xfs
[Top] [All Lists]

Re: How do I tell if my partition is aligned for a 64k/RAID-6?

To: Justin Piszcz <jpiszcz@xxxxxxxxxxxxxxx>
Subject: Re: How do I tell if my partition is aligned for a 64k/RAID-6?
From: "Josef 'Jeff' Sipek" <jeffpc@xxxxxxxxxxxxxx>
Date: Sat, 27 Dec 2008 08:58:22 -0500
Cc: Michal Soltys <soltys@xxxxxxxx>, linux-raid@xxxxxxxxxxxxxxx, xfs@xxxxxxxxxxx
In-reply-to: <alpine.DEB.1.10.0812270850490.15403@xxxxxxxxxxxxxxxx>
References: <alpine.DEB.1.10.0812250821360.31386@xxxxxxxxxxxxxxxx> <495410F4.5010508@xxxxxxxx> <alpine.DEB.1.10.0812251846270.32331@xxxxxxxxxxxxxxxx> <20081227133824.GH6284@xxxxxxxxxxxxxx> <alpine.DEB.1.10.0812270850490.15403@xxxxxxxxxxxxxxxx>
User-agent: Mutt/1.5.18 (2008-05-17)
On Sat, Dec 27, 2008 at 08:53:21AM -0500, Justin Piszcz wrote:
> Why bother partitioning?  I also run a Linux SW RAID1 on the host, as you 
> know the drive letters can change when working on a server.
>
> Example: Before I created the array (RAID-6), my disks were /dev/sda,  
> /dev/sdb and /dev/sdc (spare), the RAID-6 was /dev/sdd.  After reboot,  
> /dev/sdd became /dev/sda and /dev/sd[a-c] became /dev/sd[b-d].
>
> In lilo.conf I had:
> raid-extra-boot="/dev/sda,/dev/sdb"
>
> If I ran LILO and forgot to fix the lilo.conf to reflect the new drive  
> mappings:
> raid-extra-boot="/dev/sdb,/dev/sdc"
>
> I could be at risk of ruining the partition?

Hrm...interesting point. LILO could mess up the superblock in sector 0.

> I try to avoid such situations when possible, to be safe.

:)

I don't know how LILO would handle it, but I would try to use
/dev/disk/by-*/* instead of the rather unstable /dev/sd* names.

Just my 0.02 cents.

Jeff.

-- 
Keyboard not found!
Press F1 to enter Setup

<Prev in Thread] Current Thread [Next in Thread>