[rhelv6-beta-list] Volume management with btrfs (and LVM) -- WAS: My first experiences with RHEL6 beta

[Bryan J. Smith]

o  "Real-world" discussion portion ...

Chris Adams <cmadams at hiwaay.net> wrote:
> I understand that btrfs is going to have this type of integration
> between the filesystem and logical storage management ...

This is the Red Hat Enterprise Linux release 6 Beta list, and it
includes btrfs as a "Tech Preview":  
http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6-Beta/html/Beta_Release_Notes/filesystems.html#id479056  

As much as I've been a horrendous example of someone entertaining
meta-discussions now as anyone else, I would like to help people
utilize RHEL 6.  Bugzillas are always appreciated.  ;)

btrfs is a facility in RHEL 6 that has a "Tech Preview" now.


o  "Meta-discussion" portion ...

Chris Adams <cmadams at hiwaay.net> wrote:
> There are a couple of issues that make LVM less-useful than
> it could be:

Okay, that now add a 4th, and separate meta-discussion context ...

4.  Wish lists (that "the older methods" couldn't even dream of)

I have added #4 because it's no longer comparing to the, and I'll
use the prior term, "the older methods."  #1-3 were in comparison to
"the older methods."  And in this case, volume management is the
_only_ way we're going to get there.

> - Lack of advanced tools: Bryan mentioned moving PEs
> around, but right now that's a PITA.  If you want to "defrag"
> your LVs,

Defragmentation is a function of the filesystem and, just like
resizing the filesystem, have nothing to do with LVM or volume
management.  This is the same on _all_ OSes.  ;)

> kernel folks may like block devices and filesystems to be separate,
> but admins and users just want easily-managed disk space.

You mean like NetApp's Data On-Tap OS and WAFL filesystem-integrated
volume management?

There have been many approaches as such, including around SGI's XFS
filesystem and Sun's ZFS.  They even had integrated service facilities.

And in virtually all cases, to get all of their features, you had
specific hardware requirements and assumptions.  They will never be
generic enough.

But btrfs looks promising.

(end of meta-discussion, I'll leave it to others)