On Jan 21, 2010, at 4:04 PM, Tom Georgoulias <tomg at mcclatchyinteractive.com > wrote: > Ran into a confusing situation today. When I mount an xfs > filesystem on > a server running centos 5.4 x86_64 with kernel 2.6.18-164.9.1.el5, the > barrier/nobarrier mount option as displayed in /proc/mounts is always > set to "nobarrier" > > Here's an example: > [root at host ~]# mount -o nobarrier /dev/vg1/homexfs /mnt > [root at host ~]# grep xfs /proc/mounts > /dev/vg1/homexfs /mnt xfs rw,attr2,nobarrier,noquota 0 0 > [root at host ~]# mount | grep xfs > /dev/mapper/vg1-homexfs on /mnt type xfs (rw,nobarrier) > > [root at host ~]# mount -o barrier /dev/vg1/homexfs /mnt > [root at host ~]# grep xfs /proc/mounts > /dev/vg1/homexfs /mnt xfs rw,attr2,nobarrier,noquota 0 0 > [root at host ~]# mount | grep xfs > /dev/mapper/vg1-homexfs on /mnt type xfs (rw,barrier) > > Can anyone else confirm this behavior? LVM doesn't support barriers. -Ross