Set up one computer as a server and rsync/ssh to it with either a cron job or at your whim.

I like Unison [upenn.edu] for this sort of thing.

www.dropbox.com

Dropbox is great. I use it between all my computers (PC and Linux) and I have absolutely 0 complaints with it!

of course you can. the ssh support was added on the top of rsync. It originally used the rsyncd daemon which I believe do not use encryption. (similar to rlogin for authentification)

Unison from UPenn http://www.cis.upenn.edu/~bcpierce/unison/ [upenn.edu]

Works on all the platforms you mentioned... It can synchronize 2 disparate directory trees (you made updates to files A, B, C on one system and D, E, F on another system and want to merge them) and when it can't figure out what to do it asks you.

Set up one computer as a master repository and do everything over SVN+SSH.

Its what I do for the complete working set I have, passing between 3+ systems, is everything is through subversion over SSH to a backed-up system.

Mercurial [selenic.com] for...

Windows [berkwood.com]

MacOS [berkwood.com]

For linux it should be in standard repos.

This way you can make changes on any of your systems and move them around as required, merging only when needed.

If you don't mind having to manually synchronize (and even this limitation can be worked around with a careful set up), I'll say Unison over SSH. It handles circular version conflict resolution quite well, it's not too difficult to setup if in the chain there's only a windows machine (so you don't need to setup a ssh server on the win box) and it's serving me very well. I don't know about OSX but I think it should work there good enough.
It has a nice GUI too to manually resolve nasty conflicts (e.g. you modified a document in on two different environments before the sync.)

I second the suggestion. It's basically like rsync except it's more like real synchronization. What I mean is, AFAIK with rsync you basically have to say, "Sync folder A and folder B by assuming that folder A is the copy I want to keep, and changing only folder B." With Unison, on the other hand, you can say, "Sync folders A and B by keeping track of when files get modified, and keeping the most recent version of each file. If a file has been modified in both folders since my last sync, let me know and ask me what to do."

One minor annoyance is the project page links to an OSX version that includes a Cocoa interface, and that's kind of a pain if you want to script it to run in the background. Even if you call it from the command line, the GUI will still open up. Also, if you install it from MacPorts, it doesn't do a good job of maintaining resource forks. Of course, if you're syncing to Linux or Windows, you might not care about resource forks.

I think the best place to get the OSX version is here: link [haifa.ac.il]

It's been a while since I've downloaded it, though.

I cannot say whether unison is the best solution, but it is one that I have been using for 7 years or more, between two desktops (home and work), a laptop an external hard drive and another offsite backup. These were on a variety of filesystems between Linux and Windows flavours. MacOS X should be no different.

While I have seen graphical interfaces to unison, the command line interface is so much easier to use.

I would definitely recommend unison... while it is not a revision control system it is an effective solution at working on the same set of files wherever you are provided you synchronise twice a day.

I;m a little confused if you are syncronizing, mirroring or backing up data. the title says synch, but time machine and jungle disk are more for backup, and at most can be used for mirroring a master rather than synching.

If you want to backup, take a look at Crashplan. It's got two unique features the other plans lack. 1) you can backup to your own physical media, not theirs. This solves the problem of how do you backup and restore say 200GB of data in less than a month to a remote service. if the disk is yours you do the initial backup locally, them move the disk to the remote location for incremental backups. And then you do the reverse when you need to do more than in incremental restore. 2) they will sell you just the software-- a one time cost-- and you don't have to pay for a monthly remote service cost unless you want to. in which case you just backup to a freinds computer that is hosting your disk. Your data is both safe and remote (and encypted) but you can also go get the drive is if you need it using your toyota rather than the internet.

On the other hand if you want syncronization then look into Unison. It appears the source forge project is not highly maintained but also mature enough to work well. it is cross platform and scriptable.

https://www.dropbox.com/ [dropbox.com]

"Free for Windows, Mac, and Linux"

Creates a folder that is kept in sync between different computers. You can share files with other dropbox users too via shared folders. 2GB or so of space is free. It also keeps multiple versions of files so you can go back to a previous version of a file if you need to.

I don't have any affiliation with the company, other than being a satisfied user.

Am I missing something here? What doesn't SVN do that you need? Clients exist for all named platforms and it handles OO, Latex, and source code files very well.

I sync between 3 computers using a hub-and-spoke system. My file server is the hub; my desktop and laptop both sync only with the file server.

Seconded. I use Unison between Linux and OSX with no trouble, and used Win32 in the past as well. It isn't perfect, but it's closest by a wide margin.

You don't even need to set up one as "the server". With the right options, mutual rsyncs between them will be fine.

• data integrity - check
• remote access - check
• automated incremental backups - check
• No limitations of software raid neither the need for expensive hardware raid - check
• Dead Simple to Use - check

Seriously what more do you want from a storage/backup solution ?

luckybackup is a gui for rsync and allows you to sync folders.

I use it to quickly backup everything. It doesn't allow versioning, but I use squashfs-tools to remove all redundant files and compress them with lzma. So I have a folder system of dates for versioning in a highly compressed squashfs file system container, that's mountable.

sudo apt-get install luckybackup squashfs-tools

I agree, unison is great. I used unison for several years to sync machines. It worked great for linux-linux, and seemed to mostly work for linux-mac/mac-linux syncs as well. The main problem was with resource forks causing a bunch of ._foo files, but there's not too much you can do about that if you're copying data from HFS+ to something else. It's been a while since I used unison (I gave up my desktop, and now only use a laptop.), but seems like unison has the ability to actually merge files by fire off something like meld [sourceforge.net] to resolve conflicts. That's a big win.

