Arch Linux

hermansen

Member

Registered: 2008-11-10

Posts: 7

Re: ext4 without journal?

You can read this one http://robert.penz.name/137/no-swap-par … -on-a-ssd/

scrawler

Member

Registered: 2005-06-07

Posts: 318

Re: ext4 without journal?

from http://kernelnewbies.org/Ext4#head-be74 … 64cb9beb1e

NOTE: At least in debian-derived distros, including Ubuntu, converting your filesystem to Ext4 when using a initramfs results into a non-booting system, apparently even when you enable the "ext4dev compatibility" option". The problem is that the fstype klibc utility detects the ext4 filesystem as ext3, and tries to mount it as ext3, and fails. The fix is to pass the "rootfstype=ext4" option (without the quotes) in the kernel command line.

I started out with ext4 and it boots--but it didn't boot when I removed the journal--think this will allow it to boot?  I'm a little nervous to try it.

big_gie

Member

Registered: 2005-01-19

Posts: 637

Re: ext4 without journal?

I would guess it should not harm the system. But then you can never too safe.

Can you boot from a live cd/usb and see if you can mount the fs there? Maybe running a fsck?

scrawler

Member

Registered: 2005-06-07

Posts: 318

Re: ext4 without journal?

argh.  I tried it, it wouldn't boot, so I put the journal back and I'm back in business.  I was nervous for a second.  I hope that the journaling doesn't wear out this sd card too soon--I put ext4 on it counting on being able to turn off the journal.

big_gie

Member

Registered: 2005-01-19

Posts: 637

Re: ext4 without journal?

Thanx for the link hermansen. SSDs wear are maybe over-estimated, but I still prefer to be on the safe side until real world tests have been made. I think it should mostly depend on the use of the drive. "Normal" use should not be a problem, but then I often go way more then normal use...

@scrawler If you're scared of it, you can always try ext2. I used that before ext4 came out for my /home, and still using it for / without problem. Up to now, ext2 has even been more safe then ext4 on my home. I lost a simple script after a kms freeze due to writeback on ext4 (see http://lwn.net/Articles/322823/ ) which got me really angry... Even though ext4 has a journal and ext2 does not, ext2/3 flush data back to disk more often, making sure data is on disk. Now if the machine freeze, I try to wait at least 30 seconds before forcing a shutdown...

Tera

Member

From: Finland

Registered: 2007-01-25

Posts: 81

Re: ext4 without journal?

argh.  I tried it, it wouldn't boot, so I put the journal back and I'm back in business.  I was nervous for a second.  I hope that the journaling doesn't wear out this sd card too soon--I put ext4 on it counting on being able to turn off the journal.

I run ext4 (with journal) on my Acer Aspire One's SDHC card. I use it to store my $HOME, which contains kernel sourcecode and lots of other stuff. I am compiling kernels on daily basis, then removing the source, after which I again unpack the sourcecode and basicly start from scratch. I would estimate I have done this already over 100 times with this single card and it's still kicking. In my opinion, you're in safe if you compare average use (to which your usage probably counts to)  to something I do with my card.

Last edited by Tera (2009-05-11 19:17:19)