Slashdot Mirror
Organizing Data Across a Heterogeneous Net?
angst_ridden_hipster asks: "Like many people, I have a bunch of machines I use regularly. These include Linux machines, BSD machines, a Mac OS X machine, and a Windows machine. These machines are on a number of networks. All have internet connectivity. Some of them are always powered on. A few of them are not. Obviously, I have a bunch of accounts. And, it goes without saying, I have a bunch of data. What are the best approaches to sharing data? I want to be able to securely access my home data while at work, and from one machine to another, etc. Opening ssh terminals is the approach I have traditionally used, but I'm beginning to wonder if some mirroring software (e.g., Unison) might be in order. It'd provide the function of backups, as well as guaranteeing availability. Would it be wiser to tunnel nfs over ssh? Or is there some better option?
Assuming I actually start mirroring data across multiple machines, I'll need to organize it in a portable taxonomy. This is almost easy, since I use cygwin on the Windows machines, so I can assume a standard Unix-ish directory structure. But this gets more complicated when there are scripts or other code involved. What about application/platform-specific data? How do other people organize their data, anyway? Are there any useful standards? I'm hoping people will describe their approaches, and why they think they're (not) the best."
Without knowing more about the type of data you're storing, I would recommend putting it in a database. I like PostgreSQL 7.x myself.
For the software, I would organize it in a directory structure and use rsync+ssh to mirror it as needed.
For backup software, use Amanda.
For file sharing, use Samba.
'Nuff said.
I've been thinking of tackling this problem for awhile too. The best I can do is that you abstract the 'directory' (the list of what you have), for replication, accessibility (with convenience as the priority, especially). Then, when you need to do something with that data, your directory knows where it is and how to get at it. In this case, the convenience of accessibility isn't as crucial, and thus the need to transparently glue all these platforms and protocols, etc together isn't quite as important.
For me, I'd just like a top down, real time view with convenient access of what I have - getting it anywhere and anytime isn't quite as crucial for me.
Maybe you make a little daemon that can monitor your data respositories at several sources and 'merge' the data listings at a central source for publishing to multiple sources again?
"Old man yells at systemd"
IBM has released Transarc's AFS as OpenAFS (http://www.openafs.org). Don't know if that is what you're looking for, but it is pretty nice. It's also portable, so it runs on various unices as well as Windows. Most can be found as binaries if you don't want to roll your own.
AFS is an NFS style implementation though, so you would have to save your files onto a special mount.
Wealth is the product of man's capacity to think. -Ayn Rand
"kio_fish is a kioslave for KDE 2/3 that lets you view and manipulate your remote files using just a simple shell account and some standard unix commands on the remote machine. You get full filesystem access without setting up a server - no NFS, Samba,
It works through SSH, so everthing is encrypted.
I use this with the konqueror file browser, but all KDE apps can transparently access files on remote hosts using this amazing utility, which required no special setup on either end, at least on my systems.
Solved all my data sharing needs - and andromeda solved the rest :)
sig sig sputnik
What you need is something known as a "server." A server is where you can store all your files, and in some cases, account information.
With the right kind of server, it can do AppleShare, NFS, and SMB, allowing all your other machines to mount the shares and make them appear as local drives. This keeps all your data in one place, allowing for easy backups, and also makes it easy to get at the same files from any computer.
My personal preference is a Linux computer with several cheap IDE drives each on their own IDE controller (no slave drives). The drives are configured as software RAID 5 and ext3. Regular backups are setup through cron to a tape drive. Samba handles file sharing, printing, roaming profile, and PDC duties for Windoze. Netatalk 1.6cvs handles file sharing duties for pre-OSX systems. NFS is used for file sharing to *nix systems. The only thing I'm missing is a NetInfo daemon for Linux so it can act as a complete configuration server for NeXTSTEP, OPENSTEP, and MacOS X systems.
I'd say what you need is an internet-enabled file system. Some might say NFS, and that seems like a fine solution.
