[mythtv-users] An LVM'd drive died! What do I do...

Brandon Beattie brandon+myth at linuxis.us
Thu Oct 27 09:59:29 EDT 2005

On Wed, Oct 26, 2005 at 11:26:47PM -0500, Korey Fort wrote:
> As far as I know if you lose a disk in an LVM dies you're SOL.  If you 

Untrue, you only lose everything if it is the first drive (Unless
something really odd happens).  I've tested just pulling a drive and
shrinking the lvm and it did just fine, but I did lose data that was on
the pulled drive.

A few months ago I wrote several e-mails to the list explaining how to
build LVM in a way that you have a better chance of recovering if you
have problems.  Raid to several of us who run TB+ LVM's for a myth box
is a dumb idea.  I've been through a number of failed drives and my
current setup is very functional in getting around quite a few types of
failing drives (Note failing, not failed) with little or no data loss.

In short, use reiserFS (Not reiser4) as reiserFS is the best choice of
FS that supports shrinking (Which you'll want if you don't have an extra
drive atleast as large as the largest disk, sitting around.)  Don't do
stripping, there's no reason too for Myth unless you have 15 HD tuners
and are streaming to 15+ frontends.  Tarball your root fs (Mine is 4GB)
every month or so and put it on another system, just incase the main
disk goes out (You still have a chance to recover files on other drives
if you do this often, plus you can just untar your root fs using a
rescue CD on a new drive)  

I've used raid 0, 1 and 5 at points in the past with my mythboxes, and it
was all a waste of time in my opinion.  The only safe way to note lose
data is store it offline.  I've had power supplies go back on software
raid systems for work and fry 2-8 drives at once -- Raid 5 is no match
for fried hardware that occurs at the same time.

In my opinion, buying better hardware is much cheaper than spending time
tring to handle when it happens, and when it happens you restore from
offline copies.  I've gone through 5 Maxtor 200gb drives in the last 3
years, I used to think they were good but they're now junk.  The only
brand I trust is Seagate now.  Their 5 yr warranty pays for itself if
you have several drives that fail all the time, most all HD warranties
are 1 yr, most drives I've had last 1.75 years average.

My setup is 4x200GB 1x250GB 1x300GB, 

Hopefully in the next few months myth will support storing to multiple
directories, which would remove the need for LVM or having to worry
about losing anything but what was on that drive.


More information about the mythtv-users mailing list