[CentOS] Centos/Linux Disk Caching, might be OT in some ways

[Noob Centos Admin]

Hi,

On 1/27/10, Ross Walker <rswwalker at gmail.com> wrote:
>
> But if your doing mysql on top of LVM your basically doing the same,
> cause LVM (other then current kernels) doesn't support barriers.
>
> Still if you have a battery backed write-caching controller that
> negates the fsync risk, LVM or not, mysql or postgresql.

This is a bit of a surpise. Am I understanding correctly that running
postgresql or mysql on top of LVM negates any data reliability
measures the DBMS might have in the event of an unexpected shutdown?

I have several servers configured to run LVM on top of MD1 for the
convenience of being able to add more space to a volume in the future.
I didn't realize this was a reliability risk. :(