samba - May 2019 - FW: Weird Samba/CIFS behavior: client hangs

Oeps, forgot the list. 

> -----Oorspronkelijk bericht-----
> Van: L.P.H. van Belle 
> Verzonden: woensdag 22 mei 2019 16:01
> Aan: 'sambalist at discosucks.it'
> Onderwerp: RE: [Samba] Weird Samba/CIFS behavior: client hangs
> 
> Try FQDN in the shares and not \\servername\ that might help. 
> Most simple to test. 
> 
> And OS? 
> Samba version? 
> Smb.conf? 
> Might help also. 
> 
> 
> 
> Greetz, 
> 
> Louis
> 
> 
>  
> 
> > -----Oorspronkelijk bericht-----
> > Van: samba [mailto:samba-bounces at lists.samba.org] Namens 
> > sambalist--- via samba
> > Verzonden: woensdag 22 mei 2019 13:10
> > Aan: samba at lists.samba.org
> > Onderwerp: [Samba] Weird Samba/CIFS behavior: client hangs
> > 
> > Hi there!
> > 
> > I have a very weird behavior in samba. I have been using a 
> > samba server
> > for sharing a folder to a cifs mount client for many years. 
> Since last
> > update, everything still works fine, but when i open a 
> photo subfolder
> > with a specific software (gwenview) and try to load thumbnails, the
> > whole mount stops responding.
> > 
> > On the client, i have the "server not responding after 120
seconds"
> > message. On the server, i can't see anything weird on the logs.
> > 
> > Restarting the server solves brings the client back to life 
> > (after a few
> > seconds), then it hangs again after loading 15-20 thumbs.
> > 
> > I have checked disks and network and found no problems. 
> > Access to files
> > is very fast, as long as i access: by example, i can md5sum all the
> > files in that folder and get a very good throughput. The 
> problem seems
> > to appear only when that software is loading thumbs.
> > 
> > My mount in fstab is:
> > //server/Dati /mnt/dati cifs
> > rw,nouser,auto,credentials=/etc/samba/credentials,iocharset=ut
> > f8,soft,_netdev,comment=systemd.automount,user_xattr,file_mode
> > =0600,dir_mode=0700,vers=1.0
> > 0 0
> > 
> > Maybe something related to opening many files at once? Any ideas?
> > 
> > Thanks
> > 
> > Gabriele
> > 
> > -- 
> > GPG Key Fingerprint:
> > DAD1 E3E3 C3E9 36FB C570 F405 9B5F 7108 A1D0 2FFF
> > 
> > -- 
> > To unsubscribe from this list go to the following URL and read the
> > instructions:  https://lists.samba.org/mailman/options/samba
> > 
> > 
>

I've tried straight the IP into the share \\x.y.z.k\, same behaviour.

The server is smbd 4.7.6 on Ubuntu 18.04.
The client is cifs-utils 6.8.2, samba-common 4.10.0 on Ubuntu 19.04

What i get on dmesg is
[ 1395.187394] CIFS VFS: Server x.y.z.k has not responded in 120
seconds. Reconnecting...

Server's smb.conf:
[global]

unix extensions = yes
case sensitive = auto
delete readonly = yes
ea support = yes
load printers = no
printcap name = /dev/null
disable spoolss = yes
invalid users = root
socket options = TCP_NODELAY
hosts allow = <my subnets>
unix charset = UTF-8
mangled names = no
workgroup = WORKGROUP
dns proxy = no

log file = /var/log/samba/mainlog
log level = 2
max log size = 10000

security = user
server role = standalone server

passdb backend = tdbsam
encrypt passwords = true
obey pam restrictions = yes
unix password sync = no
passwd program = /usr/bin/passwd %u
passwd chat = *Enter\snew\s*\spassword:* %n\n
*Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .
pam password change = yes

map to guest = bad user
usershare allow guests = no

[Dati]
   comment = Dati
   writable = yes
   path = /home/dati
   browseable = yes
   read only = no
   guest ok = no
   create mask = 0640
   directory mask = 0750

