[Samba] Very slow samba performance on Centos 6

[vg_ us]

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From: "Volker Lendecke" <Volker.Lendecke at SerNet.DE>
Sent: Thursday, August 04, 2011 11:01 AM
To: "vg_ us" <vg_us at hotmail.com>
Cc: <samba at lists.samba.org>
Subject: Re: [Samba] Very slow samba performance on Centos 6

> On Thu, Aug 04, 2011 at 10:49:50AM -0400, vg_ us wrote:
>> I have 2 identical Dell r510 servers with 10gig card, running centos
>> 6 with samba-3.5.4-68.el6_0.2.x86_64.
>> I setup 16G ramdisk samba share on both and ran cp from local
>> ramdisk to samba ramdisk mount.
>> If I cp 12 1-gig files, I get combined 100MB/s transfer rate. Single
>> file cp maxes out at about 15MB/s.
>> Ftp transfer give me over 300MB/s.
>>
>> Running with 9000 MTU. Most smb.conf is default. I even disabled
>> atime and tried ext2 and xfs on ramdisk.
>>
>> Any help will be greatly appreciated.
>
> What client application are you using? If it is a cifsfs
> kernel mount, you might see such artifacts. Please retry
> with the smbclient(1) application. If that is also slow, we
> need to investigate further.
>

I re-ran some of the tests with following result:

Ftp ramdisk-to-ramdisk:
13572 MB, 32.8 secs - 413.8 MB/s

Ftp ramdisk-to-hardisk:
13572 MB, 62.8 secs - 222.4 MB/s

Smbclient ramdisk-to-ramdisk:
13572 MB 40 secs - 339 MB/s

Smbclient ramdisk-to-harddisk:
13572 MB 64 secs - 212 MB/s

cifsfs mount ramdisk-to-ramdisk:
13572 MB 289.8 - 47MB/s

cifsfs mounts are really slow, so what happens when linux, windows and mac 
clients map/mount the share? Are they gonna be this slow? Any way to speed 
it up?

Thanks

- Vadim