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How To Move Your Linux Systems To ext4
LinucksGirl writes "Ext4 is the latest in a long line of Linux file systems, and it's likely to be as important and popular as its predecessors. As a Linux system administrator, you should be aware of the advantages, disadvantages, and basic steps for migrating to ext4. This article explains when to adopt ext4, how to adapt traditional file system maintenance tool usage to ext4, and how to get the most out of the file system."
reiser4?
IranAir Flight 655 never forget!
ext4fs is designed to be used in systems requiring many terabytes of storage and vast directory trees. It is unlikely the common desktop (or even, for that matter, the common server) will see appreciable performance increase with it.
Link to Ext4 entry on Wikipedia for people who aren't familar with it (like me).
Yes, Terabyte is not entirely correct according to SI, but Tebibyte just sounds lame and language is a tool, to facilitate written and oral communication.
Of course, in this case you have to balance the confusion stemming from the Tera in IT context meaning 1024 in some cases. To be honest, people insisting on the new naming, they should have come up with a sensible sounding name and promoted that. You have to remember that language, even technical language is for the people. There are lots of ways to craft a beautiful, logical, symmetrical language that no sane person would use because it just doesn't sound convenient.
Maybe a linguist can pitch in to explain why tebibyte sounds so awful?
It takes a man to suffer ignorance and smile
Be yourself no matter what they say
...who are on the lookout for a new fs to entrust with keeping their precious data: make sure to check out btrfs ( http://oss.oracle.com/projects/btrfs/ ). It's a really neatly spec'd filesystem (with all the zfsish stuff like data checksumming and so on), developed by Oracle employees under GPLv2, which will feature a converter application for ext3's on-disk-format - so you can migrate from ext3 to the much more feature-packed and modern btrfs without having to mkfs anew.
On a related sidenode: I'm very happy with SGI's xfs right now. ext\d isn't the only player in the field, so please, go out and boldly evaluate available alternatives. You won't be disappointed, I promise.
:%s/Open Source/Free Software/g
YTARY!
Step 1: Install Fedora 9
OK, all done!
Oh, please. ext2 had "undelete" capability, just as it had filesystem compression capability. Neither were ever implemented.
Hail Eris, full of mischief...
E pluribus sanguinem
Personally, I think the whole thing is a mess, and computer professionals should be working harder to enforce a consistent scheme. Unfortunately, only a minority of computer professionals seem interested in changing the status quo confusion. Maybe a linguist can pitch in to explain why tebibyte sounds so awful? I'm no linguist, but I don't think "Tebibyte" sounding silly is the real problem. I admit that I laughed when I first heard the binary prefixes. They sound lame. But who cares? "Quark" was silly when it was first coined. So was "Yahoo" and "Google" and "Linux" and "WYSIWYG" and "SCSI" and "Drupal" and so on... Silly names become second-nature once they are used enough.
I think the real problem is that people, inherently, are loathe to change. They are more apt to come up with rationalizations and justifications for doing things "the old way" rather than put in the work to learn (and code!) a new system. Sorry if this sounds harsh, but I find the people who say the binary prefixes "sound dumb" or say that "the current (inconsistent)* system works fine" are just coming up with excuses to avoid doing the work to use a properly consistent standard/notation.
Maybe you're right, and that if the new prefixes had sounded "cooler", then adoption would have been faster... but I'm not so sure. Even if true, it doesn't absolve any of us for allowing the confusion to persist: cool or not, we (geeks especially!) should have the discipline to use proper standards.
* The current system can be roughly described as: SI prefixes are powers of 10 everywhere except in computer science, when they become powers of 2. But only when referring to memory, and some data structure sizes, but not when referring to transmission rates or disk space (unless it's a flash drive, sometimes), and other kinds of data structures.
Do you think the public response would have been different had he been in a bar?
IIRC, today's PCs have high-resolution timers available that surpass the old 14.318MHz clock chip. If you can't get accurate nanoseconds out of the timers yet, they'll just round the numbers off. No big deal.
