On Tue, Apr 14, 2009 at 06:33:50PM +0200, Anton Ertl wrote:Andi Kleen wrote:"Anton Ertl" <anton@xxxxxxxxxxxxxxxxxxxxxxxxxx> writes:Thank you. I added the following to the README:/dev/md2 /home ext3 defaults,barrier=1 1 2Just make sure /dev/md2 is a RAID1, MD RAID0/5/10 don't support barriers.
|Note that, as of this writing (2009-04), not all Linux devices support
|barriers, in particular md devices only support them in RAID 1 mode;
|the kernel will reportedly warn about the lack of barriers if you try
|to use ext3 with barriers on a device that does not support barriers
|(look in, e.g., dmesg).
A full listing of what devices do and don't support barriers would
be likely very long. You would actually need to list down to hard disks.
A common problem is barriers over LVM. Since 2.6.29 they work
with a single device (and if the underlying device supports it) with dm linear, but not in any other LVM setup.