New install, smbd sits at 20-25% CPU all the time

KarstenV · April 19, 2017, 7:12pm

Having had to reinstall Rockstor today, I have run into a new problem I havent seen before.

The SMBD process (Samba) is constantly using 20-25% of my CPU.

This is not due to file accesses or anything like that, the system is completely idle, but the CPU is pretty busy.
I have never seen this behaviour in any of my earlier installs.

Anybody have an idea as to what could be the cause?

The problem persist across reboots. Switching of Samba in Rockstor fixes the problem, but its not a usable solution

Otherwise the system seems fine, I can access files both through SMBD and NFS.

Edit:

I just tried deleting my Samba shares. Even with no shares active, SMBD is still consuming ~20% CPU.

KarstenV · April 26, 2017, 1:49pm

Trying to bump this.

Does anybody have an idea?

Its a completely new install. Imported pools and shares, and setup Samba and NFS, and smbd is constantly using about 20% CPU, while the system is basically sitting idle.

The system otherwise works fine.

There must be a fix for this…

chicago · April 27, 2017, 8:10pm

I have this problem as well. It has persisted throughout releases. SMBD just hogs 20-40% CPU at all times. Even idle.

I thought it had to do with the kswapd kernel thread locking up and spewing errors into dmesg. But once I turned off kswapd entirely and no longer use swap at all, my kswapd lockups ceased.

But the SMBD CPU usage continued.

Fredrik · April 28, 2017, 4:45pm

I have samba and it’s not taking any CPU. Almost idle.
So do not think it’s a general issue.
Think more information is needed like your smb.conf and digging around in the logs if you find smb reporting any issues.

Flyer · April 28, 2017, 8:10pm

Hi @KarstenV,
on “Rockstor land” samba is my best friend and my coolest enemy too, so let’s have fun!

Can you provide you /etc/samba/smb.conf?
Can you describe your samba use? (ex. having rsync over cifs mounts? having tons of I/O via samba shares? etc etc)
Finally, can you provide some samba logs from /var/log/ ?

Mirko

KarstenV · April 28, 2017, 8:46pm

I will try to do my best.

Understand that this is a basic Rockstor install, and that I have only added the same shares I have had in all my other installs. Nothing is speicial, only CPU usage is high.

I dont run rsync (hardly know what it is), and my share access is mostly one file at a time, as Samba is mostly used for media access (playing movies and music).
The server is in no way under pressure, there are (at most) 3 clients accesing it, and 90+% of the time its sitting more or less idle (even then SMBD uses 20+% CPU).

smb.conf:

[global]
workgroup = SAMBA
security = user

passdb backend = tdbsam

printing = cups
printcap name = cups
load printers = yes
cups options = raw

[homes]
comment = Home Directories
valid users = %S, %D%w%S
browseable = No
read only = No
inherit acls = Yes

[printers]
comment = All Printers
path = /var/tmp
printable = Yes
create mask = 0600
browseable = No

[print$]
comment = Printer Drivers
path = /var/lib/samba/drivers
write list = root
create mask = 0664
directory mask = 0775
####BEGIN: Rockstor SAMBA CONFIG####
[Media]
root preexec = "/opt/rockstor/bin/mnt-share Media"
root preexec close = yes
comment = Media
path = /mnt2/Media
browseable = yes
read only = no
guest ok = no
admin users = Karsten
[Musik]
root preexec = "/opt/rockstor/bin/mnt-share Musik"
root preexec close = yes
comment = Musik
path = /mnt2/Musik
browseable = yes
read only = no
guest ok = no
admin users = Karsten
[Data]
root preexec = "/opt/rockstor/bin/mnt-share Data"
root preexec close = yes
comment = Data
path = /mnt2/Data
browseable = yes
read only = no
guest ok = no
admin users = Karsten
####END: Rockstor SAMBA CONFIG####

In the /var/log/ direcory there are two files log.nmdb and log.smdb, both are 0 bytes. in /var/log/old/ the same files are present.

log.nmdb:

[2017/04/19 19:16:16.907668, 0] …/lib/util/become_daemon.c:124(daemon_ready)
STATUS=daemon ‘nmbd’ finished starting up and ready to serve connections
[2017/04/19 19:16:39.688080, 0] …/lib/util/become_daemon.c:124(daemon_ready)
STATUS=daemon ‘nmbd’ finished starting up and ready to serve connections
[2017/04/19 19:16:56.656707, 0] …/lib/util/become_daemon.c:124(daemon_ready)
STATUS=daemon ‘nmbd’ finished starting up and ready to serve connections
[2017/04/19 19:17:10.659745, 0] …/lib/util/become_daemon.c:124(daemon_ready)
STATUS=daemon ‘nmbd’ finished starting up and ready to serve connections
[2017/04/19 19:17:33.539434, 0] …/source3/nmbd/nmbd_become_lmb.c:397(become_local_master_stage2)