pg.ddx.io pgsql-performance@postgresql.org mailing list archive
help / color / mirror / Atom feedWhich RAID Controllers to pick/avoid?
16+ messages / 10 participants
[nested] [flat]
* Which RAID Controllers to pick/avoid?
@ 2011-02-02 23:15 Dan Birken <birken@gmail.com>
2011-02-03 02:00 ` Re: Which RAID Controllers to pick/avoid? Craig Ringer <craig@postnewspapers.com.au>
2011-02-03 05:46 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
2011-02-03 14:57 ` Re: Which RAID Controllers to pick/avoid? Mario Weilguni <roadrunner6@gmx.at>
0 siblings, 3 replies; 16+ messages in thread
From: Dan Birken @ 2011-02-02 23:15 UTC (permalink / raw)
To: pgsql-performance
I'm setting up a dedicated linux postgres box with 2x300GB 15k SAS drive in
a RAID 1, though if future load dictates we would like to be able to upgrade
to RAID 10. The hosting provider offers the following options for a RAID
controller (all are the same price):
ADAPTEC 3405 RAID Controller
ADAPTEC 4800 RAID Controller
LSI MegaRaid 8308 RAID Controller
ADAPTEC 5405 RAID Controller
ADAPTEC 5405Z RAID Controller
ADAPTEC 5805 RAID Controller
ADAPTEC 5805Z RAID Controller
However, they can't guarantee that any particular RAID controller would be
in stock when they are building the machine, so basically I would like to
know if any of these cards are sufficiently better or worse than the others
that I should either a) wait for a particular card or b) avoid a card.
Also, I am planning on replicating this box to a standby machine with
streaming replication. Given this, is there any reason not to use the write
cache on the RAID controller assuming it has battery backup? My though
being even in a worst case scenario if the BBU fails and the master DB gets
corrupted, the standby (not using any write cache) would still be ok sans a
few seconds of data (assuming the replication was keeping up, which would be
monitored).
-Dan
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
@ 2011-02-03 02:00 ` Craig Ringer <craig@postnewspapers.com.au>
2011-02-03 06:02 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
2 siblings, 1 reply; 16+ messages in thread
From: Craig Ringer @ 2011-02-03 02:00 UTC (permalink / raw)
To: Dan Birken <birken@gmail.com>; +Cc: pgsql-performance
On 03/02/11 07:15, Dan Birken wrote:
> However, they can't guarantee that any particular RAID controller would
> be in stock when they are building the machine, so basically I would
> like to know if any of these cards are sufficiently better or worse than
> the others that I should either a) wait for a particular card or b)
> avoid a card.
I don't know the Adaptec parts above (I avoid them these days) but AFAIK
the LSI is at least OK.
Whatever RAID controller you get, make sure you have a battery backup
unit (BBU) installed so you can safely enable write-back caching.
Without that, you might as well use software RAID - it'll generally be
faster (and cheaper) than HW RAID w/o a BBU.
I get great results with Linux software RAID 10 on my Pg server - but
then, I'm not loading it particularly hard. (I continually wish the `md'
driver could use a PCIe/SATA battery-backed DRAM cache, because it'd be
capable of massively outperforming most HW raid implementation if only
it could offer safe write-back caching using persistent cache.)
> Also, I am planning on replicating this box to a standby machine with
> streaming replication. Given this, is there any reason not to use the
> write cache on the RAID controller assuming it has battery backup? My
> though being even in a worst case scenario if the BBU fails and the
> master DB gets corrupted, the standby (not using any write cache) would
> still be ok sans a few seconds of data (assuming the replication was
> keeping up, which would be monitored).
That sounds about right. The standby would be fine, the master would be
totaled.
If you're doing write-back caching without a BBU and things go down,
it's not going to be neatly time-warped back a few seconds. Your DB will
be corrupted, possibly massively. One big advantage of write-back
caching is that it lets the controller batch and re-order writes for
higher disk throughput as well as lower latencies at the app level. The
cost of that is that you lose the safety of ordered writes to WAL then
heap; it's quite possible for physical media writes to hit the heap
before the WAL, for newer writes to hit the WAL before older writes, etc
etc. Because of the cache, the OS and Pg never see or care about the
crazily inconsistent state of the actual disk media - unless the cache
is lost, in which case you're screwed.
Assume that a BBU failure will require restoration from a backup or from
a standby server. If you can't afford that, you should operate in
write-through cache mode, possibly using synchronous commit and/or
commit delay options if you can afford a few seconds data loss on crash.
