the ever present "Failed to retrieve share list from server"

[CliveMcCarthy]

There are many many posts on this issue on this forum and others and I haven't found anything definitive. I experience the "Failed to retrieve share list from server" from time to time. It isn't consistent at all. Sometime things work just fine for days & days... then nothing. I reboot my router, access points and my clients then wait forever, and sometimes things get back to normal. Sometimes not.

I have a network with many Linux machines, a few Win XP machines and a Mac. When things are bad it is impossible to find shared folders EVEN ON OTHER LINUX MACHINES -- the machines just don't show up at all. If I try the "Window's Network" I can sometimes find a WORKGROUP names but they just lead to the "Failed to retrieve share list from server" message. I use a very convenient utility called which can be found at: http://www.overlooksoft.com/download -- I have it on my phone as well as various laptop/desktop machines and it clearly identifies what machines are on my network, what their names are and their ip addresses. The utility nbtscan also finds all the machines on the network. It works all the time so why can't Nautilus?

The curious thing is that the Mac on the network is visible! I suspect that it isn't a Windows/Samba thing but perhaps some kind of interaction between Nautilus, Samba and how DHCP servers commonly function. I just can't get a reliable Linux-to-Linux shared network functioning...

I experience this with Ubuntu 10.10 and now with Mint 15 (Ubuntu 13.04)

[dmizer]

Have you taken a look here? http://ubuntuforums.org/showthread.php?t=1169149

There is a specific fix related to this error listed under "Problem 5".

[CliveMcCarthy]

Thanks for replying, but I don't have a "Windows" browsing problem. I have a Linux-to-Linux browsing problem. Or, perhaps to put it another way, I have a Samba browsing problem?

Currently I'm sitting at a desk with three Linux machines all wired into a router. When I use the Nautilus view of the network all I see is my wife's Mac and the "Windows Network" -- nothing else. Normally I would see the three Linux machines as well and be able to navigate to their shared directories.

If I run nbtscan I can see everything that is active on the network. If I run smbtree I can see everything too. Here's the output from smbtree​.

KIBBUTZCLIVEWORKGROUP
    \\VOSTROV13              VostroV13 server (Samba, LinuxMint)
        \\VOSTROV13\HP-LaserJet-1200    HP LaserJet 1200
        \\VOSTROV13\HL2270DW           HL2270DW
        \\VOSTROV13\print$             Printer Drivers
        \\VOSTROV13\shareddocs         
        \\VOSTROV13\music              
        \\VOSTROV13\IPC$               IPC Service (VostroV13 server (Samba, LinuxMint))
    \\Q9550                  Q9550 server (Samba, Ubuntu)
        \\Q9550\q9550shareddocs    
        \\Q9550\HL2270DW           HL2270DW
        \\Q9550\HP-LaserJet-4L     HP LaserJet 4L
        \\Q9550\Tricias-HP-LaserJet-1200    Hewlett-Packard HP LaserJet 1200
        \\Q9550\print$             Printer Drivers
        \\Q9550\IPC$               IPC Service (Q9550 server (Samba, Ubuntu))
    \\NETFLIX_HD             Zotac Ion
        \\NETFLIX_HD\SharedDocs         
        \\NETFLIX_HD\IPC$               Remote IPC
    \\MACBOOKPRO-AB2A        Tricia Bell's MacBook Pro
    \\G750                   G750 server (Samba, LinuxMint)
        \\G750\HP_LaserJet_Professional_P1102w    HP LaserJet Professional P1102w @ Tricia Bell’s MacBook Pro
        \\G750\HP_LaserJet_1200    HP LaserJet 1200 @ Tricia Bell’s MacBook Pro
        \\G750\print$             Printer Drivers
        \\G750\shareddocs         G750
        \\G750\IPC$               IPC Service (G750 server (Samba, LinuxMint))
    \\ARTSHOW24              artshow24 server (Samba, Ubuntu)
        \\ARTSHOW24\shareddocs         artshow15 shared
        \\ARTSHOW24\print$             Printer Drivers
        \\ARTSHOW24\IPC$               IPC Service (artshow24 server (Samba, Ubuntu))
    \\ARTSHOW21              artshow21 server (Samba, Ubuntu)
        \\ARTSHOW21\shareddocs         artshow15 shared
        \\ARTSHOW21\print$             Printer Drivers
        \\ARTSHOW21\IPC$               IPC Service (artshow21 server (Samba, Ubuntu))
    \\ARTDEMO                artdemo server (Samba, Ubuntu)
        \\ARTDEMO\shareddocs         
        \\ARTDEMO\C                  development on artdemo
        \\ARTDEMO\music              
        \\ARTDEMO\print$             Printer Drivers
        \\ARTDEMO\IPC$               IPC Service (artdemo server (Samba, Ubuntu))

[CliveMcCarthy]

And so, 24 hours later, this Ubuntu machine still is unable to see other shares on other Linux machines. I did reboot the two other Linux machines on my desk and they now can see one another's shares. This machine remains blind. There is something fundamentally wrong with the Nautilus-Samba interface. It somehow caches a view of the network that it NEVER refreshes. Smbtree and Nbtscan can see the entire network on this machine but Nautilus remains ignorant?

