LVM negates benefits of jounaling filesystems? [was RFE: autofsck]

[Andrew Haley]

max bianco wrote:
> On Tue, Jun 10, 2008 at 9:46 AM, Chuck Anderson <cra at wpi.edu> wrote:
>> On Tue, Jun 10, 2008 at 08:36:31AM -0500, Eric Sandeen wrote:
>>> journaling filesystem you really shouldn't have any filesystem metadata
>>> integrity problems on power loss; that is, if you have barriers on
>>> (which ext3 doesn't by default) and if your storage can pass barriers
>>> (which lvm doesn't), or if you have drive write cache disabled (which
>>> hurts performance pretty badly).
>> I wasn't aware that LVM destroyed the kind of guarantees about
>> filesystem metadata being written out to disk that jounaling
>> filesystems rely on?  If so, should we perhaps rethink the decision to
>> use LVM by default on Fedora installs?
>>
> 
> What was the reason for using LVM in the first place. My most recent
> install I was really tempted to not go with the defaults but because I
> really don't know much about filesystems, I figured the best thing in
> that case was stick to the defaults. Now I am reconsidering
> again...could someone explain the comparative advantages/disadvantages
> ? Before i do something stupid .

LVM has a lot of advantages with regard to flexibility: you can add a
disk to a filesystem, for example.  It has a lot of nice features.

Andrew.