[Samba] Samba suddenly acting strangely

[Rowland Penny]

On Thu, 23 May 2024 19:20:04 +0200
Andrea Venturoli via samba <samba at lists.samba.org> wrote:

> Hello.
> 
> I know my description of the problem will be vague... I'm not asking
> for specific help, rather for some directions on where to look in
> order to understand it.
> 
> I've got several setups which are all alike:
> _ FreeBSD (currently 13.2, 13.3 or, rarely, 14.0);
> _ ZFS;
> _ two jails: one for an AD DC and one for a member fileserver;
> _ Samba <4.17 (in the past), 4.17 (still installed in some places) or 
> 4.19 (upgrading all instances is underway);
> _ no use of ACLs.
> 
> This setup usually works fine.
> 
> However, from time to time, the fileserver starts acting stangely;
> most of the times this happened after either the DC or the FS was
> upgraded (e.g. from 4.17 to 4.19), but I also saw this all of a
> sudden without any apparent external reason.
> 
> 
> 
> Symptoms include one or more of the following:
> 
> _ intermittent "file not found" problem, when the file is there (e.g. 
> run a program from a network share and it will complain some DLLs are 
> missing; run it again and it might work);
> _ directory listings missing some subdirectories or files, but moving
> to another directory and coming back might show everything;
> 
> _ inability to open any document (e.g. Word), but ability to copy the 
> file to a local folder (and then use it properly);
> _ Adobe Acrobat Reader hanging when opening a PDF file from a share;
> 
> _ ability to enter any root folder of a share, but no second level
> folders;
> 
> _ inability to list shares, i.e opening "\\fileserver", running "NET 
> VIEW \\fileserver" or "smbclient -L //fileserver" hanging
> 
> 
> 
> I was always able to solve (although not necessarily at first try) by 
> doing one or both of:
> _ removing DOSATTRIB extended attribute from all files/directories;
> _ wiping Samba's databases, starting from scratch and rejoining the
> domain.
> 
> 
> 
> Unfortunately I wasn't able to save some useful logs yet, but I think
> I saw two strange things:
> _ when a client tried accessing some file and failed, the logs were 
> populated with entries about other files (possibly in other shares) 
> which no one was attempting to access at that time;
> _ I'm not sure about this, but I think sometimes Samba mistook files
> for folders or vice-versa.
> 
> 
> 
> I'm very ignorant about Samba's internals, but one possible
> explanation I came up with is that Samba has some sort of database
> about files/folders and for some reason it started misapplying it
> (i.e. apply the wrong record of the database to a file/folder).
> Does this make any sense? Does this sort of database/cache/whatever
> exist?
> 
> 
> 
> Altough everything is working now on all the systems I manage, it 
> already happened at least five times (on at least three different 
> networks), so I'd like to be ready in case it happens again.
> 
> Any hint appreciated.
> 
>   bye & Thanks
> 	av.
> 

I wonder if this (fixed) bug has anything to do with your Problem ?

https://bugzilla.samba.org/show_bug.cgi?id=15093

If it does, then upgrading to 4.19.x should fix it .

Rowland