Re: RAID-1 mdadm software raid and kernel crashing on hdd failure

[Pasi Kärkkäinen <pasik@xxxxxx>]

On Fri, Mar 26, 2010 at 11:14:18AM -0700, Benjamin Franz wrote:
> Robert Heller wrote:
> >
> > I suspect that this is a simular case to what I did: I have a server
> > with 4 drives.  I have several (small) RAID1 partitions (/boot, /,
> > /usr, /var, etc.) with 4 mirrors and one large RAID5 with three
> > partitions and a hot spare (a LVM volumn group, containing /home and
> > some other partitions). I would guess that the admin with the "8-way
> > RAID1 for the OS" probably also has a 6 or 8 disk RAID5 or RAID6 for
> > the bulk of the disks
> Yup. 8 way RAID1 for the OS, 8 way RAID6 for the data. I was hoping when 
> I setup the 8-way RAID1 for the OS that I would get really good read 
> speeds since md is supposed to stripe reads from RAID1, but in practice 
> the RAID6 completely kills it for read performance (~61 MB/sec from the 
> RAID1 partition vs ~200 MB/sec from the RAID6 partition).
> 
> In a deeply ironic turn of events, one of the hard drives in that 
> machine died in a way that freaked the hardware controller driver out 
> and caused a kernel panic last week.
>

I've also seen CentOS 5.3 (or 5.4, not sure) crash when a single sata hdd failed.
The system was running mdadm RAID-1 mirror, so it shouldn't have been fatal event..

There was kernel oops on the console. too bad I didn't have time to capture it then.
System was running AHCI SATA on Intel ICH9 controller, with mdadm software raid.

So there's still need for hardware RAID controllers..

-- Pasi

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