[olug] Home file server - FreeNAS or Openfiler or ???

[Christopher Cashell]

On Tue, Mar 29, 2011 at 9:31 AM, Kevin <sharpestmarble at gmail.com> wrote:
> A hundred times over? I know LVM is awesome, but I don't know that I'd go to
> that extreme. I do appreciate the extra flexibility that it affords us, but
> I don't think it's the be-all-end-all. If someone tries to give you
> something like that, them either a fanboi or they're trying to sell it
> something.

I'm not saying LVM is perfect (it's not), or that it does everything
(it doesn't).  But, when compared to straight raw partitions,
especially with recent LVM/kernel releases, I think the features do
outweigh the (negligible) faults a hundred times over.  There's just
not much in the way of faults for anyone with a good understanding of
LVM, and many of the features are incredibly useful.

> That said, given the situation here, is go the LVM route. It will let you
> dynamically expand or reduce a filesystem.

Expand and reduce filesystems, delayed allocation, take snapshots for
backups (now with merge support!), have consistent and reliable
(logical) device naming, pooling multiple disks into a single storage
pool, disk mirroring, etc.

A lot of people use LVM primarily when adding new physical disks.  And
it works great there.  But, one of the most useful things I've found
with LVM, and one of the reasons I use it for essentially every linux
box, is that you don't need to have a perfect understanding of what
your future needs will be for a system.

This is particularly useful when you've got got a lot of machines to
deal with, because you can install a standard base layout that will
work 95% of the time, but still manipulate it later to meet specific
needs.  If I have a 100GB disk, I might only allocate 50GB of it to
the initial system partitions, reserving the other 50GB in the LVM
Volume Group.  Then, six months down the road, when I discover I need
more disk space in /var, or find that a third party application I'm
using needs an additional 20GB in /opt, I can easily pull from that
reserve space and grow any partition I want.

The system disk(s) never get fully allocated at build time on boxes I work with.

-- 
Christopher