Problems
EXT4 is soon to become the default file system in Ubuntu once 9.10 (Karmic) has been released. I’ve already been using it, but have stumbled across a few problems:
- Reverting – I moved all of my backups and vast amounts of data across into EXT4 partitions. I have since been having a few problems with Ubuntu Server 9.04, and had wanted to revert back to Ubuntu Server 8.04 LTS but was unable to do so (as it’s not compatible with EXT4). A bit of a problem as reverting Ubuntu version and file system type won’t be easy, and will take time. In retrospect, I wish I had stayed with EXT3 for 6-12 months longer until I was happy it was ok to switch.
- Windows – I still use Windows occasionally, and it’s generally handy to be able to access your files in Windows. Currently there is no EXT4 driver for Windows. From what I can remember, something like EXTFSD, will work with an EXT3 partition “upgraded” to EXT4. A cleanly formatted EXT4 partition is different though and doesn’t currently work. EXT2IFS will only work with EXT3 (and an inode size of 128)
Apart from those issues, I’ve found EXT4 to be very good, and it does seem quicker (although it’s hard to tell). It works very well for the root (“/”) partition. For separate home and other partitions though, sticking with EXT3 may be a better idea. I plan on reverting over the next month or so, and will probably stick with EXT3 until Ubuntu 10.04 or even 10.10.
One important note, if using EXT2IFS you want an EXT3 partition with an “inode” size of 128. As of Ubuntu 8.10 onwards it will format EXT3 partitions with an inode size of 256.
Reverting to EXT3
Open up a terminal. Firstly find out the partition you want to revert:
sudo fdisk -l
This will list all of the partition devices. Find the one you want, for example in my case /dev/sda7. Now enter:
sudo tune2fs -l /dev/sda7 | grep Inode
You’ll now need to backup all of your files. I had a spare hard drive kicking around to move them their manually using Nautilus. Once moved, you can format the partition. Given that the Ubuntu 8.10 installation disc onwards will format an EXT3 partition with an inode size of 256, you’ll need to manually do it yourself via command line:
sudo mke2fs -I 128 -j -t ext3 /dev/sda7
It should only take a minute or so. If you want to you can add “-c” to the command, and it’ll run a check on the inode table, but it takes aaaages. My 1TB drive took over 4 hours.
Further Problems
Under Windows XP (SP3 and earlier) both EXT2IFS and EXT2FSD will run without any problems. However, I’m currently running Windows 7 x64.
EXT2IFS will run on Windows 7 x64 whereas EXT2FSD won’t. This means I have to have an EXT3 128 inode size formatted partition. It’s all currently, just about working perfectly. I, for some reason, can’t run .exe’s on my mounted EXT3 partition in Windows 7. It looks like a permissions issue related to the EXT2IFS driver. I vaguely remember fixing something similar with Vista (ages back) but have since forgotten. It’s currently usable, but still not ideal. I’ll post once I find a fix.
Update 23/09/2009
I’ve now got EXT3 working in Windows 7 x64 without any problems.
EXT2IFS = inode 128 and not bigger. Last update was in 2008!
EXT2FSD = inode 256 is ok. And it works under win 7 x64. I’am using it right now :0)… just make it run with vista compatibility. But ext4 = no dice!!! last update was 2 months ago or something like that. So stick with ext2fsd :0)
The inode thing isn’t hugely important just yet. It’s done to help future proof the file system, but I don’t think the additional bits are used.
I prefer EXT2IFS as it’s a lot more subtle, you don’t really notice it running. Whereas EXT2FSD has a system tray icon. It’s still ok though. I’ll maybe give it another try.
I’m sure I tried running it in compatibility mode. Probably didn’t try the Vista option though. I’ll give it another try when I get a chance and update any of my posts if it works. Cheers.
Hi Robert
Once you have formatted back to ext3, can you then copy your file system back onto the partition and get going again, or do you have to reinstall?
No need to reinstall. You should be able to just start using it. In Linux you’ll need to mount it again. This article will explain how – https://help.ubuntu.com/community/InstallingANewHardDrive (scroll down to the “Create A Mount Point” heading). In Windows you should be able to add it using EXT2IFS or EXT2FSD. I prefer the former typically as it’s a little more subtle, although both are very good.
I asked the wrong question.
Scenario:
Ubuntu installed on an EXT4 partition, working fine, is main OS.
Need to switch to EXT3 type partition
So, copy all files from EXT4 partition to safe place
Reformat EXT4 partition to EXT3.
Now if I copy all the files back onto the the EXT3 partition, will I have my main OS back?