[olug] Mirroring a boot drive

[Justin Reiners]

Periodically dd your drive and compress it to another location, then you
can just dd it to a new drive the same or larger in size.

Honestly, I'm not sure the best way to do it from a live system, it's been
a long time since I have used software raid, everything I have has a raid
card onboard.

I remember horror stories of software raid screwing up when we used it, not
being able to replace drives, no documentation, and onsite helping hands
tech confusion.

Someone here might know.

If I had to do it, I'd buy a pci express raid card, do a full backup, buy a
couple new SSDs and dd the info back on to the new raid, but I am almost
positive someone here might have a more elegant solution.



On Wed, Sep 26, 2018 at 10:40 PM Ben Hollingsworth <obiwan at jedi.com> wrote:

> I've got a Ubuntu system (currently 16.04, but soon 18.04) with a
> single, 5.5-yr-old SSD boot/root drive and a handful of other disks in a
> RAID5 data array.  I'd like to add a second boot drive to create a RAID1
> mirror, since the current boot drive won't last forever.
>
> There are plenty of instructions available for installing a fresh Ubuntu
> server install on a RAID1 partition.  However, I need to keep & upgrade
> my existing install, since it's heavily customized.  I can't find any
> instructions specifically for this scenario.  Have any of you ever done
> this?
>
> The idea I've had is to install the new disk and unplug the existing
> boot disk.  Install a fresh 18.04 server release using the new disk and
> some spare space from another old disk as the mirrored pair. Once that's
> running, copy the old boot drive's data on top of the new boot drive
> (this is the part I'm not sure will work well).  Once the new
> drive/mirror is set up with my old OS, remove the old spare drive from
> the mirror and replace it with the old boot drive.  Yes, I have multiple
> backups.
>
> Does that sound plausible?  Is there a better way?
>
> I suppose the alternative is to just keep running off a single drive,
> and replace the old one as soon as it throws the first SMART error.
> That makes me nervous, though.
>
> --
> *Ben "Obi-Wan" Hollingsworth* obiwan at jedi.com <mailto:obiwan at jedi.com>
> www.Jedi.com <http://www.jedi.com>
> The stuff of earth competes for the allegiance I owe only to the
> Giver of all good things, so if I stand, let me stand on the
> promise that You will pull me through. /-- Rich Mullins/
>
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