[aklug] Re: What should I consider before doing an install?

On Thu, 30 Jun 2011, bryanm@acsalaska.net wrote:

> Why is that? I understand that the benefit of LVM is being able to
> move and resize filesystems. But is there something that makes the
> initial setup easier with LVM than without it? And what is the greater
> protection you allude to?

The greater protection comes from mounted filesystems with greater
restrictions. Noexec, nosuid, nodev, etc. Before the advent of LVM,
though, having a large number of filesystems was difficult to manage because
it was nearly impossible to anticipate how much storage you needed to
preallocate to each filesystem. So, you either eliminated many of the the
extra filesystems or built a system with so much storage that you could
oversize everything.

The LVM advantage lets us implement the larger # of secured filesystems
without being psychic. Add space to live filesystems as needed from your
global pool of unallocated storage in the VG.

> Also, while I understand the purpose of an initrd, it's always seemed
> like more trouble than it was worth. It's an awful lot to go through
> just to get the darn thing booted (and more steps to forget during an
> update). If you just make sure your kernel has what it needs to run
> the system, most of the reason for the initrd goes away, right?
> (Except for LVM, at least.)

For most things, yes, you don't need an initrd. For that matter, you don't
need udev, either. If you're willing to have a static partition as your
root filesystem you can avoid it and still use LVM for all the other
partitions. But, if you want consistency and the same feature set across
all of your mounted filesystems (willfully ignoring /boot, of course), then
you'll want initrd.

Personally, storage management is extremely important to me, so I want
everything, swap, rootfs, etc., in LVM, so initrd is the only sane way to
go. And for those of you running stock distro kernels with the kitchen sink
driver thrown in as modules, it's pretty much a necessity as well.

> I prefer to avoid an initrd, though I may end up using it -- for the
> technical benefits and/or just learning how it works.

Well, you hit upon an excellent argument. 95% of what everyone here wants
to do makes an initrd more or less irrelevant. That said, just about
everyone (including me) uses them, so it'll be hard to avoid if you're
running off-the-shelf distros. So, it behooves you to learn it if you can.
And, should you eventually become interested in that 5% that requires it,
you'll already be comfortable enough with it to manage it.

         --Arthur Corliss
           Live Free or Die
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Received on Thu Jun 30 11:18:10 2011