On the other hand, if you have a computer that is always on, that can run Apache, you can have your own personal WebDAV server instead. Simply install mod_dav, and access it through mod_ssl, and have a secure web-based filesystem.
Better than NFS, you can mount it on Windows (through web folders), Linux (through davfs) and Mac OSX (through the native DAV file system client that is designed to run with iDisk).
NOTE: I work for Xythos software, and we make an enterprise-level WebDAV server called the Xythos WebFile Server. It's significantly more expensive than free, and we run in-house copies of the product (y'know eat your own dogfood), so that's where I keep my shared data, but if I didn't, I'd have mod_dav running right now.
I have twelve computers in my apartment and use all of them for something-or-other. Several are just test machines but even with those, I used to run into situations all the time where I saved something on one machine and forgot to do anything with it.
:)
My solution was to write a series of little scripts to copy data from common share points on each machine to a large, central data store, and into a "backed-up" directory on the workstations. Presently my central data store is 600GB of IDE disks in a RAID1 array (10 disks, total). If I lose the central fileserver, all my data, and the scripts needed to recreate the information in that 600GB is sitting out on my workstations
It's kind of a brute force approach, but it works OK. I'm not sure how well it would work for non-local systems, though.
I'm sure there are better ways to do what I do, too, but it's nice to have a single place to look for my MP3s or whatever, while knowing they're backed-up in multiple locations as well.
-- I wanna decide who lives and who dies - Crow T. Robot, MST3K
first of all, seperate your home life and work life. Then seperate the data. I understand that once in a while you need data from one place at the other, but avoid those situations.
At work: that is IS's problem. Store all work data on the work machines, and make IS do the backups. Use SSH, or other VPN when you want to work from home. Compile (or whatever) at work as much as possible. If you have data that you need on the road, get a laptop or PDA for work, and synchronize that when you are at work.
At home: set up a linux box (a 386 is enough, though you might want more) with a big disk, a UPS, and a network card. Put it in a closet or on a shelf. Install SAMBA, and Netatalk. with NFS built in (though there is better than NFS if you look, nfs is there) Use one loging for all machines.
Laptops are a problem, because you often want to use them where you can't get to the network. The first solution to that problem is 820.11. Use it at home, and look for open access on the road. With good VPN (ssh+nfs) you can get to your network server from many places. I manually synchronize only the files I need, but my laptop is rarely used outside of 802.11 areas, if you travel often, then you might need more. (CODA? AFS? )
Now this is not totally fair, since it implies a pointy haired boss situation. All it really means is that that you would would have to have a better definition of the problem.
What it seems that you really need is an application, a database, that would constantly monitor in realtime the status and availablility of your various resources. This would tie into your other dataservices so that when you do a query on "XP sourcecode", or whatever, one of the result you get is from this resource monitor database saying that "the resource is offline" or "the data is available, but you don't have access rights", etc. depending of the resource status, and other realtime situations.
It occurs to me that clever design of the database may be able to do the resource availibily query in advance of the actual access of the data, so that you do not get a crash or whatever if a child record or whatever is unavailable.
Currently, I do not know of any tool that does this, although obviously this is not my area of expertise.
"It is a greater offense to steal men's labor, than their clothes"
Unless you want to share your data with lots of 'friends' you just haven't met yet.
NFS is used very often to mount home directories. But what is stopping someone from unplugging the workstation, plugging in a linux laptop with the IP of the legitimate workstation and mount the share, "su - user", and voila, you now have all the user's files.
That's just the simplest way. The problem is that most NFS implementations don't have *any* authentication except for IP authentication. So so other DNS attacks would work as well.
I am surpised that the most widely used network file system implementation for linux and most posix OSes has no real authentication. There *has* been authentication built in the protocol since version 3, but last time I checked, it was not supported on the linux. I was told by one guy working on the project that the problem was that there's no crypto in the kernel.
I used secure NFS on Solaris 8 for a while but I constantly lost the mounts. That but be fixed now, I don't know.
Use AFS, CVS, rsync, intermezzo, or something. But I would stay away from NFS.