--
System & Network Administrator
POST Newspapers
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 02:00 ` Re: Which RAID Controllers to pick/avoid? Craig Ringer <craig@postnewspapers.com.au>
@ 2011-02-03 06:02 ` Scott Marlowe <scott.marlowe@gmail.com>
2011-02-06 09:39 ` Re: Which RAID Controllers to pick/avoid? Royce Ausburn <royce.ml@inomial.com>
0 siblings, 1 reply; 16+ messages in thread
From: Scott Marlowe @ 2011-02-03 06:02 UTC (permalink / raw)
To: Craig Ringer <craig@postnewspapers.com.au>; +Cc: Dan Birken <birken@gmail.com>; pgsql-performance
On Wed, Feb 2, 2011 at 7:00 PM, Craig Ringer
<craig@postnewspapers.com.au> wrote:
> Whatever RAID controller you get, make sure you have a battery backup
> unit (BBU) installed so you can safely enable write-back caching.
> Without that, you might as well use software RAID - it'll generally be
> faster (and cheaper) than HW RAID w/o a BBU.
Recently we had to pull our RAID controllers and go to plain SAS
cards. While random access dropped a bit, sequential throughput
skyrocketed, saturating the 4 lane cable we use. 4x300Gb/s =
1200Gb/s or right around 1G of data a second off the array. VERY
impressive.
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 02:00 ` Re: Which RAID Controllers to pick/avoid? Craig Ringer <craig@postnewspapers.com.au>
2011-02-03 06:02 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
@ 2011-02-06 09:39 ` Royce Ausburn <royce.ml@inomial.com>
2011-02-06 09:55 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
0 siblings, 1 reply; 16+ messages in thread
From: Royce Ausburn @ 2011-02-06 09:39 UTC (permalink / raw)
To: Scott Marlowe <scott.marlowe@gmail.com>; +Cc: Craig Ringer <craig@postnewspapers.com.au>; Dan Birken <birken@gmail.com>; pgsql-performance
> On Wed, Feb 2, 2011 at 7:00 PM, Craig Ringer
> <craig@postnewspapers.com.au> wrote:
>> Whatever RAID controller you get, make sure you have a battery backup
>> unit (BBU) installed so you can safely enable write-back caching.
>> Without that, you might as well use software RAID - it'll generally be
>> faster (and cheaper) than HW RAID w/o a BBU.
>
> Recently we had to pull our RAID controllers and go to plain SAS
> cards. While random access dropped a bit, sequential throughput
> skyrocketed, saturating the 4 lane cable we use. 4x300Gb/s =
> 1200Gb/s or right around 1G of data a second off the array. VERY
> impressive.
This is really surprising. Software raid generally outperform hardware raid without BBU? Why is that? My company uses hardware raid quite a bit without BBU and have never thought to compare with software raid =/
Thanks!
--Royce
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 02:00 ` Re: Which RAID Controllers to pick/avoid? Craig Ringer <craig@postnewspapers.com.au>
2011-02-03 06:02 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
2011-02-06 09:39 ` Re: Which RAID Controllers to pick/avoid? Royce Ausburn <royce.ml@inomial.com>
@ 2011-02-06 09:55 ` Scott Marlowe <scott.marlowe@gmail.com>
2011-02-06 12:15 ` Re: Which RAID Controllers to pick/avoid? david@lang.hm
0 siblings, 1 reply; 16+ messages in thread
From: Scott Marlowe @ 2011-02-06 09:55 UTC (permalink / raw)
To: Royce Ausburn <royce.ml@inomial.com>; +Cc: Craig Ringer <craig@postnewspapers.com.au>; Dan Birken <birken@gmail.com>; pgsql-performance
On Sun, Feb 6, 2011 at 2:39 AM, Royce Ausburn <royce.ml@inomial.com> wrote:
>
>> On Wed, Feb 2, 2011 at 7:00 PM, Craig Ringer
>> <craig@postnewspapers.com.au> wrote:
>>> Whatever RAID controller you get, make sure you have a battery backup
>>> unit (BBU) installed so you can safely enable write-back caching.
>>> Without that, you might as well use software RAID - it'll generally be
>>> faster (and cheaper) than HW RAID w/o a BBU.
>>
>> Recently we had to pull our RAID controllers and go to plain SAS
>> cards. While random access dropped a bit, sequential throughput
>> skyrocketed, saturating the 4 lane cable we use. 4x300Gb/s =
>> 1200Gb/s or right around 1G of data a second off the array. VERY
>> impressive.
>
>
> This is really surprising. Software raid generally outperform hardware raid without BBU? Why is that? My company uses hardware raid quite a bit without BBU and have never thought to compare with software raid =/
For raw throughtput it's not uncommon to beat a RAID card whether it
has a battery backed cache or not. If I'm wiriting a 200G file to the
disks, a BBU cache isn't gonna make that any faster, it'll fill up in
a second and then it's got to write to disk. BBU Cache are for faster
random writes, and will handily beat SW RAID. But for raw large file
read and write SW RAID is the fastest thing I've seen.
