[Samba] samba-tool domain backup offline stalls

[James B. Byrne]

On Thu, July 23, 2020 17:02, Andrew Bartlett wrote:
>
>>
>> root 36800  0.8  0.0  12556  2788  1  SJ   16:49   0:00.01
>> /usr/local/bin/tdbbackup -s .copy.tdb
>> /var/db/samba4/private/secrets.ldb
>
> And, using whatever FreeBSD replaces lslocks with, is blocking that?

I am not aware of what information lslocks provides.  However, the following
may be useful:

  File "/usr/local/lib/python3.7/site-packages/samba/netcmd/domain_backup.py",
line 924, in offline_tdb_copy
    tdb.open(path)
A transaction is still active in ldb context [0x800a9c6a0] on
/var/db/samba4/private/secrets.ldb


[root at smb4-2 ~ (master)]# lsof -p 57982
COMMAND     PID USER   FD   TYPE                DEVICE SIZE/OFF   NODE NAME
tdbbackup 57982 root  cwd   VDIR 1879478894,3590381084       63     14
/zroot/iocage/jails/smb4-2/root -- root
. . .
tdbbackup 57982 root    3u  VREG 1879478894,3590381084  1286144 256159
/zroot/iocage/jails/smb4-2/root -- var/db/samba4/private/secrets.ldb

tdbbackup 57982 root    4u  VREG 1879478894,3590381084    40172 200076
/zroot/iocage/jails/smb4-2/root (zroot/iocage/jails/smb4-2/root)

The u after the file number (3u) indicates that the file is locked for update.

fstat provides this
[root at smb4-2 ~ (master)]# fstat -p 57982
USER     CMD          PID   FD MOUNT      INUM MODE         SZ|DV R/W
root     tdbbackup  57982 text /        205969 -rwxr-xr-x   19472  r
root     tdbbackup  57982 ctty [restricted]    755 crw--w----   pts/5 rw
root     tdbbackup  57982   wd /            14 drwxr-xr-x      63  r
root     tdbbackup  57982 root /             4 drwxr-xr-x      22  r
root     tdbbackup  57982 jail /             4 drwxr-xr-x      22  r
root     tdbbackup  57982    0 [restricted]    755 crw--w----   pts/5 rw
root     tdbbackup  57982    1 [restricted]    755 crw--w----   pts/5 rw
root     tdbbackup  57982    2 [restricted]    755 crw--w----   pts/5 rw
root     tdbbackup  57982    3 /        256159 -rw-------  1286144 rw
root     tdbbackup  57982    4 /        200076 -rw-------   40172 rw


>
> Does this still fail with Samba stopped?
>

Yes.  Online and offline backups both fail.  Offline gives no indication of
what it is waiting on and neither does tdbbackup.  Online fails trying to
attach to nbt ports.

Under separate cover I have sent you the output from dtruss run with both the
locked and unlocked runs of tdbbackup.  The unlocked run completes.  The locked
run hangs.

-- 
***          e-Mail is NOT a SECURE channel          ***
        Do NOT transmit sensitive data via e-Mail
   Unencrypted messages have no legal claim to privacy
 Do NOT open attachments nor follow links sent by e-Mail

James B. Byrne                mailto:ByrneJB at Harte-Lyne.ca
Harte & Lyne Limited          http://www.harte-lyne.ca
9 Brockley Drive              vox: +1 905 561 1241
Hamilton, Ontario             fax: +1 905 561 0757
Canada  L8E 3C3