Based on upvotes, Ageism is the only "-ism" Slashdotters care about and think isn't SJW
Yep. Unified access to e-mail via IMAP is definitely the linchpin of a good arrangement.
I've been trying to deal with the same problems as you for several years. I have a Mac running Mac OS X, Windows PC, Linux server, and a NeXT around my desk. I have two large hard drives. One is in the Mac and that holds my home directory, and the Linux machine has all my MP3s. My home is exported via NFS and is mounted on the Linux box and on the NeXT so I always have live access to my files. The Windows box only does my TV program and Kazaa, so I'm content to simply have it use FTP to copy files back and forth (I haven't found a decent Windows NFS program.)
It all gets the job done, and it all works smoothly. Printing is done by IP printing to my big 'ol LaserJet. All the mail is kept either on my server at school, or on the cyrus server on the Linux box. It's a delight =)
There should be a moratorium on the use of the apostrophe.
Max V.
NeXTMail/MIME Mail welcome
Use the excellent rsync from Paul Makerras (of pppd fame) and Andrew Tridgell (samba team) in combination with OpenSSH and SSH for windows (both based on Tatu Ylonen's work; OpenSSH is maintained by and expert team including Markus Friedl and the recently monkey-cracked Dug Song, among others).
Set up your accounts to rsync-upload changes to whichever server is most secure when you log out, and use a cron job on that server to rsync-download to all the other servers nightly. You can make a tar backup part of the system also.
You will have to remember what's going on so you don't modify the same file differently on two different systems within 24 hours. If you want to overcome that shortcoming by making this work on an immediate sync basis rather than periodically, you'll need something like SGI's fam (included with recent linux distros) to trigger the updating processes.
You should already be 90% there if you have your ssh keys set up for passwordless login. Passwordless PKI logins are not significantly less secure than passworded logins in most situations (granted hostile system management can get you, but the BOFH can trojan your login anyway).
Lots of people use this technique to sync CVS trees over slow links. Rsync is very efficient for that kind of thing (large volume of files, low number of changed bytes).
First, I try to adhere loosely to the FHS for ideas on overall organization. Even though it's mostly intended for POSIX systems, following their philosophy will really help you separate your data from your platform-dependent program files and libraries.
Most of my important stuff goes on the Linux server in /home (on an IDE software RAID1). However, I try to limit files in here to stuff that's absolutely essential to keep the size down. I occasionally mirror this offsite to my friends' servers with rsync (with the private stuff pgp encrypted). I try to make browser caches, etc. symlinks to dirs in /tmp . Try to keep only the stuff you created yourself in here.
I keep media and downloads on a plain partition under /home/ftp/pub (which is also symlinked from the http document root). That way, all my computers can easily get access to music and installers and junk.
Samba helps win32 boxes access the /home and /tmp directories.
NFS exports /home to the other UNIXen, as well as /usr for the other machines with the same CPU arch. It should be acceptable to export /usr/share to other UNIXen with different architectures.
I'd like to set up CODA, since it seems to support more different kinds clients than Intermezzo. These support disconnected operation and are good for laptops. For the meantime, I just use rsync to mirror home dirs onto my laptop, though (and just keep track of stuff that I change on the road manually :/ )
No thoughts on how to combine everything into a distributedFS so you could have parts of, say, a music archive living over several machines. There are several projects for Linux-only (PVFS) or Win32-only (more advanced network-neighborhoods). I'd say your best bet for convenience is just to make sure everything is visible from your one server and reexport it from there (invest in a switch so it doesn't deadlock your network). Until better DFSes exist, though, I think you'll get better performance and less confusion from running everything from one beefed-up server with a RAID (or two if you want failover).
Here's my situation: I have a dual-booting Linux/Win98 machine at home, a Win98 laptop, a Linux server sitting in some network in a galaxy far, far away; and a bunch of other computers around the world.
At one point, managing all my data (I would change a bit here, and a bit there, then try to copy and synchronize by hand) was manageable, but I got real tired of it real fast. I considered putting together a CVS server, and then synchronizing that way, but it's really overkill and not a very user-friendly solution anyway.
