[Samba] samba 4.8.0 Time Machine crashes on Mac

[andrit at ukr.net]

Hello Adam,

have you tried to increase /run/lock tmpfs mount size on your server yet? On Debian it is 5MB by default that may be not enough for Samba. You can do it by adding the following line into /etc/fstab:

none  /run/lock  tmpfs  nodev,noexec,nosuid,size=10485760  0 0

and `sudo mount -o remount /run/lock' command (or just simply reboot).

Hope it helps.

Regards,

  Andriy

On Mar 21 13:34:21 UTC 2018 Adam Błaszczykowski wrote:
> Hello,
> 
> I've encountered recurring issue with samba crashes when creating initial
> Time Machine backup on samba share from Mac. Whole scenario, details about
> software and logs are below.
> 
> On Mac client: connected to smb share with "valid user" account; added smb
> share as Time Machine disk.
> Time machine has been set for automatic backup, I've selected Back Up Now.
> Connection dies around 20%-30% of initial backup creation, samba share is
> still on Finder list and can't be unmounted with an icon from gui. There
> are no other Time Machine disks in use.
> 
> 
> Server:
> Linux debian 4.9.0-6-amd64 #1 SMP Debian 4.9.82-1+deb9u3 (2018-03-02)
> x86_64 GNU/Linux
> smbd/nmbd Version 4.8.0
> Client:
> macOS High Sierra
> Version 10.13.3 (17D47)
> 
> Server:
> smb.conf:
> [global]
>     workgroup = SAMBA
>     security = user
>     passdb backend = tdbsam
>     durable handles = yes
>     kernel oplocks = no
>     kernel share modes = no
>     posix locking = no
>     fruit:time machine = yes
>     invalid users = root
>     encrypt passwords = yes
> 
> [TimeMachineD]
>     path = /data
>     browseable = yes
>     fruit:time machine = yes
>     vfs objects = catia fruit streams_xattr
>     fruit:aapl = yes
>     valid users = tmachine
>     read only = No
>     inherit acls = yes
> 
> 
> Expected TimeMachine snapshot: 130GB
> Samba share size: 950GB
> 
> smbd.log:
> [2018/03/21 11:15:13.589109,  0]
> ../source3/locking/share_mode_lock.c:439(share_mode_data_destructor)
>   store returned NT_STATUS_UNSUCCESSFUL
> [2018/03/21 11:15:13.589216,  0] ../source3/lib/util.c:815(smb_panic_s3)
>   PANIC (pid 933): could not store share mode entry: NT_STATUS_UNSUCCESSFUL
> [2018/03/21 11:15:13.590549,  0] ../source3/lib/util.c:926(log_stack_trace)