On Dec 10, 2009, at 7:52 PM, Mark Caudill markca@codelulz.com wrote:
Christopher Chan wrote:
Morten Torstensen wrote:
On 08.12.2009 13:34, Chan Chung Hang Christopher wrote:
Speaking for me (on Linux systems) on top of LVM on top of md. On IRIX as it was intended.
That is a disaster combination for XFS even now. You mentioned some pretty hefty hardware in your other post...
If XFS doesn't play well with LVM, how can it even be an option? I couldn't live without LVM...
I meant it in the sense of data guarantee. XFS has a major history of losing data unless used with hardware raid cards that have a bbu cache. That changed when XFS got barrier support.
However, anything on LVM be it ext3, ext4 or XFS that has barrier support will not be able to use barriers because device-mapper does not support barriers and therefore, if you use LVM, it better be on a hardware raid array where the card has bbu cache.
Wait, just to be clear, are you saying that all use of LVM is a bad idea unless on hardware RAID? That's bad it if it's true since it seems to me that most modern distros like to use LVM by default. Am I missing something?
If you use a leading edge distro then they will most likely be using a LVM version with barrier support as it was implemented as of 2.6.29-2.6.30+.
It should be backported by the next release of CentOS hopefully.
-Ross