[Samba] Hanging, uninterruptible smbd-process in "D"-state

[Rainer Krienke]

Hello,

I run a samba server for windows users who access their user data via 
samba. The samba server is NOT the domaincontroller. This task is 
performed by a native windows machine. The samba server is  running on a 
pve virtual machine. All data that samba delivers to the windows users 
are stored on two NFS servers (also VMs) and accessed via an automounted 
NFS mount for each user on the samba server. At most times of the day 
there are about 70-100 different users accessing this smb server.

The samba version is: samba-4.15.13+git.591.ab36624310c-150400.3.19.1 on 
a SuSE SLES15SP4 system.

This system worked flawless for years (of course using older versions of 
linux and samba) but since about a month  every now and then I have the 
problem that a windows user reports that her/his windows session is 
hanging or he/she gets only a black screen when loggin in  windows. In 
such a situation there always is a process of the user in question in 
the process state "D" on the smb server. The nfs-mount for this user on 
the smb-server is however available without problems.

Since the process is in state "D" its not killable and the only solution 
is a reboot of the samba server itself which of course is an "ugly" 
solution.

I cannot find anything special in the logs.

The samba.conf is included below.

Any ideas?

Thanks Rainer

------------------
smb.conf:
[global]
         workgroup = UNI
         server string = Samba %v
         log file = /var/log/samba/log.%m
         log level = 2 winbind:2
         max log size = 0
         unix extensions = no
         wide links = yes
         kernel oplocks = no
         oplocks = yes
         posix locking = no

         acl allow execute always = yes
         store dos attributes = no
         socket options = TCP_NODELAY SO_RCVBUF=524288 SO_SNDBUF=524288 
IPTOS_LOWDELAY

         max open files = 32808
         dead time = 15
         getwd cache = yes
         stat cache = yes
         browseable = no
         use sendfile = true
         aio read size = 32768
         aio write size = 32768

         disable netbios = yes
         smb ports = 445

         dos charset = CP850
         unix charset = CP850
         name resolve order = host wins bcast
         netbios name = unismb
         clustering = no
         passdb backend = tdbsam
         vfs objects = fileid

         realm = UNI.UNI-KOBLENZ.DE
         security = ADS
         winbind use default domain = no
         winbind max domain connections = 10
         winbind max clients = 1000
         winbind reconnect delay = 20
         map to guest = bad user
         min domain uid = 0

         idmap config UNIKO : backend = nss
         idmap config UNIKO : range = 0-2000000
         idmap config UNIKO : read only = yes
         idmap config * : backend = tdb
         idmap config * : range = 3000000-4000000
         idmap config * : read only = no

         map acl inherit = yes
         include = /etc/samba/smbshares.conf
-- 
Rainer Krienke, Uni Koblenz, IT-Services, A22, Universitaetsstrasse 1
56070 Koblenz, Tel: +49261287 1312 Fax +49261287 100 1312
Web: http://userpages.uni-koblenz.de/~krienke
PGP: http://userpages.uni-koblenz.de/~krienke/mypgp.html