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Today's Topics:
1. Re: Postgres optimised h/w (Nigel Sollars)
2. Re: Postgres optimised h/w (Martin Moore)
----------------------------------------------------------------------
Message: 1
Date: Fri, 16 Dec 2016 20:14:09 -0500
From: Nigel Sollars <nsollars@gmail.com>
To: Amias Channer <me@amias.net>, Bristol and Bath Linux User Group
<bristol@mailman.lug.org.uk>
Cc: Martin Moore <martinm@it-helps.co.uk>, Martin
<inkubus@interalpha.co.uk>
Subject: Re: [bristol] Postgres optimised h/w
Message-ID:
<CAG6aBkW7kJ_XWo2HLHswp7h7T+kSvzaw-0ZnK3XrhqiPfRBFQg@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Isnt raid normally for Corps anyhow?... I mean really unless your a data
hungry monster whats the point?..
The last person I knew that was using Raid was using a hardware card cause
he was streaming anything and everything using it .. and had quite a nifty
size to boot, of course there is always the 'Cause I can' clause ...
But really for the average person Raid is just not needed ...
On Fri, Dec 16, 2016 at 12:25 PM, Amias Channer via Bristol <
bristol@mailman.lug.org.uk> wrote:
> Hello Luggers,
>
> I would definitely agree that software raid is as good as hardware
> raid unless you are a mega corporation, in which case just do it all
> in live RAM anyway. The complexity and proprietary formats make them
> dangerous. Server bioses don't need any more reasons to boot up slowly
> which is usually the case with hardware raid.
>
> Server storage is IMHO really about concurrent access and RAID helped
> improve that on hard disks but its pretty much pointless on SSD/NVMe
> solutions where nothing is spinning and an individual drive can
> saturate the controller. Mirroring in this context is useful but
> really only to slower storage like HDD.
>
> +1 on the ECC ram , it should be standard on anything more than 16GB.
>
> Cheers
> Amias
>
> On 16 December 2016 at 17:05, Martin Moore via Bristol
> <bristol@mailman.lug.org.uk> wrote:
> > I have to say that in my decades of experience, adding h/w such as raid
> controllers, multiple psu sharing boards etc. usually results in the
> resilience bit failing! I've lost systems due to failed raid controllers
> and power sharing boards more than failed drives and PSUs!
> >
> > I've also heard that h/w RAID controllers use their own format which
> renders them useless without the controller.
> >
> >
> >
> >
> > On 16/12/2016, 16:36, "Bristol on behalf of Martin via Bristol" <
> bristol-bounces@mailman.lug.org.uk on behalf of bristol@mailman.lug.org.uk>
> wrote:
> >
> > On Fri, 2016-12-16 at 16:26 +0000, Steve King via Bristol wrote:
> > > >
> > > > I would also recommend a hardware RAID controller for a
> database: MD
> > > > RAID is great but far less flexible, and the more processing and
> IO you
> > > > can farm off to dedicated hardware the faster your database
> server will
> > > > go.
> > > >
> > >
> > > In what way is MDRAID less flexible than hardware raid?
> > > I have never found hardware raid offers more performance or more
> > > flexibility, plus you are at the mercy of the hardware vendor if
> you hit a
> > > problem.
> > ^^^^^^^^^^^^^ THISTHISTHIS! What he said!
> >
> > I have recovered RAID systems (personally and advised people in doing
> > so) that were theoretically broken past the point of repair. This
> > required reading the kernel source but we got all of the data back.
> I
> > have seen systems built on hardware RAID with a fraction of the
> problems
> > leading to complete data loss because the vendor wouldn't even bother
> > answering questions unless you were bringing them millions in
> revenue.
> >
> > Unless you REALLY REALLY need the extra performance (and are sure
> that
> > you get it) I'd suggest software RAID.
> >
> > That said, don't most of the big database servers have a "work
> directly
> > from the partitions and balance data as you see fit" mode? Because
> for
> > them filesystems are just overhead.
> >
> > Cheers,
> > - Martin
> >
> >
> >
> > _______________________________________________
> > Bristol mailing list
> > Bristol@mailman.lug.org.uk
> > https://mailman.lug.org.uk/mailman/listinfo/bristol
> >
> >
> >
> > _______________________________________________
> > Bristol mailing list
> > Bristol@mailman.lug.org.uk
> > https://mailman.lug.org.uk/mailman/listinfo/bristol
>
> _______________________________________________
> Bristol mailing list
> Bristol@mailman.lug.org.uk
> https://mailman.lug.org.uk/mailman/listinfo/bristol
>
--
"Science is a differential equation. Religion is a boundary condition."
