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The Graveyard - Products No Longer Supported => D-Link Storage => DNS-343 => Topic started by: azz710 on March 09, 2009, 01:30:33 PM

Title: File management extremely slow. File deletes take inordinately long.
Post by: azz710 on March 09, 2009, 01:30:33 PM
Folks,

Can anyone suggest a reason that my DNS-343 (wired to a D-Link gigabit switch, in turn wired to a D-Link DIR-855 gigabit router, in turn wired to the gigabit NIC in my system) takes up to a minute to delete a file?

I find that if I select, say, 20 files in Windows Explorer (64-bit Vista SP1), hit delete and confirm the delete request, it can tale a half hour to complete.  This is causing my image program problems when it tries to manage its retention policy.

Regards,
Jeff

Title: Re: File management extremely slow. File deletes take inordinately long.
Post by: ECF on March 10, 2009, 09:39:24 AM
Have you tried to access the DNS-343 from another PC and do the same operation? Or remove the switch from your network and Try again?
Title: Re: File management extremely slow. File deletes take inordinately long.
Post by: azz710 on March 10, 2009, 11:52:46 AM
Dear ECF,

Thanks for the response.  I have tried from another PC (or three) and deletion is slow from all of them.  But I will, indeed, try connecting the D-Link DGS-2205 switch's input cable directly to the DNS-343 and see what happens.  When I do, I'll report back.

Meanwhile, I might be laboring under a misconception, but I thought that, in the absence of interference (and, in this case, the other three devices connected to the switch were idle), store-and-forward switches were nearly transparent.  Still, I'll check it, as you say.

Thanks,
Jeff


Have you tried to access the DNS-343 from another PC and do the same operation? Or remove the switch from your network and Try again?
Title: Re: File management extremely slow. File deletes take inordinately long.
Post by: netman1969 on July 04, 2009, 06:05:03 PM
Azz710,

Perhaps I can help a little here. For the record, store-and-forward is less transparent than say a standard cut-through. Store-and-Forward does just as the name implies and stores the entire frame in memory and makes a forwarding decision (based on the mac address) once the data has been integrity checked. A cut-through (traditional layer 2 switch) simply receives the packet header only and using the mac address it forwards the actual data on to the appropriate port. All that said, in your case, the error correction function of the switch is pretty much irrelevant since very little actual data is moving between the two devices in a delete function.

First I would look at your architecture. It sounds as though your PC is going through the router to get to the switch, which in turn has your NAS connected to it. I would suggest putting all of your network devices directly on the switch and connecting your router to the switch as well. This way all of your "access" layer devices are logically and physically located as close as possible on the network. By doing this, when your PC tries to access your NAS, the only logical decision being made is which switch port it needs to be forwarded to, and physically it stays within the same switching device.

As you have it today, the data travels to the router first. The router has much more overhead than a switch. It has to make decisions on routing, switching, protocols, QOS, etc. Then it will finally move it along to the switch when has to make the further decision of where to forward it to. The same happens in reverse, and with Windows even a simple delete command can generate quite a bit of back and forth communication between the two devices. We're talking potentially hundreds of back and forth messages for a simple delete.

Anyother consideration is Jumbo Frames. If you have it enabled on the NAS, you should have support for it throughout the path, including the PC.
 
Dear ECF,

Thanks for the response.  I have tried from another PC (or three) and deletion is slow from all of them.  But I will, indeed, try connecting the D-Link DGS-2205 switch's input cable directly to the DNS-343 and see what happens.  When I do, I'll report back.

Meanwhile, I might be laboring under a misconception, but I thought that, in the absence of interference (and, in this case, the other three devices connected to the switch were idle), store-and-forward switches were nearly transparent.  Still, I'll check it, as you say.

Thanks,
Jeff