[rhelv6-beta-list] My first experiences with RHEL6 beta

[Jon Masters]

On Sat, 2010-06-12 at 13:40 -0400, Nico Kadel-Garcia wrote:

> While LVM is useful for re-allocating disk space for
> alternative partition layouts, and its snapshot capability is very
> useful in some environments, and it can handle this reasonably
> gracefully, it does absolutely nothing for resizing the filesystems.

Filesystems can generally be resized (not always live) and then the
volume that contains them can be resized accordingly. Using LVM provides
this option, whereas using a raw disk partition or device does not.

> LVM is also a bad, bad, bad idea for virtualized environments

I use it extensively for my virtualized guests, both on the host and on
the guest instance. It works fine for the situations in which I use it.
Poking at the innards of the guest isn't a huge problem, though if they
happen to use exactly the same names it is a bit more of a pain. But
then, there is also http://www.libguestfs.org/ as an option.

> >> When I do want swap, I usually want a swap file
> >
> > I am not aware of many distributions that support this mode of
> > operation, and I can't remember the last time I was asked about it (vs.
> > some unusual nbd-type-swap) but I do think there's some merit in having
> > file based swap in the general longer term if we get good low-memory
> > notification and reservation support upstream so we can have the system
> > dynamically adjust the swap size. But again, I am not aware of anyone
> > really asking for that, I'm just interested for academic reasons.

> For virtualized guest images, it's common to use a distinct swap disk
> image so that the swap can go on separate server disk, space that is
> not backed up or used for virtual guest snapshots.

That's reasonable. But it's still not a reason to use a "swap file".

Jon.