[mythtv-users] Linux software raid question

[Graham Mitchell]

-----Original Message-----
From: mythtv-users-bounces at mythtv.org
[mailto:mythtv-users-bounces at mythtv.org] On Behalf Of John Drescher
Sent: Friday, June 06, 2008 6:12 PM
To: Discussion about mythtv
Subject: Re: [mythtv-users] Linux software raid question

<snip>


> I have done this most of the time even though I know that growing
> exists. I believe this a much safer approach if you do not have a
> backup.

I totally agree, which is why I have done it that way in the past. 


> However I do know that the linux raid code is very robust,
> during a grow test I rebooted the machine while it was growing the
> array and when the system came back up it continued where it left off.

Yeah, the code is very robust. There are only 2 real issues I've come across
trying to grow arrays (by adding extra drives). Firstly, it can get upset if
the server dies during the initial 'critical stage' backup that it makes.
Second way it gets upset, is when you're new drive had bad sectors on it. It
gets REALLY upset when both happen at the same time.

Having said all that, Neil Brown on the mdadm mailing lists is VERY helpful,
and managed to get me out of a couple of these tricky situations.

The one thing that I do now before adding any drive into an array is a
badblocks -svw, and if anything shows up, the drive gets RMAd. The downside,
is that it takes about 36 hours to do a badblocks on a 500GB SATA drive -
but it's still worth it.


G