Re: [PERFORM] Arguments Pro/Contra Software Raid - Mailing list pgsql-general

From Markus Schaber
Subject Re: [PERFORM] Arguments Pro/Contra Software Raid
Date
Msg-id 4461F0A3.60102@logix-tt.com
Whole thread Raw
In response to Re: [PERFORM] Arguments Pro/Contra Software Raid  (Scott Lamb <slamb@slamb.org>)
Responses Re: [PERFORM] Arguments Pro/Contra Software Raid  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-general
Hi, Scott & all,

Scott Lamb wrote:

> I don't know the answer to this question, but have you seen this tool?
>
>     http://brad.livejournal.com/2116715.html

We had a simpler tool inhouse, which wrote a file byte-for-byte, and
called fsync() after every byte.

If the number of fsyncs/min is higher than your rotations per minute
value of your disks, they must be lying.

It does not find as much liers as the script above, but it is less
intrusive (can be ran on every low-io machine without crashing it), and
it found some liers in-house (some notebook disks, one external
USB/FireWire to IDE case, and an older linux cryptoloop implementations,
IIRC).

If you're interested, I can dig for the C source...

HTH,
Markus




--
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf.     | Software Development GIS

Fight against software patents in EU! www.ffii.org www.nosoftwarepatents.org

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