ext4 and data consistency [LWN.net]

ext4 and data consistency

Posted May 22, 2010 20:36 UTC (Sat) by nix (subscriber, #2304)
In reply to: ext4 and data consistency by anton
Parent article: The Next3 filesystem

Sticking with 2.6.30 is foolish. Bugs are fixed in ext[34] all the time, sometimes data loss bugs: by sticking with 2.6.30, you're depriving yourself of all of those.

(btw, you can put mount options in the superblock, and avoid modifying /etc/fstab.)

(Log in to post comments)

ext4 and data consistency

Posted May 23, 2010 11:44 UTC (Sun) by anton (guest, #25547) [Link]

And new bugs are introduced, and if they are for a non-default option like (now) data=ordered, they won't get noticed in time, and they won't get fixed for quite some time; at least that's what the non-default data=journal episode teaches. So what's higher: the risk of data loss from a well-known kernel, or from a new kernel in a non-default setting? Choosing the latter seems foolish to me.

Modifying fstab is not a big deal, why would I want to avoid it. The problem with doing it in the superblock is that I have to do it again when I transfer the system to another disk.

ext4 and data consistency

Posted May 23, 2010 11:50 UTC (Sun) by cortana (subscriber, #24596) [Link]

How can I check whether my distribution has changed the default value of the option in its kernels?

ext4 and data consistency

Posted May 23, 2010 13:29 UTC (Sun) by anton (guest, #25547) [Link]

One way is to mount such a file system with the default value (without overriding the default with tune2fs or in fstab), and the checking the actual options in /proc/mounts. That is what I do.

Another way would be to check CONFIG_EXT3_DEFAULTS_TO_ORDERED in the kernel config file.

ext4 and data consistency

Posted May 23, 2010 13:55 UTC (Sun) by nix (subscriber, #2304) [Link]

Well, OK, you're quite within your rights to stick with an old kernel: but I hope you encounter no other security bugs, or stability bugs, or new hardware, or *anything* else that might require a new kernel!