RT-AC68U link aggregation with Synology DS220+/DS720+

[David Cavalli]

https://www.androidcentral.com/synology-2020-nas-ds220-plus-ds420-plus-ds720-plus-ds920-plus

I've never owned a NAS before and have had intermittent problems using an external HD connected to the USB3 port on my RT-AC68U. Synology has a new NAS that's exactly what I've been waiting for. One of the key features on the DS220+ that differentiates it from the DS218+ predecessor is the dual gigabit ethernet. From what I understand, my RT-AC68U router has the ability to do link aggregation and would work with the DS220+. If I get the concept right, that might not double my speed, but double the throughput and handle a quantity of requests from different sources better. (It's going to be my media server and backup unit.)

I've searched the threads in Merlin for "link aggregation" and found one with a different NAS unit connected, so I believe there's precedent and proof of concept for "how to". What I need to know before buying is that this CAN do link aggregation the way I think it should and that I could get forum help if I run into trouble.

I'm not worried about which NAS to buy brand-wise, and figure I'll buy the low end one of the 4 in that article, but all have the 2 ethernet ports so the question is the same for all.

Everyone always comments every time I post, so I'll say it proactively -- I have a legitimate RT-AC68U for years, not some 'clone' that is illegally flashed (whatever that means), and I am running the Merlin software on it. I can post the picture again if anyone needs to establish that fact in order to answer my questions.

Thanks in advance!

 

[ColinTaylor]

The RT-AC68U doesn't officially support link aggregation (even in Merlin). You can try the scripts from the wiki/forum but you're on your own really...

I doubt you'll see much improvement over a single gigabit link because of the CPU hit. But that's just a guess.

 

[L&LD]

How many devices will concurrently interact with the NAS? A two-drive bay unit is limited by the performance of the HDD's in use (and their RAID setup), not by the GB Ethernet connection. Will you be upgrading the RAM and using an SSD as a cache? That should help, but it will depend on your actual file sizes transferred on how effective they are to speed up concurrent connections for multiple clients.

A more reliable and effective solution is a four + drive unit with fast drives instead. The RAID type that is chosen, and the quality of the HDD's will be key to good performance and the second LAN port can be used in fail-over mode, more effectively (and more reliable too).

The take away here is that streaming and file backup needs rarely exceed the theoretical 113MB/s speeds of GB Ethernet. If you really need more, a 10GB NAS should be considered with more than 4 drive bays too.

 

[dosborne]

I wouldn't rush out and buy anything based on link aggregation. If you want the unit anyway, then sure, but I certainly wouldn't spend extra on upgrading it until you know it would make a difference.

I have 2x QNAP NAS units, both support link aggregation (port trunking). With my low end unit (TS-231P 2x4TB 1GB RAM), there was no real difference in performance. With my mid-grade unit (TS-563 5x10TB 16GB RAM), even with various upgrades, the performance still didn't really improve beyond standard.

It could be my use case is different from yours, but mine are essentially backup and media storage. I found that multi-homing the units (1xNIC on different subnets) was more useful in my scenario allowing limited access from the internet (web server for example) but keeping all other services isolated to the internal network.

It may also be worth upgrading to 10GbE if you really need more network throughput, but there are of course limitations there as well.

 

[David Cavalli]

Wow! Absolutely *NONE* of you said what I wanted to hear, but ultimately might be telling me what I need to hear. Now I'm thinking of switching to the DS920+ model, which does have dual ethernet, but has the higher bay space and a better processor. Thinking I go with 4 smaller drives which will amortize the higher platform cost and get me more space.

Link aggregation was a concern so glad I asked. NO need to be "on my own" or a trendsetter in the new frontier.

Thanks everyone!