Xserve G5 with megaraid can not boot after sudden powerloss

[Dan Shoop]

On Aug 14, 2007, at 9:54 AM, Christoph Ewering wrote:

> Hello!
>
> I just got a call from a customer that they accidently unplugged a  
> running server. And after they restarted the server it will show a  
> grey screen and a blinking sign. The server is a Xserve G5 with a  
> megaraid card running a RAID-5 array that contains one journaled  
> volume with the operating system.
>
> Now I am a little bit confused - why the server can not boot any more?
> This should not happen, right?
> Looks like the filesystem was damaged, right? But how? The megaraid  
> has a backup-battery (if I remember right) and the filesystem on  
> the volume is journaled. So I was thinking that a sudden powerloss  
> could not damage the filesystem in such a way that the system i  
> unbootable.
>
> The server has no heavy load when it was unplugged - to be more  
> clear - this special server is idling 99.9% of the day, but it  
> contains one service that is needed from time to time.
>
> I appreciate every hint how to repair this megaraid problem.
>
> Should I start from DVD and repair with DiskUtility? Something I  
> can check with megaraid? I think I can boot the server with a MacOS  
> X 10.4.7 DVD.

It's well known that the MegaRAID card (and many others) may not  
properly flush cache to disk during shutdown (especially during  
unorderly shutdown). It's one of the reasons they're no longer sold.


-dhan

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Dan Shoop <shoop at iwiring.net>
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