samba - Nov 2023 - understanding stat cache

On Fri, 10 Nov 2023 12:47:07 +0000
Ulrich Sibiller via samba <samba at lists.samba.org> wrote:
> Hello,
> 
> We have a user that switched from Linux to Windows with his
> engineering software. Previously he was using NFS to access data and
> there were no performance complaints.
> 
> Now, with Windows, the same procedures take minutes instead of
> seconds.
> 
> I created some log files in Samba 4.10.16-25.el7_9 (recompiled with
> gpfs support and using the gpfs vfs module) with debuglevel 10 to see
> if there's an obvious reason for the performance problems.
Without knowing how you are running Samba, it is a bit hard to comment,
but what I can say is, version 4.10.16 is ancient from the Samba point
of view, it is no longer supported directly by Samba. Perhaps trying a
much later version might help.
 
>
> 
> smb.conf has
>        max stat cache size = 512
That is the default on later versions of Samba.
> 
> (BTW: Is there some way to gather statistics about the stat cache?)
>
Not that I am aware, but others might.

Rowland

Rowland Penny wrote:
> Without knowing how you are running Samba, it is a bit hard to comment
What exactly would be of interest regarding "how I run Samba"? 
> , but what I can say is, version 4.10.16 is ancient from the Samba point of
view, it is no longer supported directly by Samba. Perhaps trying a much later
version might help.
Yeah, but it complicates things as 4.10.16 is the Redhat version. So I was
trying to avoid using another version. But I will see If I can make it run.
>> smb.conf has
>>       max stat cache size = 512
> That is the default on later versions of Samba.
And also on mine.

Uli