On 11/15/11 23:40, Tim Cook wrote:
On Tue, Nov 15, 2011 at 5:17 PM, Andrew Gabriel <andrew.gabr...@oracle.com <mailto:andrew.gabr...@oracle.com>> wrote:

     On 11/15/11 23:05, Anatoly wrote:

        Good day,

        The speed of send/recv is around 30-60 MBytes/s for initial
        send and 17-25 MBytes/s for incremental. I have seen lots of
        setups with 1 disk to 100+ disks in pool. But the speed
        doesn't vary in any degree. As I understand 'zfs send' is a
        limiting factor. I did tests by sending to /dev/null. It
        worked out too slow and absolutely not scalable.
        None of cpu/memory/disk activity were in peak load, so there
        is of room for improvement.

        Is there any bug report or article that addresses this
        problem? Any workaround or solution?

        I found these guys have the same result - around 7 Mbytes/s
        for 'send' and 70 Mbytes for 'recv'.

    Well, if I do a zfs send/recv over 1Gbit ethernet from a 2 disk
    mirror, the send runs at almost 100Mbytes/sec, so it's pretty much
    limited by the ethernet.

    Since you have provided none of the diagnostic data you collected,
    it's difficult to guess what the limiting factor is for you.

-- Andrew Gabriel

So all the bugs have been fixed?

Probably not, but the OP's implication that zfs send has a specific rate limit in the range suggested is demonstrably untrue. So I don't know what's limiting the OP's send rate. (I could guess a few possibilities, but that's pointless without the data.)

I seem to recall people on this mailing list using mbuff to speed it up because it was so bursty and slow at one point. IE:

Yes, this idea originally came from me, having analyzed the send/receive traffic behavior in combination with network connection behavior. However, it's the receive side that's bursty around the TXG commits, not the send side, so that doesn't match the issue the OP is seeing. (The buffer sizes in that blog are not optimal, although any buffer at the receive side will make a significant improvement if the network bandwidth is same order of magnitude as the send/recv are capable of.)

Andrew Gabriel
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