2010-10-17 00:29:51

by Daniel Taylor

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Subject: ext over RAID-[56]?

One of the program managers here asked me a question that I couldn't answer:

with ext[34] over a RAID-[56] volume, what protection against data
corruption
and loss of existing data does the file system provide for the case of an
incomplete update of the RAID "stripe"?

I know that anyone with any usable brain cells has their data server on a
nice
UPS, but not all customers are so equipped, and he's concerned about
corruption
during a power failure (loss of unwritten data is OK).

I can't see any configuration options that would help but I could easily be
missing something. Any ideas?

Thanks,

Dan Taylor
Sr. Staff Engineer
WD Branded Products


2010-10-17 10:38:54

by Amir G.

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Subject: Re: ext over RAID-[56]?

On Sun, Oct 17, 2010 at 2:16 AM, Daniel Taylor <[email protected]> wrote:
> One of the program managers here asked me a question that I couldn't answer:
>
> with ext[34] over a RAID-[56] volume, what protection against data
> corruption
> and loss of existing data does the file system provide for the case of an
> incomplete update of the RAID "stripe"?
>
> I know that anyone with any usable brain cells has their data server on a
> nice
> UPS, but not all customers are so equipped, and he's concerned about
> corruption
> during a power failure (loss of unwritten data is OK).
>
> I can't see any configuration options that would help but I could easily be
> missing something. ?Any ideas?
>

I don't think you are missing something. check out this article:
http://lwn.net/Articles/349970/