Re: Initdb --data-checksums by default - Mailing list pgsql-general

From John R Pierce
Subject Re: Initdb --data-checksums by default
Date
Msg-id 57176AAC.7080703@hogranch.com
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In response to Re: Initdb --data-checksums by default  (Alex Ignatov <a.ignatov@postgrespro.ru>)
List pgsql-general
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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