[linux-lvm] LVM onFly features

[Graham Wood]

On Sat, Dec 10, 2005 at 01:14:54PM -0700, Michael Loftis wrote:
> Not a problem, a lot of people don't see the delineation right off. 
> Filesystems like VXVFS (Veritas) in their commercial implementations are 
> really LVM+Filesystem in one.  Not sure what the linux port is looking like 
> these days though.
Actually veritas have multiple products, and the FS is separate to
the LVM (E.g. there is file system and volume manager - which are
different products but can be purchased together as part of the
'foundation suite').

> ReiserFS has hot expansion capabilities, but no (yet?) hot shrinking 
> capabilities.  One of the reasons it has these features and ext2/3 does not 
> is because ext2/3 are very old filesystems designed on a different 
> mentality of a static filesystem.  On-line expansion of ext2 based 
> filesystems is an extremely complicated venture, it might honestly even be 
> impossible.
Um.  I've got a couple of RHEL4 boxes at work, and redhat ship
'ext2online' with the platform - that has grown my ext3 filesystems
multiple times.  One of the volumes I've got has been grown 5 times
since the machine was last rebooted - and seems to be fine.


(apologies for the offtopic discussion, but want to make sure that
people leave with accurate answers *grin*)