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View Full Version : Mac Mini Server Link aggregation - Thunderbolt or USB 3 gigabit ethernet adaptors




gavcooper
Jan 15, 2013, 11:06 AM
I am setting up a late 2012 Mac Mini as a file server with Server 2.2. It has a Promise Pegasus R4 RAID and LaCie 4TB drives daisy chained via the thunderbolt connection. 4 users on MacPro's will connect to the server to access these hard drives via gigabit ethernet.

I imagine the gigabit ethernet will be the bottleneck, so I'm now looking at link aggregation. Not a problem on the MacPro's but the Mac Mini will require an adaptor to get a second gigabit port. From reading this forum I understand the Apple Thunderbolt to Gigabit adaptor will work, but I'm concerned that it will need to be fitted 3rd in line after the R4 and LaCie drives. The 10Gbps bandwidth Thunderbolt has, may cause another bottleneck with all three working off the same port?

An option would be to use one of the USB 3 ports with this adaptor http://www.ebuyer.com/412005-startech-usb-3-0-to-gigabit-ethernet-nic-network-adapter-usb31000s?utm_source=google&utm_medium=products
I believe it work with OSX, but I have no speed information or if OSX link aggregation will work using it.

Any thoughts on the above would be appreciated and recommendations on a suitable Network Switch with LACP support welcome.



hchung
Jan 16, 2013, 02:51 PM
I am setting up a late 2012 Mac Mini as a file server with Server 2.2. It has a Promise Pegasus R4 RAID and LaCie 4TB drives daisy chained via the thunderbolt connection. 4 users on MacPro's will connect to the server to access these hard drives via gigabit ethernet.

I imagine the gigabit ethernet will be the bottleneck, so I'm now looking at link aggregation. Not a problem on the MacPro's but the Mac Mini will require an adaptor to get a second gigabit port. From reading this forum I understand the Apple Thunderbolt to Gigabit adaptor will work, but I'm concerned that it will need to be fitted 3rd in line after the R4 and LaCie drives. The 10Gbps bandwidth Thunderbolt has, may cause another bottleneck with all three working off the same port?

An option would be to use one of the USB 3 ports with this adaptor http://www.ebuyer.com/412005-startech-usb-3-0-to-gigabit-ethernet-nic-network-adapter-usb31000s?utm_source=google&utm_medium=products
I believe it work with OSX, but I have no speed information or if OSX link aggregation will work using it.

Any thoughts on the above would be appreciated and recommendations on a suitable Network Switch with LACP support welcome.

I've never used link aggregation before, but it'll work with any adapter as long as the adapter works because it's independent of the adapter driver.

That said, it probably doesn't matter too much whether you pick the USB or TB gigabit adapter because two gigE ports won't be able to pull enough data off the TB drives to hit a bottleneck on TB. Your bottleneck is still the network.

gavcooper
Jan 17, 2013, 02:02 AM
Thank for the reply, hchung

The safest option would be the Apple Thunderbolt GigE adaptor as the drivers are probably built into OSX. The StarTech USB 3 adaptor would require its own driver which could cause problems.

Without trying it I can't see if two external RAID hard drives + the GigE adaptor will experience a performance issue.

Can anyone advise on the best way to measure the speed of a network? So I can see if LACP improves on our current single gigabit connection.

ytk
Jan 17, 2013, 03:42 AM
Generate a 1GB file of random data with

dd if=/dev/random of=bigfile bs=1048576 count=1024

Then see how long it takes to copy it over the network with each type of connection:

time cp bigfile /path/to/network/share

gavcooper
Jan 17, 2013, 05:17 AM
Thanks ytk, I have tested current single gigE connection to the Pegasus Thunderbolt RAID connected to the Mac Mini Server.

These are the figures:

real 0m11.212s
user 0m0.002s
sys 0m3.924s

Not sure if these are good figures for a gigabit connection, and if LACP will improve on this. Looks to me just under 100Mb/s, would that be correct for a 1000Mb/s connection?

Umac-de
Jan 17, 2013, 09:11 AM
Not sure if these are good figures for a gigabit connection, and if LACP will improve on this. Looks to me just under 100Mb/s, would that be correct for a 1000Mb/s connection?

