Ext4: . . . ??

[vrkalak]

I have downloaded the new Ubuntu Karmic Koala 9.10 Beta (testing)

According the Ubuntu forums the new Linux Kernel 2.6.31-11 is better optimized using an Ext4 partition.
I assume that as a result of Ubuntu Karmic 9.10, that LinuxMint-8 Helena will use Ext4?

What is Ext4 ? Lets talk about the how, why and how come of Ext4. And can our computers and the partition manager do it? And what if we don't?

I found a How-to link for the Ext4 wiki page: . . . http://ext4.wiki.kernel.org/index.php/E ... em_to_ext4

[dequire]

I use ext4 on my "/home" and "/" partitions with Mint 7. Works great.

[optimize me]

I use ext4 on my "/home" and "/" partitions with Mint 7. Works great.

+1

[rijnsma]

Does remastersys work with ext4?
I still use Mint 6 (ext3).
Some have (had) problems, I saw on the internet.

[emorrp1]

I too use ext4 on Gloria. Although ext4 is likely going to be the default for new installs, existing installs will not be upgraded (as it's a complicated process) but since we always recommend a fresh install over an upgrade it is likely you'll use ext4. Note that the ext4 in Helena will be an even more refined version than that in Gloria, so I really doubt there'll be many issues.

[rijnsma]

So, when I ask: "Does 'Remastersys' (Livecd backup of the system) work with ext4?"
You answer: "No problem!" That would be great, and quite critical to me.
Backup of the system is so important. Thanks for the answer!

[emorrp1]

Well of course remastersys will work with ext4 quite happily, from systems which can work with ext4 quite happily, i.e. Mint 7+, not Mint 6 because poor Felicia only understands ext3-

[rijnsma]

Remastersys works fine with Felicia ext3. But when I'm going to use Gloria or the next Mint (8) there will be the option: ext3 or ext4
I assume. When remastersys would not work with ext4 I choose for ext3 of course. Backing up the whole system is very important
for me. And Partimage is good, but less 'handy'.

[midas]

I am using ext4 under Gloria (64bits) for several months now and simply won't go back to ext3 anymore. Haven't experienced any kind of problems and simply love the performance boost. Just wait for Helena and one is definitly sure it is as rockstable as ext3...

[rijnsma]

And remastersys is working properly, Midas? (That is my question.)
Or didn't you try that one?

[altair4]

I was just reading the release notes of Ubuntu 9.10. http://www.ubuntu.com/getubuntu/releasenotes/910
Found this little snippet :

Possible corruption of large files with ext4 filesystem

There have been some reports of data corruption with fresh (not upgraded) ext4 file systems using the Ubuntu 9.10 kernel when writing to large files (over 512MB). The issue is under investigation, and if confirmed will be resolved in a post-release update. Users who routinely manipulate large files may want to consider using ext3 file systems until this issue is resolved. (453579)

> 512 MB? Like ISO images or backup images of partitions?

I'm kind of old fashioned, I think a filesystem should be stable even for really really big files

[midas]

Oh sorry Rijnsma...haven't tried remastersys on my system

But have downloaded and burned a couple of ISO's, without problems.

[emorrp1]

altair4: simple, stick with ext3

[opticyclic]

The only issue I came across with Ext4 was when I needed to recover GRUB.
Several bootdisks, e.g SUPERGrub and Knoppix LIVE CDs that I had around didn't support Ext4 and I wasn't able to recover easily.

Thats not to say that I wasn't able to recover once I had access to my Mint CD again.
Its just that support for the filesystem doesn't have as much coverage as Ext3

[linXea]

I wouldn't use ext4 for /. Ext3 write to disc all the time while ext4 buffer and then write. Let's say you hard reset your computer and thing's things on / haven't been written to disc just yet you may encounter some serious issues. Ext4 is a refined version of ext3 and has increased speed and I see no real disadvantages using it for media discs and /home partitions etc.

[T J Tulley]

I think I selected ext4 for / and /home partitions when I installed Helena with Windows 7 on a new Dell Inspiron laptop

Now my Windows User account wouldn't open and I had to reinstall Windows from the Dell Recovery disk - I was relieved to find that it did this into the squeezed partition (80 GB) so didn't overwrite the Linux installation as I had feared, and all my data remained accessible.

However Supergrub fails to restore Grub to the MBR, and I have just read in a forums search for Supergrub that this is a known problem. However I also read that Mint was restored in spite of that.

How, please? I need to restore Grub as Supergrub used to do - at present I can't open my Linux system, and don't want to re-install.

[Using LinuxMint-8 with Windows-7 on a laptop with 500 GB hdd, 2.2 GHz cpu and 4 GiB RAM]

Yours hopefully, -

Theo Tulley.
tj.tulley@physics.org

[opticyclic]

You should have really created your own thread rather than hijacking this one.
Anyway, if you still have your Mint CD you can use it to recover Grub.
The commands are slightly different for Grub2 than Grub legacy, but it is fairly straightforward.
There are plenty of examples available
http://www.webupd8.org/2009/12/how-to-r ... linux.html
http://www.ubuntu-inside.me/2009/06/how ... ndows.html

[T J Tulley]

Thanks a lot, Opticyclic - the second link worked a treat - although Helena comes with a late version of Grub 1, not Grub 2.

Apologies - I spotted later that this is not a Support forum, so posted again in Installation & Boot.


Yours gratefully, -

[Using LinuxMint-8 with Windows-7 on a laptop with 2.2 GHz cpu and 4 GiB RAM]



Theo Tulley.

[breaker]

You can also turn off journaling for ext4, but only if you have kernel 2.6.30 or higher.