Gigabit Link Aggregation / Jumbo Frames / NAS question

[occamsrazor]

Hi,

I just bought a QNAP TS-239 Pro II NAS, to be used with 2 x 2TB WD20EADS in a JBOD or Raid-0 setup, which hasn't arrived yet, but am already thinking how I need to optimise my home network to get the best out of it.

I'm thinking particularly about trying to use Jumbo frames and Link Aggregation, seeing as the unit has 2 ethernet ports. My current gear is:

Linux-flashed (Tomato firmware) 100mb Wifi-G Router

Netgear GS608 Gigabit switch (v1)
http://www.netgear.com/Products/Switches/DesktopSwitches/GS608.aspx?detail=Specifications

1 x Mac Mini with 100mb ethernet
1 x Mac Mini with Gigabit ethernet
1 x MacBookPro with Gigabit ethernet
1 x Linksys SPA-3102 VOIP adapter with 100mb ethernet
1 x QNAP TS-239 Pro II NAS with 2 x Gigabit ethernet ports

Main uses of the NAS will be downloading, Time Machine backups from all machines, streaming movies etc.

So my questions are:

1. Is there any point in me seeking to setup Link Aggregation? What real-world benefit am I likely to see? I should note that none of my machines have Dual-NICs themselves, apart from the NAS.

2. The GS608 doesn't specifically mention Link Aggregation or 802.3ad support (mine is also an older version than the link above). Does this mean I'll likely have to buy a new switch that specifically supports this? What would happen if I just plugged the two cables into a switch that didn't specifically support it? Or is it just the device that has to support it, not the switch?

3. Re: Jumbo frames, currently I don't use, but would like to. I can't tell if my current switch supports them as it is an older model. Does the switch have to support them? What if I buy a new switch that does support JF, but use it under a router that doesn't, would that be a problem?

4. My understanding was that for it to work, all machines on the network need to be set to use Jumbo frames. Given that I have devices that can't use Jumbo frames e.g. the Linksys VOIP adapter, does this make it impossible for me? What if I plugged those devices into the 100mb router, and saved the Gigabit switch only for Jumbo-frame-capable machines? Would that work?

4. Finally, if it does make sense, can anyone recommend a good switch that fulfils the following:

- 8 Ports
- Link Aggregation
- Jumbo Frames
- Preferably ports at the back of the unit, not front (this lives in my living room).
- Unmanaged I think - my router does QoS and bandwidth controls if needed, I don't see what real benefit a managed or smart switch would add to my particular situation.

I've been looking at a bunch such as this which seems quite nice:

http://www.asus.com/product.aspx?P_ID=eAFylicSHCzCucUS

..but don't see mention of Link Aggregation


Thanks in advance if you can help....

 

[thiggins]

To benefit from link aggregation, a NAS has to support sustained throughput > 125 MB/s. The TS-239 Pro II does not.

For more info, see Need To Know: Jumbo Frames in Small Networks

For link aggregation, you need a managed / "Smart" switch like this one Linksys SLM2008 8-port 10/100/1000 Gigabit Smart Switch Review

 

[occamsrazor]

Thanks Tim!

So no link aggregation needed, that simplifies everything greatly, thanks...

Re: Jumbo frames, I just found that Need-to-Know article before you replied, sorry I didn't see it earlier, I have read it now. Can you tell me if my understanding of the following is correct, If I were to have:

Gigabit switch WITH jumbo frames support, connected to:

A - Computer with Gigabit Jumbo frames enabled
B - Computer at 100mb no Jumbo frames
C - TS-239 Pro II with Gigabit Jumbo frames enabled

Would I be correct in saying that when doing a large transfer from Computer A to NAS C, I would NOT get the benefit of Jumbo frames?

From the Need-to-know I got the impression that to deal with the above mixed-speed machines, I need to physically separate the JF machines on a JF switch with no NON-JF machines on that switch, or create separate VLANs? Is that right?

 

[00Roush]

My take on it would be to shy away from using jumbo frames in mixed enviroments. I believe it is possible to have them on the same switch but problems can arise. So far I have not seen much difference using Jumbo frames with most modern computers as they are not CPU bound. But if any of your machines are underpowered (80-100% CPU usage during file transfers) Jumbo frames might increase performance a bit. You should be able to do some quick performance testing to see if they help or not.

So to clarify... yes you can have JF and NON JF computers connected to the same switch. If you are transferring data between two computers with JF enabled you should still see the benefits of JF. Problems usually arise when trying to communicate between JF and NON JF computers. But none of this is absolute. Sometimes it works sometimes it doesn't. As Jumbo Frames are NOT part of the ethernet standard it really comes down to how a particular vendor has implemented it.

00Roush

 

[occamsrazor]

Thank you very much for that clarification...

Problems usually arise when trying to communicate between JF and NON JF computers.

Just out of interest, how would those problems likely manifest themselves? Would the user be easily aware something wasn't working properly?

 

[thiggins]

Would I be correct in saying that when doing a large transfer from Computer A to NAS C, I would NOT get the benefit of Jumbo frames?

No. If the only two machines in the transfer are both jumbo frame enabled and connected via a jumbo-frame enabled switch, they should operate with jumbo frames.

It's when you have simultaneous transfers to both jumbo and non-jumbo machines that you can run into problems.

00Roush has good advice. I don't see any difference between jumbo and non-jumbo NAS Chart tests with my Core2 Duo test platform.

 

[occamsrazor]

Thanks to both of you.... I guess there's no point upgrading my switch then.

 

[Dawgneck]

Tag Question for Tim

Hi, Tim.

Since it appears the OP got his questions answered, let me tag a few....

I have a Qnap 809 with two ethernet connectors (capable of trunking/JF), an Asus P6T7 mobo with two ethernet connectors (capable of trunking/JF) and the Linksys 610N ver2 wifi switch (not capable of trunking/JF).

I am looking to replace my 610N ver 2 switch with a MANAGED switch that has trunking/JF & eight (or more) ports, possibly in the rear like the Linksys SLM2008 you mentioned earlier but isn't managed.

Can you suggest such a switch?

Lastly, is it possible to plug the 610N into a port (on whatever switch you recommend) and still us its wifi connection to connect a laptop to the network?

Thanks in advance for your reply.

 

[thiggins]

Dawgneck,

I use a NETGEAR GS108T.

Yes, you can uplink the new switch to the WRT610N.

 

[tipstir]

A lot of these newer routers allow you to connect more than one switch or AP with or without (router with switch ports) to the router. Uplink wasn't an issue anymore like in the old days. DIR-655, Belkin N+ ESR-9850, TEW-652BRP an etc.