However, somehow the lone Mac on the network shows up! Windows machines -- no, Linux machines -- no. What weird thing is Apple (Darwin) doing that it is more compatible with Ubuntu than Ubuntu is with itself?

[Morbius1]

I can reproduce some of your symptoms quite easily.

[1] Apple uses 2 mechanisms to announce the availability of a samba share and one of them is zeroconf. Linux also speaks zeroconf and since this is outside the normal samba nmbd process it will display the zerconf enabled service outside of the "Windows Network" folder.

[2] The reason "Windows Network" is empty is because of this:

KIBBUTZCLIVEWORKGROUP

Has to be 15 characters or less in length and yours is 21. I replaced my workgroup name with yours and can reproduce your error. If I change it to something like this everything returns to normal:

KIBBUTZCLIVEWRK

So edit /etc/samba/smb.conf and change your workgroup name to something 15 characters or less in length. While you're in there add another line right under the workgroup line:

name resolve order = bcast host lmhosts wins

Then restart the samba services:

sudo service smbd restart
sudo service nmbd restart

Do that to all your Linux machines and then go make yourself a nice pot of tea. When you restart nmbd the network has a hissy fit and you need to give it a few minutes to calm itself.

[CliveMcCarthy]

Morbius, thank you for your response. I shall follow your advice.

I have in the past attempted to modify the name resolve order but the network still seem to exhibit problems. Perhaps you can explain, or direct me to a source of information, about how names are resolved? In general, I think order dependent things are to be avoided -- with bcast, host, lmhosts and wins there are 24 ways of setting the configuration and maybe only one that is correct. Since smbtree and nbtscan can figure things out for themselves why can't Nautilus? Can't Nautilus try them all, as I presume nbtscan does? Clearly the Apple Bonjour/zeroconf, that you mentioned, is the most robust method since these shares always show up.

What is troubling is that the network seems to operate satisfactorily for weeks at a time (even with an apparently discrepant name resolution order) and then, spontaneously, each Linux machine then seems to become trapped unable to see anything on the network (except for the Apple Mac) even if rebooted.

My machines all seem to be back with the ability to see each other's shares. Perhaps I should do an experiment and try all 24 orderings of the name resolution list, but since I know the network can work satisfactorily for weeks with a 'wrong' order, I won't be able prove anything conclusively. I've had this problem for several years and I'd like to get it nailed.

What exactly is the mechanism? Does Nautilus/Samba broadcast to the network and make a 'who is out there?' kind of request and get back a list of names and ip addresses? Or does Nautilus/Samba simply communicate with the DHCP server and request the server's list of names and addresses?

I'm also perplexed that I have seen posts suggesting edits to ordering of things in /etc/nsswitch.conf as well as /etc/samba/smb.conf

Mine reads:

hosts:          files mdns4_minimal [NOTFOUND=return] dns wins mdns4

How do the settings in nsswitch.conf and smb.conf interact? Can things get screwy if these is some way conflict?

---

I took a fresh look at the workgroup name and it seems I posted the output of smbtree incorrectly. There are in fact two workgroups, but they have names shorter than 15 chars.

KIBBUTZ
CLIVEWORKGROUP
    \\VOSTROV13              VostroV13 server (Samba, LinuxMint)
        \\VOSTROV13\HP-LaserJet-1200    HP LaserJet 1200
        \\VOSTROV13\HL2270DW           HL2270DW
        \\VOSTROV13\print$             Printer Drivers
        \\VOSTROV13\shareddocs         
        \\VOSTROV13\music              
        \\VOSTROV13\IPC$               IPC Service (VostroV13 server (Samba, LinuxMint))
    \\Q9550                  Q9550 server (Samba, Ubuntu)
        \\Q9550\q9550shareddocs    
        \\Q9550\HL2270DW           HL2270DW
        \\Q9550\HP-LaserJet-4L     HP LaserJet 4L
        \\Q9550\Tricias-HP-LaserJet-1200    Hewlett-Packard HP LaserJet 1200
        \\Q9550\print$             Printer Drivers
        \\Q9550\IPC$               IPC Service (Q9550 server (Samba, Ubuntu))
    \\NETFLIX_HD             Zotac Ion
        \\NETFLIX_HD\SharedDocs         
        \\NETFLIX_HD\IPC$               Remote IPC
    \\MACBOOKPRO-AB2A        Tricia Bell's MacBook Pro
    \\G750                   G750 server (Samba, LinuxMint)
        \\G750\HP_LaserJet_Professional_P1102w    HP LaserJet Professional P1102w @ Tricia Bell’s MacBook Pro
        \\G750\HP_LaserJet_1200    HP LaserJet 1200 @ Tricia Bell’s MacBook Pro
        \\G750\print$             Printer Drivers
        \\G750\shareddocs         G750
        \\G750\IPC$               IPC Service (G750 server (Samba, LinuxMint))

...

It looks like a newline screw-up when I pasted the output.

[Morbius1]

** Don't obsess with all the available permutations of "name resolve order" since host, lmhosts, and wins are non functional by default leaving bcast or broadcast ( same as in Windows ) as the only one that works. And they way you described how bcast works is essentially correct.

** The Apple way is superior - at least for home networks - primarily because it doesn't depend on nmbd, workgroups, and netbios names to function. Since Linux can speak the language you can always do the poor man's apple. For example:

nautilus smb://VOSTROV13.local

Then bookmark it. Just remember that zerconf relies on the hostname not the netbios name. Samba forces the netbios to match the host but you may have overridden it smb.conf.

You can also create an avahi samba services file to mimic what OSX does.

*** And yes what you did to nsswitch is not they recommended way to do this sort of thing.

[CliveMcCarthy]

OK, I won't obsess about the ordering complexity, but if host, lmhosts, and wins are non-functional why shouldn't I just trash them and rely on bcast?

The Mac is clearly capable of getting on with things. The odd Windows XP machines might have difficulty perhaps?

There is something unstable in my network, at least as far as the Linux machines go, so purging redundant or non-functional name resolution schemes might help -- or at least narrow the diagnostic path. What you have explained is very helpful. I can presume that bcast is a zero-configuration protocol. I've been reading Wikipedia:

http://en.wikipedia.org/wiki/Zero_configuration_networking

so my DHCP server isn't likely at fault since it is hardly needed?

By default the name resolution order in smb.conf is commented out -- is this because bcast is the default? In which case there is something periodically going wrong with bcast because un-commenting the line was supposed to be a fix for the original problem.

My understanding now is that Nautilus retrieves data from Samba which in turn uses the bcast mechanism as a means of locating ip addresses for hostnames?

How should I set nsswitch if "hosts: files mdns4_minimal [NOTFOUND=return] dns wins mdns4" is incorrect?

Sorry if it seems I just won't let go of the issue, but this problem has dogged me for several years, and every time I work on it the problem 'goes away' only to resurface sometimes months later...

[Morbius1]

That's a lot of questions. Let's see how far I can get

OK, I won't obsess about the ordering complexity, but if host, lmhosts, and wins are non-functional why shouldn't I just trash them and rely on bcast?

Some people do just that. Member bab1 for example always recommends setting it to just bcast alone. I like to keep my options open so I keep them in. If everything was working perfectly it wouldn't matter what order they were in. Samba would go through each one in turn and find the one that works. Sometimes because of the choice of router or even the ISP they use things get gummed up.

The Mac is clearly capable of getting on with things. The odd Windows XP machines might have difficulty perhaps?

Windows can join the party with a partial implementation of bonjour - partial in the sense that they too can then connect to other machines with a \\hostname.local. But something has to be installed on Windows to make it work.

What you have explained is very helpful. I can presume that bcast is a zero-configuration protocol.

bcast is the linux implementation of a native Windows "node" mechanism called broadcast. Avahi is the zeroconf implementation and is contolled by the avahi-daemon service.

By default the name resolution order in smb.conf is commented out -- is this because bcast is the default?

You know, every single thing about Samba is unnecessarily complex and what you are referring to even messes up seasoned users of it. The ";" in front of the line is one recommendation and one used most often in a corporate setting. The default lists all four and has bcast last. In a corporate setting you want bcast last - you don't want 150 clients to broadcast their presence of the network.

The default nsswitch is this:

hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4

You will note that the mdns references relate to avahi/bonjour/zeroconf and is what makes *.local possible.

[CliveMcCarthy]

Excellent!

I'll put bcast first, restore nsswitch.conf to the default values on my main machines, and keep my fingers crossed. If things foul-up in the future I'll try restarting smbd & nmbd as my first line of attack.
Thank you for your patience and your understanding particularly:

"You know, every single thing about Samba is unnecessarily complex..."

I have to agree