Distributed Filesystems for Linux?

zoneball asks: "What would you use for a distributed file system for Linux? I have several GNU/Linix machines running at home, and wanted to be able to see more or less the same file tree (especially all the ~user directories) regardless of which machine I'm connected to, and where the traversal into the distributed file system space is largely transparent for the end-user. Are there any URLs or documents that compare the features, bugs, road map, stability of these and other distributed filesystems? Which offers the best stability and protection from future obsolescence?"

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?

Comments

Future obsolescence ?

[Rosco P. Coltrane]

Which offers the best stability and protection from future obsolescence?

This guy must have installed too many versions of the same Microsoft products.
In the GNU/Linux world, BSD world, and to some extend in the entire Unix world, good designs do not become obsolete. Even not-so-good designs often stick around, for the sake of backward compatibility. In the newest greatest Linux kernel, you can still have a.out support, NFS, Minix, FAT16 filesystem support ... You can still configure you networking using scripts for 2.0- or 2.2-based distros. You can often use 20 year old programs under Unix, albeit sometimes with some effort.

Only in the M$ world is obsolescence such a big issue, because that obsolescence is planned. In short, don't worry that much about obsolescence : if Coda is as good as it looks, it'll be there for a long time. If SomeCrappyDistributedFS FileSystem is used by enough users, it'll stay around for compatibility's sake anyway, even if it sucks.

Re:NFS

[gallir]

Naaaaaaaaaa.....

NFS is not distributed, it's only "networked" or "remote". I t doesn't support any: replication, disconnection, sharing, distribution. It is centralised, requires the same user names|numberpace and security.

In one word, it's far away of the requirements, at least if you compare them with the listed FS in the question.

AFS vs NFS

[runderwo]

It takes more time to set up an AFS cell than a NFS server, but the rewards are pretty tremendous IMO.

It's become such a part of my day to day life that I can't really describe the things I was missing before. The best things about it are probably the strong, flexible security and ease of administration. It also gives you everything you need from a small shop all the way up to a globally available decentralized data store.

There seems to be a good comparison here. I would strongly recommend AFS for all of your distributed filesystem needs. (The OpenAFS developers are cool too!)

Re:NFS

[nosferatu-man]

"For every complex problem, there is an answer that is clear, simple, and wrong." -- HL Mencken

'jfb

Re:NFS

[tuxlove]

I know that this is going to be the most common answer, but just go with NFS.

This is what immediately came to mind for me too. Except for one thing. NFS is not a distributed filesystem. It's merely a network filesystem. The data itself actually resides only in one central place, and is not distributed in any way. Storage is not shared across machines, and therefore NFS is limited, in performance and redundancy, to the levels that single storage point represents. If it's an infinitely scalable, fault-tolerant machine, then the difference approaches academic. Otherwise, the fact that NFS is not really a distributed filesystem is an important distinction.

Symlinks are your friend!

[billstewart]

Yes, there are applications where you want a real, heavy-duty, full-scale Distributed File System. The last time I looked at AFS it had too much Transarc commerciality in the way of using it, but that was a Decade Ago. If the OpenAFS works, it's probably a great choice.

But for a lot of applications, you simply don't need that much, and you've got some way to contain the security risks, and NFS can be enough. It's easy enough to set up, and if all you're *really* trying to do is make sure that everybody sees their home directory as /home/~user, and sees the operating system in the usual places and the couple of important project directories as /projecta and /projectb, NFS with an automounter and a bunch of symlinks for your home directories is really just fine. They hide the fact that users ~aaron through ~azimuth are on boxa and ~beowulf through ~czucky are on boxbc etc. And yes, there are times you really want more than that, and letting your users go log onto the boxes where their disk drives really are to run their big Makes can be critical help. But for a lot of day-to-day applications, it really doesn't matter so much.