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Ext3cow Versioning File System Now Available for 2.6 Kernel
ext3cow.com — The ext3cow file system has just been released for the Linux 2.6 kernel. You can view your file system as it looked at any point in the past. You'll never lose a file again!
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- LoonyPandora, on 10/12/2007, -0/+7Interesting project, good luck to ya!
- tinkertim, on 10/12/2007, -1/+4Trying this with Xen 3.0.5 right now :) Wooooo hooooo!
- Karrde712, on 10/12/2007, -0/+7With the addition of a TimeMachine-like front-end, this could really set desktop Linux ahead in terms of artist and other content-provider support.
Photoshop, video editing tools and novel writers would have an in-built revision system to keep track of their work and allow them to roll back changes easily, without having to save endless backups.- Bardak, on 10/12/2007, -4/+5I personally would not like the ui to be like timemachine because I find it distracting
- moniker, on 10/12/2007, -1/+4According to their website it looks like somebody already has attempted a GUI for this:
http://www.sandeepranade.com/html/ComputerScience/time-travelling-file-manager.html - adamkhel, on 10/12/2007, -5/+6How would it be 'ahead' if another OS has already implemented it? (Apple TimeMachine, Sun ZFS, NetApp, etc.)
- 1021, on 10/12/2007, -1/+5"How would it be 'ahead' if another OS has already implemented it?"
Karrde712 didn't try to compare it to another OS, you simply made up the comparison. For all we know, he could have meant it would put it ahead of it's own older self (w/o Ext3Cow). - xspinkickx, on 10/12/2007, -6/+3eww.... no time machine for linux, plx, that gui is seriously way too over the top, its like having the THX sound clip play, the lights dim, and have a laser light show every time I have to change the TV channel.......
- koick, on 10/12/2007, -0/+3@adamkhel:
I note one famous OS missing from your examples... - cosequin, on 10/12/2007, -4/+1great, but then apps would need to save on each and every edit to allow complete undo/redo. But if this filesystem uses incremental diffs then great!
Im glad Lyhnucks is finally catching up to VMS, lol :-P - ibis, on 10/12/2007, -0/+4"How would it be 'ahead' if another OS has already implemented it? (Apple TimeMachine, Sun ZFS, NetApp, etc.)"
Okay, so I can get this right now for Linux, can you point me to where I can get TimeMachine for OSX at the moment? How about we say ahead of other commonly used desktop OSs? - harlowsmonkeys, on 10/12/2007, -2/+3@Ibis: "Okay, so I can get this right now for Linux, can you point me to where I can get TimeMachine for OSX at the moment? How about we say ahead of other commonly used desktop OSs?"
Windows has it (volume shadow copy in XP). Third parties had it for Windows before that (for 9x, even), with apps such as Roxio (later Adaptec) GoBack, or Second Chance from PowerQuest.
- mournsanity, on 10/12/2007, -1/+24Holy cow!
- ostracize, on 10/12/2007, -9/+2The proof is in the pudding.
This still requires you to patch and re-compile your kernel, still requires you to install their tools to make use of such a filesystem, still requires you to manually take snapshots.
I would be happy when it does all this on a base install- moniker, on 10/12/2007, -0/+8What? Getting this functionality on a "base install" would be a function of the installer for the distribution you use asking you if you wish to format your partition with this filesystem. Your distribution would then likely also install a yet to be written utility that schedules automatic snapshots of directories or files of your choosing. The creators of this filesystem format would be responsible for providing exactly none of this. They've already done all of their hard work.
- markit, on 10/12/2007, -0/+5Thats like saying, here Balmer/Jobs I've just written this awesome program, now all your install cds need to be updated so that i can buy PCs with it pre installed.. tomorrow
It takes years for something like this to become truely stable and feature complete, and in the case of some people (microsoft) never! - ostracize, on 10/12/2007, -4/+6@moniker
@markit
Jeez, I'm not saying it's their fault. I commend them for building the filesystem.
Just saying there isn't much reason to get excited about it until it does all these things on the fly (through their implementation or through distribution implementation). - SteveMax, on 10/12/2007, -1/+5Was it submitted to the main kernel? I never liked to use "patched" filesystems, but as soon as it gets in the kernel it becomes very interesting indeed.
- gharding, on 10/12/2007, -1/+6@ostracize:
I'd say the fact that it exists is enough to get excited about. Who cares if it masturbates you while it installs itself.. it's not like it's a huge challenge to do it yourself. - bj1989, on 10/12/2007, -0/+0Straight from the site:
Some advantages of ext3cow:
• It does not pollute the name space with named versions
• It has low storage and performance overhead
• It is totally modular, requiring no changes to kernel or VFS interfaces
Which means you DON't need to patch and recompile the kernel.
