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# The Answer Gang

By Jim Dennis, Jason Creighton, Chris G, Karl-Heinz, and... (meet the Gang) ... the Editors of Linux Gazette... and You!

### Network File Systems.

From mso@oz.net

Answered By: Rick Moen, Lew Pitcher, Jimmy O'Regan, Bruce Ferrell, Neil Youngman

What other choice is there besides Samba? Am I wrong for dismissing Samba due to its Microsoft taint?

(I do have to use Samba at work. So far it's been fine except I had to use the "cifs" filesystem instead of "smbfs". Apparently our server pretends to speak the older smbfs but actually doesn't.)

> [Rick] Well, if you need help disposing of those troublesome spare CPU cycles, there's always SFS (http://www.fs.net).

> Personally, my preferred solution is called SMTP, aka "Please drop the mail off right here where I am, thanks" -- for values of "where I am" equating to "the machine I ssh to, where mutt is left running permanently under GNU screen ".

> Tridge's reported solution is to use rsync (what else?) to mirror his mbox between his SMTP host and whatever machine he's sitting at.

OK. I meant for the general problem of mounting remote filesystems, not the specific problem of remote mailboxes.

> [Rick] I have nothing against you changing the focus of the discussion in that fashion; I just note that you've done so. Enjoy.

For that there's only NFS and Samba? (rsync, scp, and ftp don't count

It looks like SFS on Linux is built on top of NFS, so I'm not sure it counts as a "third" one. http://www.fs.net/sfswww/linux

The reason for my question is, there doesn't seem to be a "good" solution for sharing filesystems on Linux. For years I keep hearing:

> NFS: Unreliable! Doesn't play well with file locking!
> Samba: Evil! Microsoft! Proprietary protocol! Embrace and extend!

So what's the organization that wants a central fileserver to do?

> [Rick] Take your pick:

> 1. AFS, or
> 2. It depends.

Did Microsoft in fact create something better than NFS (better = more reliable and better designed), or is it just different?

> [Rick] They're different. It would take a long time to go through the differences, and I'll leave that to some other poster.

> [Lew] I won't comment on "better than NFS or just different", but I will take exception to the implication that Microsoft created the protocol.

> [Rick] I also recommend hearing hearing Jeremy Alison give his standard lecture, if people want to hear the full details of just how bad CIFS/SMB really is.

> [Lew] I will give Microsoft credit for extending an already existing protocol, but the basics come from IBM's NETBIOS.

> [Jimmy] Well, there are actually three different fileserving systems in the heap that is MS fileserving: NetBIOS, CIFS, and DCE DFS. CIFS may or may not depend on one or both of the others.

> MS's file serving is much, much better for file locking (but you only get the benefits of that from software that uses MS's locking API). It's also better to use Samba in an environment where there are several Unix variants, and you care about ACLs -- the Samba team 'embraced and extended'[1] CIFS to add marshalling for the various ACL types, which NFS doesn't do. (Well, NFS4 might do, I don't know).

> [1] They just like saying that, as far as I can make out. AFAICT, they just added an extension that plays well with others, and looks like any other unknown DCOM interface to clients that don't look for it -- it doesn't get drunk at the party and throw up on the other guests.

> [Bruce] Umm Jimmy, aren't NetBIOS/NetBEUI simply transport protocols? I think it might be more appropriate to say SMB and DCE DFS. And DCE DFS is actually built on top of SMB, but I could be wrong there. I just set these things up. I'm too busy to look at the messages anymore. And I think you neglected NCPFS... Not that anyone does much with Novell protocols anymore.

> [Jimmy] ...cue brain dump.

> This may not be entirely accurate, because: it's 6am, and though I was working nights last night, I didn't sleep much during the day in the hopes of readjusting to normal hours, and this is stuff I mostly learned back in the days of NT4, when I was in college, and went a bit further than strictly necessary in my studies for the MCSE exams I was never able to afford to take, though fortified with some investigations last year when Mike was asking about smbfs vs cifs. The article I wrote about outliners came the month after that, and AFAIR I included an example outliner file that contained some specifics, such as RFC numbers etc.

> - NetBIOS is an API (originally, IIRC, a set of DOS interrupts)
> - SMB is the part most people think of when they think of NetBIOS, but it actually uses a transport protocol such as NBT (NetBIOS over TCP/IP), NetBEUI, or NetBIOS over SPX.
> - SMB, NetBIOS, and possibly NBT were created by IBM
> - Microsoft extended these, originally while working with IBM on OS/2 for LanManager (y'know, the easily crackable password hashes that made NT's network authentication so horribly insecure)
> - CIFS is a version of SMB that doesn't require NBT -- that's why smbfs and cifs are separate kernel modules -- that also includes extensions for NTFS's features such as multiple file streams[1]

> - DCE DFS is something like NFS, over DCE RPC instead of Sun RPC
> - Microsoft uses an extended version of DCE RPC, Object RPC, as the basis for DCOM. COM interfaces are implemented locally using C++ vtables, which are marshalled over ORPC, which in turn is passed over NT's (network) Named Pipes: (extended) DCE RPC over SMB/CIFS.

> I didn't mention ncpfs because I was answering the second question (NFS vs. Samba), not the first (any network file system).

> [1] This is one of the places where NT shows its VMS heritage, as all file streams are preceded by ::$, such as ::$DATA, where the data is contained. (If that seems familiar, it may be because of the IIS flaw where it would send you the unprocessed source of ASP files if you appended ::$DATA to the file name).

And now IBM has dumped OS/2 and encouraged users to migrate to Linux. http://www-306.ibm.com/software/os/warp/migration.html http://slashdot.org/article.pl?sid=05/07/15/0245221&tid=136&tid=190

(Scratches head.) There are still OS/2 users out there? And they are more technical than Windows or Mac users who are scared of Linux?

> [Neil] Heck, there are still VMS users out there, there are probably still RSX users out there. Generally these are people who have specific requirements, e.g. real time, stability, security, that have had the sense not to jump on the Windows bandwagon, because it doesn't meet their requirements.

> So yes, I reckon OS/2 users are generally more technical than "Mac and Windows users who are scared of linux". They may migrate to Linux, but they will do it when they are convinced it meets their requirements better than the alternatives and when it suits them, not a minute before.

> [Lew] You bet. OS/2 is/was heavily used in the banking industry as 'Teller' terminal systems and as operator control systems/interface systems to IBM mainframes.

> My employer (a Canadian bank) has a multi-year project currently running to migrate our approx 15,000 OS/2 branch workstations and branch servers to another OS. Linux was considered, but in the end, my employer went with WinXP.

> Our OS/2 users are no more technical than the cashier in your local grocery store. Our OS/2 applications are quite sophisticated.

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Published in issue 117 of Linux Gazette August 2005

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