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

[Rowland Penny]

On 01/02/2023 09:18, Rainer Krienke via samba wrote:
> 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.

It sounds like that you are mounting data via NFS and then re-sharing 
this via Samba. If this is the case, then this has never been a good idea.

> 
> 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

Why are you using 'fileid' ? I thought this was meant for a clustered 
setup and you have explicitly set 'clustering = no' (even though it is 
the default).

> 
>          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

Possible typo here, above it says the workgroup is 'UNI', but the 'idmap 
config' lines use 'UNIKO', which is it ? They should match.


>          idmap config * : backend = tdb
>          idmap config * : range = 3000000-4000000
>          idmap config * : read only = no
> 
>          map acl inherit = yes
>          include = /etc/samba/smbshares.conf

It might help to see the shares, you also may get more in the logs if 
you raise the loglevel.

Rowland