- angusm, on 10/12/2007, -1/+23Advantage: no deleted file is ever really gone for good.
Disadvantage: no deleted file is ever really gone for good.
Sure, you ran PGP's 'secure wipe' over your browser cache directory ... but somewhere in your filesystem, the details of your visit to www.goatsandgirlsxxx.com will live on forever. Not that anyone here has anything to hide, of course, but still ...- dbixler, on 10/12/2007, -4/+32http://www.goatsandgirlsxxx.com
Server Not Found :(
Stop teasing us man. - jackyyll, on 10/12/2007, -6/+2Yeah and all your illegal torrent data is always there.... Not that anyone here would ever download something illegally... I mean it's not like we support ripping of HD-DVD's here or something.. pff
- RuddO, on 10/12/2007, -0/+3Simple to solve. Mount your browser disk caches in a different, non-versioned, non-logging file system such as ext2 or (ykes!) vfat.
- cosequin, on 10/12/2007, -0/+2it will be registered soon I bet
- thekidder, on 10/12/2007, -0/+1From TFA:
"Ext3cow was designed as a platform for regulatory compliance, and has been used to implement secure deletion, authenticated encryption, and incremental authentication"
It appears as though it supports secure deletion somehow. - dukeinlondon, on 10/12/2007, -0/+2Just as you can create snapshots, you probably can delete them too...
- macoafi, on 10/12/2007, -0/+1our illegal torrent data is always there.... Not that anyone here would ever download something illegally... I mean it's not like we support ripping of HD-DVD's here or something.. pff
^^^
Hey now, maybe we're not supporting ripping HD-DVDs. Maybe we're supporting being able to watch our legally bought HD-DVDs on the OS of our choice. I don't use DeCSS to copy regular DVDs. I use it to watch them on my laptop. Same thing. - Izzie, on 01/21/2008, -0/+1you know what's great about documentation ? you can actually read it instead of making things up. From ext3cow FAQ:
What about temporary files?
Files that are created and destroyed in the same epoch, i.e. no snapshot is taken, are actually deleted. This helps prevent useless temporary files from getting captured in the past, minimizing overhead.
How do I really delete a file in the past?
Currently, there is no mechanism to do so. However, one existed in the 2.4 version of ext3cow, so it’s just a matter of time until it makes its way into 2.6. Check the Bugs and TODOs page for planned enhancements.
- dbixler, on 10/12/2007, -4/+32http://www.goatsandgirlsxxx.com
- pivovy, on 10/12/2007, -2/+3Something like this has to be space-consuming or at least depend on free space available (so it could restore the files that haven't been physically overwritten). I believe for those with small HDDs (like on laptops) this is not an option...
- 1021, on 10/12/2007, -0/+4You ever heard of incremental saves? Basically the principle comes down to the fact that you save all versions of a file within the filesize of the largest size that it ever has been + marker database for different revisions (which won't get very big). This won't be as wasteful with harddisk space as you may first think. For example, are you telling me that I can't run a very large SVN repository on my laptop? no, I definitely can. Although the instances of use is completely different, the fundamentals remain the same.
- BlackAdderIII, on 10/12/2007, -0/+1Indeed 1021 - I've svn'd my home directory before to achieve just the same effect - hell, 3 weeks after I was being mocked by a friend for doing this, Linux Format ran a feature on doing just that and he tried it, heh.
@pivovy - basically, incremental versioning like this saves the differences at each tick, not a new copy of each whole file.
- benplaut, on 10/12/2007, -1/+1While this is really cool, I'm still trying to think of a situation in which a local SVN wouldn't be more appropriate. Really, this is //too// powerful.
- t0ny, on 10/12/2007, -2/+12It wont work. I put windows xp on it and cant get it to turn back into Windows 3.1.
- Heretushi, on 10/12/2007, -4/+1I fail to see the difference between this and make a copy of the file myself to another location and make sure to put the timestamp in the title of the file. Obviously, if there is automation in the process, it's good, but the concept can be done right here right now using a backup software of some sort. Using this system, you would have a backup snapshot of all your documents, filed by age and/or modification (based on the snapshot criteria), that is stocked on the same physical support as the new modified document. It seems to me that it is both space consuming and a less than ideal backup solution in term of data security. Can someone explain the advantages of building a whole filesystem around this idea?
- 3Den, on 10/12/2007, -0/+1The advantage is that with a very acceptable resource footprint, you can have very frequent snapshots of everything. Copying all the files is hundreds of times slower than this, and will double your used disk space every time you do it.
This doesn't copy the files.. it takes an inode table snapshot.. and inodes would be preserved rather than recycled if some data is still in a snapshot.
This does NOT replace offline backup.. it's not an alternative to that.. it's just a very handy feature.
