Comments on: Fun with Linux: The Existential File System

By: Webs

Webs — Wed, 14 Nov 2007 16:03:21 +0000

LOL Greg!!!

By: greg laden

greg laden — Wed, 14 Nov 2007 15:35:37 +0000

What’s goint to happen when Mac comes out with Bobcat at the same time that Ubuntu comes out with Bitchy Bobcat….

By: Johnny Vector

Johnny Vector — Wed, 14 Nov 2007 14:30:33 +0000

Dammit! I told you I can’t keep these cats straight!Probably because the new box doesn’t have any cat on it, just a big X and a fakety-fake swirly galaxy. Yeah, Leopard is what I mean.Posting from 00:19:e3:d4:53:3cCrap! Now I’m a MAC troll.

By: Webs

Webs — Wed, 14 Nov 2007 13:04:18 +0000

Leopard is the newest one if that is what you are referring to Johnny.Crap! Now I’m a MAC troll ;)But anyways, Time Machine is just another example of taking an idea in Technology that already exists and making it easy to understand, use, and making it practical. As with nearly all Apple features.

By: Johnny Vector

Johnny Vector — Wed, 14 Nov 2007 11:39:58 +0000

The spiffiest use for hard links has to be the Time Machine feature in OS X Jaguar. (Jaguar, right? Lessee, Panther, Tiger,… yeah, that’s the right one. Getting hard to keep all these cats straight.)Each snapshot in Time Machine contains your entire disk (or, the part you have chosen to back up). But for files that haven’t changed since the previous backup, it just creates another hard link to the already-copied file. So you end up with a given file being shared between dozens (or hundreds, eventually) of different hard links in different directories.Gives the space savings of only copying changed files, while making each backup an actual complete copy of your disk at that point in time. Sweet.Yes, I’m sure this has been done before, but perhaps not with such style. Or anyway, marketing.

By: Greg Laden

Greg Laden — Wed, 14 Nov 2007 09:43:36 +0000

Webs: You are absolutely correct!The confusion here … and it is confused in the literature, this time it is not my fault 🙂 (not this time, anyway), is that “file system” can be and often is applied to two different things. One is the way in which files are managed on the hard drive (like ext or NTFS, not what I was talking about) and the other is the way in which the system handles files. What I wrote in my post applies to ext*, NTFS, etc. …. there is no difference. Thank you for reading my post carefully and pointing out this issue.I could have said something like “the way Linux handles files”The problem with at topic like this is that any one small concise piece will always have many unconnected threads …And yes, Troll Kevin told us he was an expert but revealed the truth when he bitched at me about how NTFS does this too, etc. He is utterly confused. Not well trained, I suspect. But well meaning, I’m sure.

By: Webs

Webs — Wed, 14 Nov 2007 09:22:20 +0000

For me the only confusing thing would be mentioning “Linux Filesystem”. There really isn’t a Linux filesystem, because you can use nearly any filesystem you want on Linux, ext2, ext3, RiserFS, JFS, etc… Likewise, on Windows 2000 you could use NTFS or FAT 32. Linux the OS knows how to handle symbolic links and hard links, but the filesystem chosen doesn’t really care as the OS tells the filesystem what to write.Maybe that was the confusing part to Kevin and sorta for myself? I think I understood your underlying message though, and I hate to sound like a Linux troll. Besides my gripe above, it was a well written post about Linux. I can’t wait to read the next one!

By: Greg Laden

Greg Laden — Wed, 14 Nov 2007 08:58:22 +0000

Kevin,Thanks for the comments. Nothing I discussed regarding Linux file systems has to do with the web. But the way linux file systems work does have important historical and pragmatic implications. I think its OK for me to mention this without giving the details (if you read carefully you will see what I mean).I did not bother to mention that many modern file systems like NTFS have been playing catchup to the Unix file system, thanks for bringing that up.NTFS is probably the worst thing that ever happened to file systems ever, anywhere. I’ve never in my life lost data to a hard drive except one using NTFS.In any event, thanks for your expert comments. Always appreciated.

By: kevin

kevin — Wed, 14 Nov 2007 08:39:04 +0000

Greg -As a fairly expert linux and windows developper, I think this post is pretty misleading and confusing. There is nothing particularly special about linux’s handling of hard links (multiply-named files, as you describe them) or soft links (aka symlinks, i.e “symbolic” links, not “simulated” links). NTFS 5 has both, and other than the earlier windows filesystems which only have soft links, most every modern filesystem has both as well. And they are hardly used at all in practice… most users get along fine without *ever* explicitly creating a hard link.And none of this really has anything to do with the web, or with security, or with viruses. If anything, the only real difference for the web is that windows treats file names case insensitive while linux treats them case sensitive.For security, one could easily argue that traditional linux-style permission bits (ugo/rwx) are pretty pathetic, cumbersome, and limiting, compared to windows-style ACLs.-Kevin

By: Greg Laden

Greg Laden — Wed, 14 Nov 2007 07:45:59 +0000

Janne, thanks for the correction on sym vs. sim. I’m making it in the post.I usually try to mention when I post on Linux tech stuff that no one should ever consider me an expert. If you follow my instructions very very carefully, you will ruin your afternoon.