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Distributed Filesystems for Linux?
Zoneball looked at 3 distributed filesystems, here are his thoughts:
" Open AFS was the solution I chose because I have the experience with it from college. For performance, AFS was built with an intelligent client-side cache, but did not support network disconnects nicely. But there are other alternatives out there.
Coda appears to be a research fork from an earlier version of AFS. Coda supports disconnected operations. But, the consensus on the Usenet (when I looked into filesystems a while ago) was that Coda was still too 'experimental.'
Intermezzo looks like it was started with the lessons learned from Coda, but (again from Usenet) people have said that it is still too unstable and it crashes their servers. The last 'news' on their site is dated almost a year ago, so I don't even know if it's being developed or not"
So if you were to recommend a distributed filesystem for Linux machines, would you choose one of the three filesystems listed here, or something else entirely?
It seems like a distributed filesystem might be overkill for your needs. If what you really want is the appearance of a single common machine, why not just pick one as a server, and set up your other boxes as X clients. You can even pull out most of their memory and storage, and stick it in the server, thus turning them all into pretty powerful machines.
Money I owe, money-iy-ay
I usually use rsync for one way backups, and unison where I need 2 way synchronization.
Rsync is nice because you can update lots of files very quickly, as it only moves binary diff's between files. Also, if it is a costly network link, you have the option to specify max transfer rates, so you don't kill your pipe when it runs from your cron job.
Unison is nice because it is pretty smart about determining which files should be moved, and can correctly handle new and deleted files on either end of the link. Plus it supports doing all of it's comm via ssh, so it's secure.
rsync
unison
The downside to both of these being that neither of them are instantaneous. However, I've had much success running both of these as often as every 5 minutes. Just make sure that you launch them from a script that is smart enough to check for already running instances before it starts trying to move data.
Nope, NFS is -not- a distributed file system. NFS is a point to point file system. And, unless you are using kerberized NFS, it is not secure.
The only file system that is truely distributed, has a global namespace, replication, and fault tolerance is AFS.
NFS is pretty much the same as CIFS for Windows. And, version 4 still doesn't have global namespace and volume location.
So, NFS can't be a common answer because it isn't even allowed to be in the game.
+4 cents.
That's like saying "jumping off a cliff is not the most intelligent thing to do." NFS is easily the LEAST secure option of ANY filesharing system.
NFS is only appropriate on a 100% secured(physical and network-level) network. If anyone/someone can plug in, forget it. If anyone has root on ANY system or there are ANY non-unix systems, forget it. If ANY system is physically accessible and can be booted off, say, a CDROM, forget it. The only major security tool at your disposal is access by IP, which is pathetic. Oh, and you can block root access.
Even though you can block root access for some/all clients, it's still massively insecure, and this remains NFS's greatest problem. You have zero way of authenticating a system. NFS is like a store where you could walk in, pick up any item you wanted, and say "I'm Joe Shmoe, bill me for this!" and they'd say "Right-o!" without even looking at you. All systems with the right IPs are explicitly trusted, and their user/permissions setups are also explicitly trusted.
NFS is a pretty good performer, especially when tuned right and on a non-broken client(which linux is VERY far from.) However, its entire security model is in dire need of a complete overhaul. There needs to be a way to authenticate hosts, for one, more similar to WinNT's domain setup, which is actually incredibly intelligent(aside from the weak LANMAN encryption.) The administrative functionality in NFS can't compare to the features that have been available to MacOS and Windows administrators for over a decade, and it's purely embarassing.
Either that, or AFS/Coda need to get a lot more documentation and (for Coda)implementation fixes. The unix world desperately needs a good filesharing system...
Please help metamoderate.
Other options like LDAPS and Kerberos offer at least some form of security.
ypcat, then brute force attack on the resulting passwd file is as old as dirt, and sadly still works. I was a bit dissappointed when I saw NIS as a required service on the Redhat cert syllabus.
This may sound harsh, but I don't think there is much excuse for run NIS in this day and age. Anyone who does this in an environment where security is a concerns deserves what they get.
Based on upvotes, Ageism is the only "-ism" Slashdotters care about and think isn't SJW
It's been featured on slashdot before.
Non-Linux Penguins ?
In the medium term, however, I think WebDAV will become a better option, because it can be served and accessed with standard web servers and clients, in addition to being mappable onto the file system.
The Linux kernel already has WebDAV support (CODA hooks plus some user-mode process), although I'm not sure how well it works.
I'm from the same lab from which SFS comes, so I'm a bit biased, but I've been using it in a production setting for the last two years. My major use is to work from home and access my MIT filesystem remotely. I also maintain a network of ~40 machines distributed around the world, and I use SFS to provide access to centralized home directories on them. Very, very convenient. The software is stable, and the support is good. It works on *BSD and Linux. It also works on some versions of MacOS X, but may require an upgraded gcc on the latest (see the fs.net mail archives).
Highly recommend cheking it out. Mega convenient.