Mac Mini Server Link aggregation - Thunderbolt or USB 3 gigabit ethernet adaptors

Discussion in 'Mac OS X Server, Xserve, and Networking' started by gavcooper, Jan 15, 2013.

  1. macrumors newbie

    Jan 15, 2013
    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
    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.
  2. macrumors 6502a

    Oct 2, 2008
    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.
  3. thread starter macrumors newbie

    Jan 15, 2013
    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.
  4. ytk
    macrumors regular

    Jul 8, 2010
    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
  5. thread starter macrumors newbie

    Jan 15, 2013
    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?
  6. macrumors newbie

    Jan 9, 2013
    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)
  7. macrumors newbie

    Jan 9, 2013
    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
  8. thread starter macrumors newbie

    Jan 15, 2013
    I will have 4 users accessing the server at the same time, file sharing off the Pegasus RAID.
  9. Umac-de, Jan 17, 2013
    Last edited: Jan 17, 2013

    macrumors newbie

    Jan 9, 2013
    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).
    It is connection based and the connection is as it happens, random and fixed!
    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!
  10. thread starter macrumors newbie

    Jan 15, 2013
  11. macrumors newbie

    Jan 9, 2013
    For 5:
    Netgear GS108T-200
  12. macrumors regular

    Mar 27, 2005
    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.
  13. macrumors newbie

    Sep 24, 2010
    Los Angeles, CA
    What did you end up doing?

    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.

  14. thread starter macrumors newbie

    Jan 15, 2013
    Covalt, I did not use link aggregation in the end. Setup works nice a quick over a single gigabit connection.
  15. macrumors newbie

    Sep 24, 2010
    Los Angeles, CA

    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!
  16. macrumors newbie

    Mar 22, 2012
  17. macrumors 6502a

    Aug 27, 2013
    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
  18. macrumors newbie

    Mar 24, 2012
    So is RAID even necessary without LACP switch?

    Very interesting thread. Im was planing a similar setup as gavcooper and cobalt, but after sketching it on a piece of paper I notice the bottle neck being GBe from the server to the switch. I just bought a switch yesterday without LACP so my question is this: Is it necessary with a thunderbolt 2 raid (with lets say ~300MB/s read/write speed) for file share, when GBe can only transfer ~125MB/s from the server to the switch (if LACP is not available)?

    In my calculation, I might as well just get a 4GB TB-HD with a ~125MB/s read/write instead of an expensive RAID system.

    Any thought?
  19. macrumors regular

    Jan 14, 2003
    I'm trying to use link aggregation with a Mac Pro (has 2 built-in ethernet ports) and 2 managed switches we got: Cisco SG200-26.

    The link aggregation is configured on both the switch and the Mac Pro's OS X Network pane.

    All end users use a single gigabit connection, but I thought this would help when more people are accessing the eSATA hard drive that the Mac Pro hosts, since it can read/write around 260MB/sec.

    Is there any real way to make sure that this is working without setting up a link aggregation on another computer? I'm thinking terminal commands or something...
  20. macrumors 65816


    Apr 29, 2011
    Look at post #7 on this thread. I had a similar setup between 2 NAS units and only noticed a small change, possible due to connection overheads, but no real improvement in overall data rates. In the end I dismantled the setup as not being worth the aggro (extra cables, extra switch ports in use, complex setup sequences when changing ports etc)
  21. macrumors 6502a

    Aug 27, 2013
    you can screen share two client computers and transfer a file and look at speeds that way.
  22. macrumors 68020

    May 20, 2011
    I use the built-in ethernet for management and purchased 2 USB 3.0 Gigabit adapters and linked them together. My file transfer speeds have almost doubled (190%) from a single link. This is also based on the fact I have some SSD's mixed in.

Share This Page