Re: Reliability recommendations - Mailing list pgsql-performance

From Craig A. James
Subject Re: Reliability recommendations
Date
Msg-id 43FF92EB.7060704@modgraph-usa.com
Whole thread Raw
In response to Re: Reliability recommendations  ("Joshua D. Drake" <jd@commandprompt.com>)
Responses Re: Reliability recommendations  (Scott Marlowe <smarlowe@g2switchworks.com>)
List pgsql-performance
Joshua D. Drake wrote:
>> I find this strains credibility, that this major manufacturer of PC's
>> would do something deceptive that hurts performance, when it would be
>> easily detected and widely reported.  Can anyone cite a specific
>> instances where this has happened?  Such as, "I bought Dell model XYZ,
>> which was advertised to have these parts and these specs, but in fact
>> had these other parts and here are the actual specs."
>
> I can :)
>
> Feb 20 07:33:52 master kernel: [4294682.803000]   Vendor: MegaRAID
> Model: LD 0 RAID1   51G  Rev: 196T
> --- snip ---
> This machine... if you run it in raid 5 will only get 7-9 megabytes a
> second READ! performance. That is with 6 SCSI drives.
> If you run it in RAID 10 you get a more reasonable 50-55 megabytes per
> second.

But you don't say how this machine was advertised.  Are there components in that list that were not as advertised?  Was
themachine advertised as capable of RAID 5?  Were performance figures published for RAID 5? 

If Dell advertised that the machine could do what you asked, then you're right -- they screwed you.  But if it was
designedfor and advertised to a different market, then I've made my point: People are blaming Dell for something that's
nottheir fault. 

Craig

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