write big file using SMB freezes at 99%

[Nikotine]

Hi,

I've been experimenting with SMB2 vs NT1 and asynchronous I/O, sendfile and large read/write settings. I read/write a 3GB file.

I've noticed that whatever I choose, read speeds are fine (though less spikes with NT1), for example:


Write speed is tremendous, but it hangs for about 5 minutes at 99%!
You can see that it starts reading. It takes about 5 minutes to get from 99% to 100%!!
What's happening there?



I should probably say this file is read/written from a Windows 8 system. Oh, and I use ZFS Raidz1, three 2TB WD caviar reds.

[rostreich]

on win7 and win8 use definately smb2. AIO works since .636. sendfile on is ok.

large read/write settings

work with standard settings so far.

but regarding your other NIC problem, I'd say use Intel NIC.

[Nikotine]

Well, with SMB2, large I/O, asynchronous I/O, but without sendfile, because it can't be enabled with SMB2, I get this:


A lot more spiking, so I suppose NT1 is better, even with Win8.

But the problem is writing, it takes 5 times more time to get from 99 to 100% than it took to get to 99%

[raulfg3]

you don't say how much RAM do you have and if use ZFSkerntune.

I suggest to tune ZFS using ZFSkerntune in all cases, you see the difference.

PD: I asume that your problem is a ZFS tune problem.

[Nikotine]

I have 8 gb ram, but haven't used ZFSkerntune. I will try that.
So with that ZFSkerntune thing, I should be able to use SMB2 with large read/write, asynchronous I/O, without sendfile?

[raulfg3]

Yes

[Nikotine]

So I've been experimenting with samba settings after using the ZFS kernel tune script.

Using NT1, large read/write, asynchronous I/O, with sendfile:



Using SMB2, large read/write, asynchronous I/O, without sendfile:



All done with a 3GB file from a Windows 8 station.

There's a lot of variation in read speed when using SMB2. It goes over 100 mb/s, but the average speed seems to be slower than NT1. Using the ZFS kernel tune script or switching from NT1 to SMB2 didn't fix the 99% hang!

Is no one else experiencing this?

[Nikotine]

Anyone's got an idea?

[rostreich]

Not really.

I don't know if we talked already about trying from a win7 machine on other thread or pm. Do you have a laptop or could a friend bring his to your lan to just try it?

Maybe it could help to deactivate ipv6 on the win8 NICs properties.

[Nikotine]

Ok, so I bought an Intel Gigabit Pro 1000 CT and man, what a performance boost:


SMB2 - large read write - asynchronous I/O - NO sendfile

Both read and write speed average around 110 MB/s.
The 99% hang still exists, but at least it's a lot shorter.