Caviar Green, bought a ST2000DL003 Barracuda LP Green). After the replacement, my transfer rates went up a little bit, so your HDDs might have something to do with the transfer speed...
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: FurryNutz on January 19, 2012, 12:45:42 PM
Any chance you can connect a external GB network switch between the 655 router and your devices and PCs? I highly recommend doing this as it will separate the NAS and Pcs from any router processing that is currently happening and will allow a more direct connection between the PCs and NAS.

I currently have a 655 router and right behind it is a 24pt Gb swtich and everything connected to that. Great speeds. Usually see about 40-60Mbs between PCs. Thats about what you should see after you connect a switch. Dlink has switches, I prefer HPs Pro Curve.

The problem your seeing is that the router is doing additional processing as thats its main function. This is pretty much inherent to any router. So if you separate that from the NAS and PCs, you'll see way better speeds and still connect to the Internet.

Let us know how it goes.
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: baltzatu on January 20, 2012, 12:38:12 AM
@FurryNutz: If the default gateway remains the same (DIR-655's IP), that separation is useless (I tried it, since my home network's topology contains a DIR-600 router and a DGS-1005D Gigabit switch). The best way to test the speed is the one mentioned before: put a second IP address on each device with no gateway nor DNS, access the device using the second IP, test the transfer speed.
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: BlackBishop64 on January 20, 2012, 12:48:55 AM
... The best way to test the speed is the one mentioned before: put a second IP address on ...

well, I think that the best way to check speed is DIRECT connection between PC and NAS. If you get bad results with direct connection nothing you do will improve it.
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: baltzatu on January 20, 2012, 04:49:58 AM
well, I think that the best way to check speed is DIRECT connection between PC and NAS. If you get bad results with direct connection nothing you do will improve it.
Even better :)
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: FurryNutz on January 20, 2012, 07:04:10 AM
Even better however the switch will work in this case too if you have PCs and NAS connected to the switch. Again this is for performance for file xfers between the PCs and NAS in this configuration. The switch will direct where the packets go with out any interference from the host router. Any packets sent thru the router will be effected by the router and thus will probably see reduction in performance. Also I presume that you have temporally turned off any 3rd party security SW on the PCs while testing too? This can effect performance as well.
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: padul on January 20, 2012, 08:39:08 AM
Hi, I thought I would update you on my personal situation. Well, firstly the DNS-320 is now unplugged and sat in a cupboard, minus the drives which are sat in a shinny new Core i5 box with FreeNAS 8.0 running on it. But, what is interesting is this.... I STILL had poor performance from my own custom box using AFP. So I looked in to it more.

Basically I've managed to narrow it down to AFP being VERY slow in general, however when using doing an FTP of a file to the FreeNAS I can hit up to 118MB/Sec, and reading at around 180MB/Sec. I have not so far tried to use CIFS but I will try it. Technically FTP has a lower overhead than CIFS/NFS/AFP.

I will be banging the DNS-320 on ebay and getting shot of it. Hopefully I can recoup some of the money I sadly spent on it.

All the best
Title: Re: Terrible write performance - Could the unit be bad, or is it the HD's?
Post by: ivan on January 21, 2012, 01:45:10 PM
Svenna, I have read your posts and am wondering why you have an obsession with high network speed.

If you are looking for pure speed then you will need to shell out big money to change your network to fibre, your computers to 6 core processors with SSDs and fibre NICs then any NAS you get will also require a high speed processor and SSDs as well as fibre NIC.

If, on the other hand, you have an ordinary network, like most people, then you need to look at all the factors that can give apparent slowness on that network.  Things like routers which are not switches and add overhead to anything that moves through them.  Then there is cabling which can pick up noise if improperly sited and so slow packets down.  Finally there are the computers themselves, most of the built in NICs are not the highest quality, unless you are running a server, and can vary considerably on same spec motherboards - in face we have one here that only manages half the speed of an identical MB.

The critical thing with any network is 'will it prevent you working because it is slow', if the answer is no then the network is doing its job.  If the answer is yes then you need to find the bottle neck and fix it.