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Art,
Your comments on this?

Cheers,
Asheesh.

> -----Original Message-----
> From: Bob Bankay [mailto:bobb@ssl.berkeley.edu]
> Sent: Wednesday, August 27, 2003 4:48 AM
> To: informix-list@iiug.org
> Subject: Re: WHY index can corrupted???
>=20
>=20
> miyaki wrote:
> > Hi all,
> >=20
> > OS : Sun Solaris 2.7
> > IDS : 7.31.UD5
> <snip>
> >=20
> > Anybody knows the reason that may cause the index
> > corruption???
> >=20
> > Appreciate for the comments.
> >=20
> > TIA,
> > MIyaki
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> We use similar hardware and OS in a very high volume db=20
> application. We=20
> used caching RAID
> disk controllers that would corrupt data long after it had given IO=20
> complete to Solaris and Informix. So neither the OS nor the=20
> db engine=20
> had anyway to handle a hardware corruption at a later time. =20
> At the time=20
> we were using controllers with 128MB cache in RAID 1+0=20
> config. Somehow,=20
> the hardware would write corrupt data with correct parity, and the=20
> mirror manager would not know which image was correct. Hence index=20
> failures.
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> Normally we would find out about corruption when doing backups. The=20
> only way to cure the problem was to get rid of the caching=20
> controllers.=20
> We now use RAID 5 which is slower but can self heal from intermittent=20
> disk failures. Thus, we have less performance but no more corruption=20
> for the past 2 years.
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> Just one more experience.
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> Bob B
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>=20

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