- NetApp Filers have done this for years; Windows servers can also do it. I would imagine so do many other server-class systems. - fryguy1013, on 10/12/2007, -0/+1You're right, it's not automated.. which makes it inconvenient. The other major thing is that your way creates a lot of files on your pc, which is the biggest problem. Benefits of doing it with ext3cow is that the file differences are very efficiently stored. Instead of having 10 entire copies on your hard drive, there is only 1 + the content of changes between versions. Also there's the whole 'meets regulatory guidelines' to provide an auditable trail thing too.
I'm with another poster though, in that I can't think of why this would be better than svn (although building a SVN client on top of this would be neat). - Yggdrasil42, on 10/12/2007, -0/+3SVN doesn't allow you to use it interactively while Ext3cow will. You can open the snapshots with programs and even run a shell that sees the files as they were before.
Furthermore, SVN doesn't provide secure deletion and other features of this filesystem.
- 3Den, on 10/12/2007, -0/+1The advantage is that with a very acceptable resource footprint, you can have very frequent snapshots of everything. Copying all the files is hundreds of times slower than this, and will double your used disk space every time you do it.
- VinceNoir, on 10/12/2007, -1/+7The concerns about privacy are unwarranted. For one thing, you don't have to use it at all if you're a home user. And if you're at work, then you really shouldn't have anything on your system that would get you into trouble, now should you?
- DarkStalker, on 10/12/2007, -0/+1Hmm... this was one of the reasons I was waiting to switch to Reiser4... just when I thought I would hardly ever use ext3 again.
- jonr, on 10/12/2007, -0/+2
I don't get it. How do I know what versions are available. The screen grab is just confusing. Does my folder fill with files with extra @123832405 characters? Do I have to know the exact sequence?
# snapshot
snapshot on .: 102458745
# echo "some thing" > foo.txt
# cat foo.txt@102458745- jmacdonagh, on 10/12/2007, -0/+2No, the directory still has the one file. I'm sure there is a built in command that will show you the different versions of each file.
- jacekpoplawski, on 10/12/2007, -0/+2But how does it work? What should you do when the disk (partition) is full?
- BigSlacker, on 10/12/2007, -0/+0Just like ZFS...delete some snapshots to clear up space.
- cosequin, on 10/12/2007, -5/+2Lyhnucks is finally catching up to VMS, lol :-P
- barbapapa78, on 10/12/2007, -0/+1At first I thought that you could go back in the filesystem at any second you liked and you would see it as it looked exactly them, but apparently it relies on "snapshot" being run at certain intervals or at a point when you decide to make a snapshot. This makes it kind of just like svn as someone mentioned earlier.
But how big performance hit would it be to let cron run "snapshot" every second ? You might for example just mount your own home directory using ext3cow and not the entire disk.
Or did I misunderstand this "snapshot" thing ?
Surely it looks convenient anyway.- neko, on 10/12/2007, -0/+1The snapshot thing appears to be just updating an epoch counter on the disk. So there is pretty much no performance hit at all - new blocks that are written to disk just inherit the new epoch number.
- BigSlacker, on 10/12/2007, -0/+1Hey, it's like using VMS again. I can see some good uses for it although most applications use a database on not a filesystem for storage.
- BigSlacker, on 10/12/2007, -0/+1Ah, it is snapshot based on not a real versioning filesystem. It's still useful but not quite as much. I occasionally use snapshots in zfs for things like upgrade backouts.
- dhonn, on 10/12/2007, -0/+1copy on write is awesome. Im going to use this for my ubuntu server. I've been thinking about using a versioning system for some time now but this one is more practical to use.
- kaba06, on 10/12/2007, -0/+1There is a nice tool called TrackMyFiles that does automatic file versioning. Great for important documents.
- ray73864, on 10/12/2007, -0/+0Windows has had this for a while now, it is called 'Volume Shadow Copy' and when the service is set up, you are able to right click on a file and retrieve any earlier version.
The problem with it is that i believe it only works if you have your machine attached to a DC or a File Server.- BigSlacker, on 10/12/2007, -0/+0I've only heard VSS in the context of system backups. Our backup software uses it. It also apparently depends on the application to support it. Applications compiled pre-XP or 2003 don't have support.
- BigSlacker, on 10/12/2007, -0/+0I've only heard VSS in the context of system backups. Our backup software uses it. It also apparently depends on the application to support it. Applications compiled pre-XP or 2003 don't have support.
- jlebrech, on 10/12/2007, -0/+1Where's the moaning from the mac fanboys?? It's like Leopards timemachine isn't it?
- Schalken, on 10/12/2007, -0/+0I agree a time-machine-like interface would be way over the top. A simple option built into Nautilus would be desirable. The file system should enable other applications to use its functionality, for example, get songs back that you deleted in Banshee.
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