Enter Unison. Now I just have a few directories designated as shared, and they get synchronized by Unison automatically. At home, my data is on a FAT partition, which is accessible to both Linux and Win98.
The good thing about this is that since I synchronize with the laptop when I'm connected, I get to use my data even when I'm on the move - not so with NFS. And I get free backups as well - I do have roughly 2Gigs of data, which would be a hassle to backup any other way. Besides, if I took tape backups, I would have to manually carry them off-site in case of a fire; now Unison takes care of backups to and from my remote machines.
This works well for me to keep about 30 accounts in sync, most of them just get a minimal checkout of my home directory (5 mb or so), while 3 or 4 get the whole home directory and rsynced files (5 gb). The CVS repository is about half a gigabyte in size these days.
Once something that allows proper file rename tracking, like subversion, comes along, I plan to stop using rsync alltogether, and just check all the files in.
As has been noted elsewhere in this thread, one of the key things is coming up with a consistent directory structure and sticking with it.
see shy jo
Okay, you *could* use some form of networked file system, but a) your laptop and other machines would need to be connected to use it, and b) I hope you are willing to fight to get a good implementation to work, and c) I hope you aren't playing with big files
I use rsync. I have ~/Makefile, 'make sync' works wonders. Here's the contents:
On the laptop:
Works like a charm
Barclay family motto:
Aut agere aut mori.
(Either action or death.)
This is not a Fugazi
He-he, nice way to bring attention to this news item.
I'm not really sure what type of work your doing where you need access to your files... I can relate my knowledge on dealing with unison over the past year though.
I do a lot of back end web development. As such I usually like to copy the entire site down to a local machine, work on the system, upload to a test machine, test, and then move to a development machine. Unison has made my job a lot easier than it using a bunch of ssh scripts since unison automatically checks for changes and only copies over files with changes.
A sample script is as follows:
From my local file system $HOME/web/(website) I execute the following script
unison -auto -batch include ssh://user@somehost.com//www/(website)/include
unison -auto -batch www ssh://user@somehost.com//www/(website)/www
This script pulls all my programming work in include and the website accessable files www to my local system... I then work on the files and upload using the following script
unison -auto -batch include ssh://user@testhost.com//www/(website)/include
unison -auto -batch www ssh://user@testhost.com//www/(website)/www
I then check the coding and on the test host, when I get it to the point I want I upload it to the production machine...
If I have problems on the test host, I can go in and remove all files on my development system and pull a fresh copy of files from the live site...
Since I don't need to program and compile on different systems, just uploading the the test and production machines it works well.
Recently I took a trip and did not have access to my local system. I was able to borrow a windows system and after installing putting, winscp and unison I was up and running within 10-15 minutes at the remote site, which allowed me to get back to work.
The problem with using a remote mounting system is that you have to maintain network connectivity while working on files, not always an option, plus you are working with the live production files...
So basically I use unison just like a cp command except that it does not copy files that already are synced between systems and it automatically keeps my permissions sync'd as well.
Hope that helps
/* TODO: Spawn child process, interest child in technology, have child write a new sig */
I keep all the porn in a seperate directory. That seems to work pretty well.
I agree with you. Your question though, was overly general.
.bashrc, environment, ssh directory, pgp keys, etc.
.bashrc .bashrc, put specific things in the separate files.
.cvsignore to make sure it only manages the files you want it to. .emacs macro, or shell prompt tweak? Edit one account, cvs commit, cvs update the rest.
There's really three (or more) different separate data issues that you have to deal with.
Like most, I have many accounts, and just manage them on the fly. My data is retrieved manually when I need it. SSH (and scp), VNC, etc. This usually does the job.
Not the easiest way to do it. Especially when I recently changed jobs and had to setup new data and profiles - I thought, there must be a better way to do it.
So, here's a breakdown of the problems, and suggested fixes.
Break it down into 3 separate sets of data:
1. Profile data - Your shell scripts,
2. Daily Documents - My Documents folder, data directory. Limit this to stuff you need in ALL locations (though you could have a personal and a work version...) and on a regular basis.
