Write barriers in 11.4

<6> 0.278631] xen-vbd: registered block device major 202
<6> 0.278655] blkfront: xvdd: barriers enabled
<6> 0.279218] xvdd: unknown partition table
<6> 0.280697] blkfront: xvda: barriers disabled
<6> 0.291301] xvda: xvda1 xvda2 xvda3

Anyone know why write barriers are disabled for /dev/xvda according to my boot logs? What would I be looking for to solve this?
I know that barriers are enabled in the host OS.

Never mind. My host OS is Citrix’s XenServer 5.6 and it’s kernel is 2.6.27.42. While the host gets to use barriers, the guest’s reside on an LVM and barrier support isn’t available until 2.6.33.
That really stinks for our intended use, which is a database that uses careful writes.