samba - Jan 2018 - Samba 4.7.x IOWAIT / load average

Hi Jeremy,

What do you need exactly ?

Thanks
--
Christophe Yayon
> On 10 Jan 2018, at 01:38, Jeremy Allison <jra at samba.org> wrote:
> 
>> On Tue, Jan 09, 2018 at 03:27:17PM +0100, Christophe Yayon via samba
wrote:
>> Hi,
>> 
>> I want to report a strange problem with samba 4.7.x and IO wait / CPU
usage.
>> 
>> I am using linux (archlinux, kernel 4.14.2) and encounter a very
strange bug with only samba 4.7.x (from 4.7.0 to last 4.7.4).
>> With these versions CPU usage and IO WAIT is very high with a single
CIFS client with very low transfert (about 1MB/s).
>> 
>> I rollback to 4.6.9 to 4.6.12 and no problem with these versions.
> 
> More details/logs needed. Not enough info here to even begin
> to debug I'm afraid.

Hi,

I found the problem !
It was the params "strict sync" which is default to "Yes" on
4.7.x and "No" on 4.6.x and previous.

When i force to "strict sync = no" in my config file, no more abnormal
load average.

is this normal to default to "yes" on 4.7.x ?

Thanks

-- 
  Christophe Yayon
  cyayon at nbux.org

On Wed, Jan 10, 2018, at 07:11, Christophe Yayon via samba
wrote:
> Hi Jeremy,
> 
> What do you need exactly ?
> 
> Thanks
> --
> Christophe Yayon
> 
> > On 10 Jan 2018, at 01:38, Jeremy Allison <jra at samba.org>
wrote:
> > 
> >> On Tue, Jan 09, 2018 at 03:27:17PM +0100, Christophe Yayon via
samba wrote:
> >> Hi,
> >> 
> >> I want to report a strange problem with samba 4.7.x and IO wait /
CPU usage.
> >> 
> >> I am using linux (archlinux, kernel 4.14.2) and encounter a very
strange bug with only samba 4.7.x (from 4.7.0 to last 4.7.4).
> >> With these versions CPU usage and IO WAIT is very high with a
single CIFS client with very low transfert (about 1MB/s).
> >> 
> >> I rollback to 4.6.9 to 4.6.12 and no problem with these versions.
> > 
> > More details/logs needed. Not enough info here to even begin
> > to debug I'm afraid.
> 
> 
> -- 
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On Wed, Jan 10, 2018 at 11:20:30AM +0100, Christophe Yayon via samba
wrote:
> Hi,
> 
> I found the problem !
> It was the params "strict sync" which is default to
"Yes" on 4.7.x and "No" on 4.6.x and previous.
> 
> When i force to "strict sync = no" in my config file, no more
abnormal load average.
> 
> is this normal to default to "yes" on 4.7.x ?
Yes, it's a much safer option.