3. Archived files - Infrequently used, but you occasionally need to access them from various places.
Then, the problem becomes much simpler. Instead of a grand scheme to manage all three of these at once, you have three smaller, simpler problems.
Here's my suggestions:
1. Profile info - Wasn't originally my idea, but the best thing I've found is to use CVS to manage the files. You'll also have to setup your shell scripts to detect the OS / machine you are on and run OS / machine specific versions.
For example:
Detects OS, runs ~/.profile.d/linux, ~/.profile.d/win32, ~/.profile.d/macosx, etc.
Detects hostname, runs ~/.profile.d/hostname.
Put core stuff in the
The rest, usually doesn't change.
Add it all to CVS on a personal server. Then just checkout to each account you have. cvs update will keep it up to date if you change the master copy. You might need a special
Then, you have the same profile files on all of your machines. Got a new
2. Daily use Documents. This is a mix. Perhaps you could use a separate CVS repository. Or, use rsync and rdiff type backup sync programs. The key here is to keep this to a minimum. How much to you really need, and how much *must* be in sync between all your machines at all times. Again, this is fairly easy for a small number of documents, so don't let it get out of hand. If you don't use the file all the time, and don't need to maintain changes, then push it to archives.
This is the issue that most other posts address, so I won't get into too much detail. All those solutions are much easier with a small number of documents.
3. Archived files. This is probably what you were really asking about with regards to NFS and sharing files. These are the files you need every so often, stuff like your mp3 collection, downloaded software, extended (non category 2) documents, and the like.
For these, it depends on your setup and level of network access (the speed is important too). rsync might work if you need a locally cached copy, but this is much easier if you leave it in one place. Setup a gateway on your home network with IPSec or PPTP. Or, find WebDAV or some internet accessible filesystem you can use (NFS or SMB even, depends on your security needs). Then, connect to the central repository when you need these files.
This can be large, but keep it so that you don't need to synchronize frequently, and preferably only in one direction. You listen to your mp3's, but you don't change them frequently. Same with your downloaded tar/zip files of software you've collected. (Face it, having a single directory with cygwin, mozilla, etc - all the software you have installed at each location - is much easier than finding and downloading them all from their various sites each time.)
Or, for these files, if you really don't need them all the time, leave them on the central server, and scp them when you need them.
--
So, that pretty much covers it. I hope these suggestions are useful. There comes a time where managing it on the fly just gets too cumbersome. (You'll know that time - it usually happens right after you wipe out some vitally important data because you didn't synchronize the files.)
Beyond this, you can always add all kinds of stuff. Some examples: ACAP (a configuration file server, I use it with mulberry, my IMAP client. It lets me set preferences), Kerberos for common authentication, LDAP for an address book or netscape roaming profiles, the list goes on and on.
What would be nice is a set of scripts to help manage this.
Imagine, getting a new account and typing "pullprofile", and having your environment and data all retrieved, pulled from your central server. Then you could have login and logout scripts to synchronize the data, or just manually (possibly remotely if you forgot to sync before you left work) run them. A cron job to synchronize the big data store overnight.
I'll keep dreaming, and keep looking on freshmeat and sourceforge for a project like this. Maybe one day I'll get up the energy to start it myself, but don't count on it.
;-)
~Jonathan
This response is dead on. The original asker needs a file server that speaks multiple protocols. Once you have a server, it is much easier to create the necessary ssh or ssl tunnels that you need for total security.
Trying to maintain coherency of data via replication across multiple machines is begging for trouble -- this is a hard problem that to my knowledge has not been solved in a clean, cheap way.
If you want to use NetInfo for Mac OS X, create a new port from the Open Darwin sources. There's a port of an old NetInfo server module for Linux floating around, but it's not what I'd call up to date.
A better choice would be to use OpenLDAP, as Mac OS X is designed to pull directory service info from an LDAP data source. Windows systems can also pull from a LDAP, as can Linux and *BSD and Solaris and so on.
--Paul