That problem is mentioned all over the net, what's not mentioned is that the problem stems from transfers across different OSs.

A suggestion that might be a work-around : Sync Windows to a smb share, and use unison locally on that directory.

I am not using windows, so I'm fine. But, I also can't guarantee that my suggestion works.

Note that newer releases of OpenSolaris have built-in kernel support for CIFS with ZFS.

  # zfs set sharesmb=on mypool/mydata
  # zfs set sharenfs=on mypool/mydata

Mapping between Unix UIDs and Windows SIDs is done transparently, and you can change things from the Windows GUI if desired and the ACLs will go live on the Unix side as well: SIDs are first class security objects. None of the usual Samba UID/SID kludginess (though (Open)Solaris comes with a Samba package if you want to go that route.)

Case-(in)sensitivity is also a user toggle away if so desired.

De-dupe was also recently committed to the code base. Crypto is being worked on and I think patches are available.

Do not forget about data de-dupe as well.. now you can have multiple copies of the data from point in time saves and it occupies less space.

Rsync has many options, which you can apply to amazing ends if you become an rsync wizard. Before I explain some of them, consider that setting up a CVS or SVN repo behind SSH might be the easiest thing to manage "some openoffice files, latex, and sourcecode". I even use CVS to manage my own calendar files.

With rsync you can use timestamps and -u (update) mode to only transfer from A to B if A is newer. You can run once in each direction to transfer a sparse mixture of files you have modified at either site. You lose if both sites are "newer" than the last sync time, as you will not detect a conflict.

With rsync -n (no modification) you can simulate a transfer, review the affected file list, and intervene with special cases before you let it destroy data. With --exclude and --include patterns, you can selectively copy only certain files you wanted from a complex tree.

You are playing with fire if you do any of this without a backup system which can allow you to recover from an rsync mistake.

Time capsules appear to have a MTBF of ~18 mos; the power supply dies. Apple will replace it via an APP-covered computer that uses it, but not if you crack the case to get the hard drive out.

So, either eat the $$ after 18 mos to save your 18 mos of backups, or give Apple your data for a refurbed unit, or find a backup solution for your backup solution.

I'm not buyin' another one.

You're going to have some file semantics issues in any case. Those introduced by CIFS (don't see how ZFS is a factor) are pretty easy to deal with.

Better yet, use Mercurial (or any other distributed version control system). It is designed for this kind of use!

I have three clones (of a project), one in desktop, one in laptop and one in an USB stick. Just "pull" (or "push") and "commit". Sometimes a "merge". With network connectivity you do not need the USB stick (in my case it is just a bit easier).

Should any of those clones/repositories die it would not be a big problem.

Note: this is not a backup solution, this is a solution to sync the machines!

They are way beyond dicks and would go to unbelievable lengths not to provide you with the service you bought. They are proactively scanning your account and will shut you down (without ANY warning whatsoever) for any media file that look suspicious (that includes mp3's you recorded yourself, as in you're the artist).
At first when they started cracking down on people using disk space they just shut down everybody that was using "too much" in their opinion (they were specifically offering 1500 GBytes space and 15000 GB/month transfer at the time - now they are "unlimited"). No questions, nothing. When customers asked they said they modified the TOS and say something like "you're not allowed to store files (!)". They also modified the TOS to say they don't have to notify you when they modify the TOS (which they had accordingly to the old TOS). And they didn't notify anybody, just shut down accounts randomly.
If you use their whois privacy feature (default on and unmanageable via web interface) they will spam your whois with advertising. They also don't seem to get what this feature actually means and insist that you own the domain which can't be true in any legal and meaningful way (yes, you are the owner in a field in their database but legally and as far as ICANN is concerned they are the owner).

The last drop in the bucket is the hidden 50000 files limit. The limit is absolutely secret and you can find about it only when you are kicked out or warned that you are above. However they would still insist the space is unlimited but the number of files is limited. And that it is for your own protection because fsck would take far too long if you have too many files. And that if you don't like it you should go away.
The idea here is only to pay, not to use what you paid for.
To put things into perspective a default installation of gallery with default plugins will eat about half of those 50000 files you are allowed. And use probably a couple tens of megs of space (keep in mind they were offering 1500GB before going unlimited which should mean for any reasonable person more than 1500GB). Oh, and people hosting linux distributions are abusers as well.
Of course they would work more flexibly than a random free provider (you get shell access but you need to fax your ID!). But between random crashes and this "anybody using is abusing" policy you won't get too far.

Stay away from bluehost.

Or if OpenSolaris doesn't feel right for some reason (e.g. hardware support), FreeBSD ZFS support is working very well these days.

was this ment to be funny? massive AES encrypted data i think is quite hard on a processor

Unison is quite stable and I use it daily to sync between Linux PCs over a network and Windows PCs via a USB key - add some flags to allow it make some decisions automatically and 99% of the time it works silently - add a cron/WindSchedule to it and it works a bit like Dropbox.

If you're willing to pay, you could use Dropbox. If you keep it under 2 GB, it's free. Anything you drag into your dropbox gets synced to their servers and then synced back down to your other PCs you have linked to your dropbox account.

If you would prefer a roll your own solution, and are willing to build a server, then go look at Novell's iFolder http://www.ifolder.com./ [www.ifolder.com]

Andy