You only have a 1GBit/s connection, not 1 GB/s :)
So 1000 GBit / 8 = 125 MB (theoretical max)

And LACP cannot improve on this, because LACP can only user based load balancing (not data based)

Umac-de
Jan 17, 2013, 09:25 AM
We have had a test on this with 3 MacPro:

Test 1
2x 6,95 GB files -> Server -> Bond(en0) -> Switch -> GigaBit -> MacPro1
13,9 GB in 2:06 = ca. 113MB/s

Test 2
2x 6,95 GB files -> Server -> Bond(en1) -> Switch -> Bond -> MacPro2
13,9 GB in 2:09 = ca. 110MB/s

Test 3 (at the same time)
6,95 GB file -> Server -> Bond(en0) -> Switch -> GigaBit -> MacPro1
6,95 GB file -> Server -> Bond(en1) -> Switch -> Bond -> MacPro2
13,9 GB in 1:19 = ca. 174MB/s

LACP works connection/user based - no improvement in test 2

gavcooper
Jan 17, 2013, 09:26 AM
You only have a 1GBit/s connection, not 1 GB/s :)
So 1000 GBit / 8 = 125 MB (theoretical max)

And LACP cannot improve on this, because LACP can only user based load balancing (not data based)

I will have 4 users accessing the server at the same time, file sharing off the Pegasus RAID.

Umac-de
Jan 17, 2013, 09:54 AM
I will have 4 users accessing the server at the same time, file sharing off the Pegasus RAID.

Ok, then you will have 2 on one ethernet port an 2 on the other of the server...
You only need a bond connection from the server to your switch and LACP activated on the switch with round-robin
(else it is only fall back).
But:
It is connection based and the connection is as it happens, random and fixed!
So:
User A on en0, user B on en0,
user C on en1, user D on en1.

If only A + B are pulling files from the server, none of them can use en1!

gavcooper
Jan 17, 2013, 09:59 AM
Okay, thanks for your replies

Umac-de
Jan 17, 2013, 10:27 AM
Any thoughts on the above would be appreciated and recommendations on a suitable Network Switch with LACP support welcome.

For 5:
Netgear GS108T-200

mus0r
Jan 23, 2013, 08:20 AM
For what it's worth, I have yet to have a compatibility problem with USB to ethernet dongles on Mac. Of the 3 or 4 I've tried on my own and others' Macs, they all worked and only one required me to find a driver.

Had the same results with eSATA cards on my Mac Pro. I think people sell Apple short in terms on hardware compatibility.

covalt
Dec 26, 2013, 05:05 PM
I am setting up a late 2012 Mac Mini as a file server with Server 2.2. It has a Promise Pegasus R4 RAID and LaCie 4TB drives daisy chained via the thunderbolt connection. 4 users on MacPro's will connect to the server to access these hard drives via gigabit ethernet.


I'm setting up a very similar server and am curious what you ended up doing and how it's working?
I'll be running my server (2012 Mac Mini) and all client machines on 10.9 Mavericks.
I'm leaning towards just getting Apple's thunderbolt to ethernet adapter. Then realized, with the Mini only having 1 thunderbolt port, I'd have to plug the ethernet adapter into the extra port on my external RAID drive. I assume this won't cause any issues, but curious if you're doing the same thing.

Thanks!

gavcooper
Dec 27, 2013, 04:06 AM
Covalt, I did not use link aggregation in the end. Setup works nice a quick over a single gigabit connection.

covalt
Dec 27, 2013, 04:29 PM
ah okay - thanks for letting me know.
I think I'm going to try link agg. with the thunderbolt to ethernet adapter and see if I get better performance.
Thanks again!

soundman414
Jan 2, 2014, 11:07 PM
You might also want to check out a few other options like TB to 10Gbe adapters and get yourself a switch with a 10Gbe link on it. It would eliminate the bottleneck of even multiple users accessing multiple volumes.

Here is one example:

http://www.sonnettech.com/product/echoexpressse_10gbeadapter.html

mvmanolov
Feb 5, 2014, 12:02 PM
So, i am a networking noob :) but i like playing around and having fun so here is what i want to know, if someone would be kind enough to explain:

If i have a MM server running a LACP bond to a managed switch through to another MBP also in a LACP bond (both having ssd's) would the file transfer between the two machines not equal 200+MB/s rather than the 100MB/s of a single link?

If so why not?

Thanks :D