Alan Turing
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Message: 2
Date: Sat, 17 Dec 2016 09:42:14 +0000
From: Martin Moore <martinm@it-helps.co.uk>
To: Bristol and Bath Linux User Group <bristol@mailman.lug.org.uk>
Subject: Re: [bristol] Postgres optimised h/w
Message-ID: <841FE578-124E-41F5-B2D7-481552314A45@it-helps.co.uk>
Content-Type: text/plain; charset="utf-8"
It's for anyone who needs it!
I use RAID1 (mirroring) and have lost a few partitions over the years and this has allowed the systems to keep running without issue.
And this is for a commercial system – and I don't remember asking 'is ensuring your data is safe a bad idea' ;)
Martin.
From: Nigel Sollars <nsollars@gmail.com>
Date: Saturday, 17 December 2016 at 01:14
To: Amias Channer <me@amias.net>, Bristol and Bath Linux User Group <bristol@mailman.lug.org.uk>
Cc: Martin Moore <martinm@it-helps.co.uk>, Martin <inkubus@interalpha.co.uk>
Subject: Re: [bristol] Postgres optimised h/w
Isnt raid normally for Corps anyhow?... I mean really unless your a data hungry monster whats the point?..
The last person I knew that was using Raid was using a hardware card cause he was streaming anything and everything using it .. and had quite a nifty size to boot, of course there is always the 'Cause I can' clause ...
But really for the average person Raid is just not needed ...
On Fri, Dec 16, 2016 at 12:25 PM, Amias Channer via Bristol <bristol@mailman.lug.org.uk> wrote:
Hello Luggers,
I would definitely agree that software raid is as good as hardware
raid unless you are a mega corporation, in which case just do it all
in live RAM anyway. The complexity and proprietary formats make them
dangerous. Server bioses don't need any more reasons to boot up slowly
which is usually the case with hardware raid.
Server storage is IMHO really about concurrent access and RAID helped
improve that on hard disks but its pretty much pointless on SSD/NVMe
solutions where nothing is spinning and an individual drive can
saturate the controller. Mirroring in this context is useful but
really only to slower storage like HDD.
+1 on the ECC ram , it should be standard on anything more than 16GB.
Cheers
Amias
On 16 December 2016 at 17:05, Martin Moore via Bristol
<bristol@mailman.lug.org.uk> wrote:
> I have to say that in my decades of experience, adding h/w such as raid controllers, multiple psu sharing boards etc. usually results in the resilience bit failing! I've lost systems due to failed raid controllers and power sharing boards more than failed drives and PSUs!
>
> I've also heard that h/w RAID controllers use their own format which renders them useless without the controller.
>
>
>
>
> On 16/12/2016, 16:36, "Bristol on behalf of Martin via Bristol" <bristol-bounces@mailman.lug.org.uk on behalf of bristol@mailman.lug.org.uk> wrote:
>
> On Fri, 2016-12-16 at 16:26 +0000, Steve King via Bristol wrote:
> > >
> > > I would also recommend a hardware RAID controller for a database: MD
> > > RAID is great but far less flexible, and the more processing and IO you
> > > can farm off to dedicated hardware the faster your database server will
> > > go.
> > >
> >
> > In what way is MDRAID less flexible than hardware raid?
> > I have never found hardware raid offers more performance or more
> > flexibility, plus you are at the mercy of the hardware vendor if you hit a
> > problem.
> ^^^^^^^^^^^^^ THISTHISTHIS! What he said!
>
> I have recovered RAID systems (personally and advised people in doing
> so) that were theoretically broken past the point of repair. This
> required reading the kernel source but we got all of the data back. I
> have seen systems built on hardware RAID with a fraction of the problems
> leading to complete data loss because the vendor wouldn't even bother
> answering questions unless you were bringing them millions in revenue.
>
> Unless you REALLY REALLY need the extra performance (and are sure that
> you get it) I'd suggest software RAID.
>
> That said, don't most of the big database servers have a "work directly
> from the partitions and balance data as you see fit" mode? Because for
> them filesystems are just overhead.
>
> Cheers,
> - Martin
>
>
>
> _______________________________________________
> Bristol mailing list
> Bristol@mailman.lug.org.uk
> https://mailman.lug.org.uk/mailman/listinfo/bristol
>
>
>
> _______________________________________________
> Bristol mailing list
> Bristol@mailman.lug.org.uk
> https://mailman.lug.org.uk/mailman/listinfo/bristol
_______________________________________________
Bristol mailing list
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--
"Science is a differential equation. Religion is a boundary condition."
Alan Turing
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