BTW, NTFS uses 100ns timestamp granularity, and it was designed when systems were almost 100X slower than today. So it had a similar amount of overkill, but that certainly doesn't seem to have had any negative impact on the acceptance of NTFS.
The whole "undelete" thing is a DOS FAT stupidity. The *only* reason why people think that you *can* undelete is that the DOS FAT file system was designed in such a way that file changes could be recovered *IF* you managed not to change the file system too much. DOS being a mainly single tasker, with the exception of the standard "indos" flag games.
POSIX was not and should not be designed in such a way that "undelete" is reliably possible. That's like saying can I unlight that match. Can I unbreak that egg?
An unreliable system that may, on the odd chance that the file structure has not changed too much, recover files from a disk that have not been over-written yet is no replacement for NOT being an idiot and being careful when you delete something.
Buy a Mac, then won't even be tempted with having a choice of something better.
ext4 is the biggest waste of time and effort in Linux. There are already good extent based filesystems for Linux. Why anyone would consider using what is an experimental filesystem for a multi TB production filesystem is beyond me.
What ever they do XFS and JFS will have way more testing and use than ext4 will ever have. I just don't get the point of ext4. It would be far more useful to fix the one remaining issue with XFS, the inability to shrink the filesystem none destructively, than to flog the dead horse which is ext2/3 even more with ext4, which is not one disk compatible anyway.
Perhaps you should try prm (pansy rm) or psh (pansy shell).
Comment removed based on user account deletion
Those features may be new to ext3, but not to the real competitors. I see nothing that might grant an edge over JFS or XFS. The real justifications will come from performance tests.
This reminds me of the recent NTFS article here, which actually suggested that since Hans Reiser is in jail and reiser4 is dead, we should consider NTFS. WTF? The ludicrousness of using NTFS as the primary filesystem is further justified in this article by its similar performance to ZFS, but both run in user-space (and are thus horrible in performance), so neither is really an option. What the heck is wrong with JFS and XFS?
Here are some real comparisons: First, Wikipedia's Comparison of file systems gets you started with a nice mapping of features. Second, a benchmarking of filesystems from 2006 which is still quite applicable (though it doesn't yet cover ext4). What we need is a comparison of EXT4 to XFS and JFS (et al), with EXT2/3 in there for reference.
Recall that the biggest reason for using ext3 is that it is supported best of all the filesystems. If all hell breaks loose, even Tomsrtbt (an ancient rescue floppy pre-dating knoppix) can fix it. Ext4 breaks this backwards-compatibility to ext2. Therefore, I see no reason to use it. One might as well use something more stable and proven, especially while we lack numbers suggesting it performs as well or better.
Use my userscript to add story images to Slashdot. There's no going back.
This suggestion is broken for a few reasons. ...
.Trash directory at the same time.
Fifth, if you delete two files in different directories with the same name, both can't exist in the
This may help (from <a href="http://en.wikipedia.org/wiki/Ext3">Wikipedia's ext3 entry</a>):
"Block size Max file size Max filesystem size
1KiB 16GiB 2TiB
2KiB 256GiB 8TiB
4KiB 2TiB 16TiB
8KiB 2TiB 32TiB
It should be noted that the 8 KiB block size is only available on architectures which allow 8 KiB pages (such as Alpha)."
The article doesn't say this explicitly enough: if you like to keep your data, DON'T USE EXT4 YET! It is still in highly experimental stage. Try it out, fine... but not as the only copy of your data.
Please.
The greatest feature of modern software is "Undo." Everything I can screw up on the computer should have an Undo-- that's what the Recycle Bin (or Trash Can for Mac users) is there for, although it's a bit more awkward than pressing control-Z.
Call it stupidity if you want, but my system files (you know, the ones that file permissions actually protect from malware) are worth approximately zero, and my personal files (the ones that malware can delete no question asked) are worth hundreds of man-hours, if not thousands, and ten times that in dollar value.
Windows Shadow Copy has an exact template on how to implement it, now go implement it.
(And yes, I keep backups, as should everybody. But there's no excuse not to use spare disk space as another layer of defense.)
Comment of the year
Sorry, but no way I'm gonna have a script that contains "sudo rm -rf" on my system...