Re: Initdb --data-checksums by default

From: John R Pierce <pierce(at)hogranch(dot)com>
To: "pgsql-general(at)postgresql(dot)org" <pgsql-general(at)postgresql(dot)org>
Subject: Re: Initdb --data-checksums by default
Date: 2016-04-20 11:40:28
Message-ID: 57176AAC.7080703@hogranch.com
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On 4/20/2016 1:00 AM, Alex Ignatov wrote:
> Uncorrectable read error rate ~ 10^-15- 10^-14. This error stays
> undetected and uncorrectable.

what are your units here? disk IO is done by blocks, and the CRCs and
trellis codes used by the disk drives for error detection and correction
are applied on a whole block basis.

so is that one undetected error per 10^-14 blocks read, or what?

and what about file systems like ZFS that already do their own CRC ?

--
john r pierce, recycling bits in santa cruz

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