LVM snapshot

[Bill Rugolsky Jr.]

On Tue, Aug 17, 2004 at 08:33:17AM -0500, Chris Adams wrote:
> Once upon a time, Paul Jakma <paul at dishone.st> said:
> > 1. A good reason to not put root on LVM - your rootfs is your primary 
> > rescue partition.. Why would you need LVM for root fs anyway?

One can readily put a rescue image in /boot and add an appropriate Grub
entry.  Doing so enables maintenance tasks that require unmounting the
filesystem, e.g., shrinking it, or rolling back to a snapshot, which
are ordinarily difficult with system volumes.

> Why would you need LVM for any FS?
> 
> - Ability to easily resize partitions to meet changing needs.  This
>   applies to root as well (ever had to blow everything away because root
>   needed to be larger for an upgrade?).
> 
> - Ability to easily migrate to new storage.  I haven't used this with
>   Linux LVM, but I have migrated Tru64 AdvFS filesystems from one set of
>   drives to another without having to shut down; combined with on-line
>   filesystem resizing, you never need to shut down for storage
>   maintenance again.

And, of course,

  - Snapshot the filesystem for consistent backups, and background fsck.

Regards,

   Bill Rugolsky