samba - Jul 2002 - Winbind: SID-gid mappings lost after server crash

Hello again,

my server crashed today. It crashed because it ran out of file handles,
which is not Samba's fault but mine. The server runs Suse 7.2 and Samba
2.5.5 with WInbind installed. The sever crash didn't effect any file
systems, because I managed to properly shut the server down.

The problem is that after I rebooted, some or all of the SID - uid/gid
mappings got mixed up; e.g. gid 10000 used to be domain-users but became
domain-admins. As a result, users couldn't access files on the samba share.
How can this happen? I mean, the SID mapping database is a very precious
file, just like /etc/passwd. Can I trust Winbind or do I have to deploy a
periodic backup, via cron?

Any ideas?

Thanks.


-- Hannes

Hannes Schmidt wrote:
> 
> Hello again,
> 
> my server crashed today. It crashed because it ran out of file handles,
> which is not Samba's fault but mine. The server runs Suse 7.2 and Samba
> 2.5.5 with WInbind installed. The sever crash didn't effect any file
> systems, because I managed to properly shut the server down.
> 
> The problem is that after I rebooted, some or all of the SID - uid/gid
> mappings got mixed up; e.g. gid 10000 used to be domain-users but became
> domain-admins. As a result, users couldn't access files on the samba
share.
> How can this happen? I mean, the SID mapping database is a very precious
> file, just like /etc/passwd. Can I trust Winbind or do I have to deploy a
> periodic backup, via cron?
A tool has been added to recent versions of Samba (I think 2.2.5 should
have it) called 'tdbbackup' which can be used to back up tdbs with
cron.  It is written so as not to conflict with the normal reads/writes
on the database, and should extract a valid duplicate.

Andrew Bartlett

-- 
Andrew Bartlett                                 abartlet@pcug.org.au
Manager, Authentication Subsystems, Samba Team  abartlet@samba.org
Student Network Administrator, Hawker College   abartlet@hawkerc.net
http://samba.org     http://build.samba.org     http://hawkerc.net