Thanks for your reply,

Gabriele

GPG Key Fingerprint:
DAD1 E3E3 C3E9 36FB C570 F405 9B5F 7108 A1D0 2FFF

Il 22/05/19 16:01, L.P.H. van Belle via samba ha
scritto:
> Oeps, forgot the list. 
> 
> 
>> -----Oorspronkelijk bericht-----
>> Van: L.P.H. van Belle 
>> Verzonden: woensdag 22 mei 2019 16:01
>> Aan: 'sambalist at discosucks.it'
>> Onderwerp: RE: [Samba] Weird Samba/CIFS behavior: client hangs
>>
>> Try FQDN in the shares and not \\servername\ that might help. 
>> Most simple to test. 
>>
>> And OS? 
>> Samba version? 
>> Smb.conf? 
>> Might help also. 
>>
>>
>>
>> Greetz, 
>>
>> Louis
>>
>>
>>  
>>
>>> -----Oorspronkelijk bericht-----
>>> Van: samba [mailto:samba-bounces at lists.samba.org] Namens 
>>> sambalist--- via samba
>>> Verzonden: woensdag 22 mei 2019 13:10
>>> Aan: samba at lists.samba.org
>>> Onderwerp: [Samba] Weird Samba/CIFS behavior: client hangs
>>>
>>> Hi there!
>>>
>>> I have a very weird behavior in samba. I have been using a 
>>> samba server
>>> for sharing a folder to a cifs mount client for many years. 
>> Since last
>>> update, everything still works fine, but when i open a 
>> photo subfolder
>>> with a specific software (gwenview) and try to load thumbnails, the
>>> whole mount stops responding.
>>>
>>> On the client, i have the "server not responding after 120
seconds"
>>> message. On the server, i can't see anything weird on the logs.
>>>
>>> Restarting the server solves brings the client back to life 
>>> (after a few
>>> seconds), then it hangs again after loading 15-20 thumbs.
>>>
>>> I have checked disks and network and found no problems. 
>>> Access to files
>>> is very fast, as long as i access: by example, i can md5sum all the
>>> files in that folder and get a very good throughput. The 
>> problem seems
>>> to appear only when that software is loading thumbs.
>>>
>>> My mount in fstab is:
>>> //server/Dati /mnt/dati cifs
>>> rw,nouser,auto,credentials=/etc/samba/credentials,iocharset=ut
>>> f8,soft,_netdev,comment=systemd.automount,user_xattr,file_mode
>>> =0600,dir_mode=0700,vers=1.0
>>> 0 0
>>>
>>> Maybe something related to opening many files at once? Any ideas?
>>>
>>> Thanks
>>>
>>> Gabriele
>>>
>>> -- 
>>> GPG Key Fingerprint:
>>> DAD1 E3E3 C3E9 36FB C570 F405 9B5F 7108 A1D0 2FFF
>>>
>>> -- 
>>> To unsubscribe from this list go to the following URL and read the
>>> instructions:  https://lists.samba.org/mailman/options/samba
>>>
>>>
>>
> 
>

On 24/05/2019 10:18, sambalist--- via samba wrote:
> I've tried straight the IP into the share \\x.y.z.k\, same behaviour.
>
> The server is smbd 4.7.6 on Ubuntu 18.04.
> The client is cifs-utils 6.8.2, samba-common 4.10.0 on Ubuntu 19.04
>
> What i get on dmesg is
> [ 1395.187394] CIFS VFS: Server x.y.z.k has not responded in 120
> seconds. Reconnecting...
>
I wonder if you are running into this kernel bug:

https://bugzilla.kernel.org/show_bug.cgi?id=198349

Rowland

I think a network trace would tell us for use whether the server is
responding or not.

You can follow the instruction here to make one:

https://wiki.samba.org/index.php/Bug_Reporting#cifs.ko

-- 
Aurélien Aptel / SUSE Labs Samba Team
GPG: 1839 CB5F 9F5B FB9B AA97  8C99 03C8 A49B 521B D5D3
SUSE Linux GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg)