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Tridgell Taking Samba Beyond POSIX
dW writes "The Australian hacker has been working on pushing Samba beyond the POSIX world and figuring out what work needs to be done to get Samba to support new filesystems such as XFS, ext3, and Storage Tank. The answer is nothing less than a complete rewrite of Samba's smbd code, which has become his latest pet project. Here's an interview with Andrew Tridgell on his latest Samba rewrite."
Out of the datacenter market!
You think that I'm crazy, you should see this guy!
They way I'm reading this support for things like XFS/ext3 etc is that samba will implment things such as native ACL's and such like. However I can help but wonder how these will be preserved if say the server is XFS and the Client FAT. The only think I can think of is some sort of file which stores it as Metadata. Of course if it was XFS -> ext3 then you might be able to convert to the native setup but it might be buggy and subject to the filesystem formats changing
Rus
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I think he means that instead of Samba presenting itself as a legacy CIFS file server it should serve files to a client expecting other file systems. So you could run Samba on AIX and tell your Linux box it's an ext3 connection.
Or maybe it's because the user level file systems on plan9 have made too much of a mark on me.
open, close, read, write & walk baby, s'all you need
There are places where the networks are not touching,and there are places where they are-Boeing's Lori Gunter
Yeah NFS is a better system. However in defense of MS they have document SMB (aka CIFS) so people can understand it. However virtually every other recent OS has support for NFS so it would be nice if MS included native support rather than just in their UNIX Tools which are cost extras
Rus
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Samba's existence is vastly important to the adoption by corporate management of perceived 'alternate' computing systems (i.e., Linux, Mac, sometimes Unix, as opposed to Windows) in the datacenter. The simple fact that there exists an easy-to-use, open source method of interconnecting disparate file systems, allowing multiple OS co-existance, is often the lynchpin in convincing managers to permit non-Windows systems to be deployed in a company. I have worked in several situations where employees have wanted to use Mac OSX desktops or Linux/Unix servers (etc.) in an all-Windows shop, and managers balked at the idea until they were convinced that data could still be exchanged, and that the 'alternative' OS'es could still 'talk' to the Windows machines.
With this established managerial behavior in mind, isn't it interesting that IBM would have hired Samba's creator outright, to work on a project which furthers Samba's ability to communicate with additional operating systems? Samba in many ways is a 'license to change' computers in a datacenter for IT staff. IBM has positioned itself to pump funding directly into the Samba project, as well as to have a say in which file systems it supports; this gives IBM the ability to write its own ticket in terms of promoting its disparate filesystem architectures' usage in the datacenter, alongside their Windows brethren.
Who's working on polishing up that ActiveDirectory and Kerberos stuff so I can continue to use my samba based PDC with WinXP.
It's neat that he's extending the SMB protocol to support some more of the native features of the underlying filesystems.
But I'd wager the lions share of it's user base want samba to replace/supplement Win2k Server, and soon Win2003.
This always happens in open source. Projects get pulled in a new direction before they're completed. Developers always want to work on neat stuff and get bogged down in the academics, and it doesnt produce a truly functional result.
There's nothing that can be done about it, it's his time, his decision. Still, it sure would be nice for samba to be a full member of a Windows 2000 domain.
I don't need no instructions to know how to rock!!!!
When I first read the headline, I thought that it said "Trogdor Taking Samba Beyond POSIX." I thought "Why would the burninator bother with this? Doesn't he have villages to burninate?" Yeah. I'll go ahead and read the article now...
The article was similar to Tridge's talk on the same subject at linux.conf.au in January - "towards full NTFS semantics in Samba."
The talk (in Ogg Speex audio format) and accompanying paper are on the linux.conf.au CD. There's a list of mirrors on their web site, both to mounted copies of the CD so you can download individual talks, and ISO images of the whole thing.
What he's talking about is taking advantage of "exotic" filesystems. Currently Samba just assumes it has a plain-old Posix filesystem like ext2 behind it, and does things less efficiently than might be possible
I'm not sure ext3 is a good example, but let's imagine it has a concept of transactions. Samba might be able to take advantage of that to provide a better implementation of CIFS, but to do that it has to know about ext3, more than that it's compatible with Posix.
Other examples: ACLs, case-sensitivity, multiple streams in files (like Macintosh resource forks), stuff like that.
I was on Monday and Tuesday on SambaXP where Tridge had talk about Samba 4. Also we discussed possibility of having completely Windows-compatible (and NFS v4) compatible ACLs on standard fs like XFS and ext3. Result was that Samba team needs a kernel interface for this so I'm going to hire some summer students for this and I expect some working code on autumn.
I don't know what they're talking about, but if you compile XFS in, all the acls libs, and then compile Samba, you get something that you couldn't tell from Windows. Apart from the uptime, the speed, the security....
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There can be only one perhaps?
You may think me a tired, old, cynic. I'd have to disagree about the tired bit.
Hmm, not so sure. All that portmap baggage is annoying. And there is no username level security.
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Cos AIX, Darwin, Linux, Digital Unix, HP-UX, Irix, MacOS X 10, Solaris, *BSD and Windows all have free client software...
So, by "majority of OSes"... Did you mean DOS?
Government of the people, by corporate executives, for corporate profits.
I don't think the Samba team is well. At least not in the head anyways.
These guys look at some of the uglyest packets in the world. And they keep doing it. And they keep coming back for more. Ever hear Tridge talk about whats going on inside the SMB packets? Hes not too hard on MS in the large public forums but see what happens when you hand him a VB or 5 before a talk... then he will give it to you without the sugar coating... Were talking odd sized data structures that may or may not be little endian. Most of the time the structures are hiding inside other structures and the inner and outer structures will have different bitness and different world alignments. Nest a few levels for even more pain. And then repeat. This is what these guys do for FUN! This is why I'm concerned about them.
Now they want to tackle other stuff as well? Maybe they could just throw in Novell's stuff for grins. Once they have done that, they will win the all time award for being the most saito masicistic coders ever. No one will ever be able to beat them. Ever. Its not even worth attempting to compete with them.
The parent poster writes:
else I'll be using NFS which is a much better protocol in every area.
Er, yes... like how NFS relies on the hostname for security, while SMB/CIFS relies on a password.
NFS is as (in)secure as the r* commands (rlogin, rcp, rsh). It relies on the client to authenticate the user, and the server only trusts certain clients (or anything pretending to be certain clients).
Now I'll admit, a good firewall should keep NFS safe. Under certain setups, even a good router should be enough. However, I prefer to think of a firewall as one layer of security - not my first, last, and only line of defense.
Although I'm not currently using it, AFS/Code seems to be a cross platform (win, mac, unix) secure replacement to NFS.
NFS might be a better protocol then SMB/CIFS in certain areas, but for security, SMB/CIFS wins (even the old versions of SMB that rely on plaintext passwords).
A complete rewrite? WTF? I thought smart developers learned a long time ago that rewrites are almost always a waste of time.
There are many issues to be overcome when doing a complete rewrite. As a developer, I understand the desire to rewrite something from scratch to make it feel better. You feel like you are doing something to improve the system. However, this hardly ever happens. Most developers face serious burn-out issues when they rewrite something. It's fun at first but as you realize the magnitude of what you're trying to do, you quickly start to burn out before you are even close to finishing.
The thing is, even if you do manage to rewrite everything, there will STILL be issues. Hacks, special conditions, etc. All the same types of issues that made you feel bad about the original version will be present in the new version. They may take a different form, but they will still be there.
Successful systems tend to just continue off the old code. Rewrite the problem areas, add things that are needed, etc. That's how you make forward progress. In the end, the only thing that matters is that it works. It doesn't matter how crappy you feel about the code, if it works then people can and will use it.
It's not an impossible task, I just think it's not the smartest thing to do.
The ratio of people to cake is too big
Actually, no- I'd rather have cross-platform file locking. Correct me if things have changed since 2000 when samba and netatalk developers were "thinking" about this problem, but...
It is a HUGE problem that netatalk, Samba, NFS, and the system itself don't share common file-locking, and some file-based applications like Visual Source Safe(still used by many shops) -require- file locks be across all the shares; if you don't have it, you run a serious chance of screwing things up.
WinNT/Win2k with Services for Macintosh is the only server I know of capable of cross-platform locking, and that is pathetic...
Please help metamoderate.
Instead of trying to simply take advantage of extended attributes of various filesystems, what about taking Samba the same route as NFS and implement some kernel-level support? Replace the existing kerne smb code with samba-based client/server bits, similar to NFS; a mix of knfsd and usreland bits like portmap. This could eliminate the many layers that could crop up simply by trying to make the daemon-only version use various filesystem bits.
Don't convert the ENTIRE samba to kernelspace; that would be pointless for samba on other platforms. But development of a 'kernel plugin' allowing Samba lower-level access to filesystem bits might be beneficial.
(yes, I'm ignoring the potential security foo at the moment and realize it's another portal of potential exploit.. but instead of adding more abstraction layers to the system it might be nice to simply access those wanted features directly).
'fester
Many opensource projects started out trying to emulate some other protocol, then overtook it and grabbed the lead.. then the proprietary protocol had to follow.
Samba is in a similar position. I think there are improvements to be made, efficiency, authentication, virutualhosts?(multiple domains/workgroups/subnets with the same daemon), better filesystem support, changes in the protocol making it faster, more efficient and unbreakable etc.
If Andrew can release improvements to samba for say win9x, 2000 and xp, replacing some networking DLLS,or just replacing microsoft network client, samba can be in a real leader position. MS SMB code is deinitely buggy or just inefficient, even on one subnet with 8 hosts. Improve that, release the improvement as GPL, and people will flock to it. Best form of marketing of Linux I can think of. OSSphobics will have no way out.
"Give orange me give eat orange me eat orange give me eat orange give me you." -Nim Chimpsky
Samba 2.2 has ACL support - for XFS, at least. I know because I use it now. It's not just a TNG feature.
..."Although I'm not currently using it, AFS/Code seems to be a cross platform (win, mac, unix) secure replacement to NFS."
AFS, or OpenAFS is not -only- a replacement for NFS it is way over NFS in terms of security and scalability. If you aren't using a global namespace filesystem, then you can't actually call yourself knowledgeable of system administration. The only replacement for AFS that is even close is Microsoft's "Win2k AD'd dfs", and even it is missing a large number of features that AFS has.
I'm rather shocked that people don't use global namespace network filesystems for data storage and application servers. The redundancy is excellent.
And, since AFS can be modularly seperated from the authentication system and client OS, it makes for an excellent tool for system upgrades.
Just my 2 cents.