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 02:00 ` Re: Which RAID Controllers to pick/avoid? Craig Ringer <craig@postnewspapers.com.au>
2011-02-03 06:02 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
2011-02-06 09:39 ` Re: Which RAID Controllers to pick/avoid? Royce Ausburn <royce.ml@inomial.com>
2011-02-06 09:55 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
@ 2011-02-06 12:15 ` david@lang.hm
0 siblings, 0 replies; 16+ messages in thread
From: david@lang.hm @ 2011-02-06 12:15 UTC (permalink / raw)
To: Scott Marlowe <scott.marlowe@gmail.com>; +Cc: Royce Ausburn <royce.ml@inomial.com>; Craig Ringer <craig@postnewspapers.com.au>; Dan Birken <birken@gmail.com>; pgsql-performance
On Sun, 6 Feb 2011, Scott Marlowe wrote:
> On Sun, Feb 6, 2011 at 2:39 AM, Royce Ausburn <royce.ml@inomial.com> wrote:
>>
>>> On Wed, Feb 2, 2011 at 7:00 PM, Craig Ringer
>>> <craig@postnewspapers.com.au> wrote:
>>>> Whatever RAID controller you get, make sure you have a battery backup
>>>> unit (BBU) installed so you can safely enable write-back caching.
>>>> Without that, you might as well use software RAID - it'll generally be
>>>> faster (and cheaper) than HW RAID w/o a BBU.
>>>
>>> Recently we had to pull our RAID controllers and go to plain SAS
>>> cards. While random access dropped a bit, sequential throughput
>>> skyrocketed, saturating the 4 lane cable we use. 4x300Gb/s =
>>> 1200Gb/s or right around 1G of data a second off the array. VERY
>>> impressive.
>>
>>
>> This is really surprising. Software raid generally outperform hardware
>> raid without BBU? Why is that? My company uses hardware raid quite a
>> bit without BBU and have never thought to compare with software raid =/
>
> For raw throughtput it's not uncommon to beat a RAID card whether it
> has a battery backed cache or not. If I'm wiriting a 200G file to the
> disks, a BBU cache isn't gonna make that any faster, it'll fill up in
> a second and then it's got to write to disk. BBU Cache are for faster
> random writes, and will handily beat SW RAID. But for raw large file
> read and write SW RAID is the fastest thing I've seen.
>
keep in mind that hardware raide with BBU is safer than software raid.
since the updates to the drives do not all happen at the same time, there
is a chance that a write to software raid may have happened on some drives
and not others when the system crashes.
with hardware raid and BBU, the controller knows what it was trying to
write where, and if it didn't get the scknowledgement, it will complete
the write when it comes up again.
but with software raid you will have updates some part of the array and
not others. this will result in a corrupted stripe in the array.
David Lang
From pgsql-performance-owner@postgresql.org Sun Feb 6 09:04:39 2011
Received: from maia.hub.org (maia-5.hub.org [200.46.204.29])
by mail.postgresql.org (Postfix) with ESMTP id C84291336B42
for <pgsql-performance-postgresql.org@mail.postgresql.org>; Sun, 6 Feb 2011 09:04:38 -0400 (AST)
Received: from mail.postgresql.org ([200.46.204.86])
by maia.hub.org (mx1.hub.org [200.46.204.29]) (amavisd-maia, port 10024)
with ESMTP id 14200-03
for <pgsql-performance-postgresql.org@mail.postgresql.org>;
Sun, 6 Feb 2011 13:04:32 +0000 (UTC)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from locust.cns.vt.edu (locust.cns.vt.edu [198.82.169.14])
by mail.postgresql.org (Postfix) with ESMTP id 228971337B49
for <pgsql-performance@postgresql.org>; Sun, 6 Feb 2011 09:04:31 -0400 (AST)
Received: by locust.cns.vt.edu (Postfix, from userid 986)
id 55FC2118DD1; Sun, 6 Feb 2011 08:04:30 -0500 (EST)
Date: Sun, 6 Feb 2011 08:04:30 -0500
From: Ray Stell <stellr@cns.vt.edu>
To: felix <crucialfelix@gmail.com>
Cc: sthomas@peak6.com,
"pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Subject: Re: Really really slow select count(*)
Message-ID: <20110206130430.GC24627@cns.vt.edu>
References: <AANLkTinAJcm5A+i1O_R87aiYyu8N2OWgoaL9RfR=tUR9@mail.gmail.com> <4D4C138C.7010304@2ndquadrant.com> <4D4C1555.40209@peak6.com> <AANLkTikrS5JkJDMjAXpcRWRnuLbX+MHB=CWb_mFa9qb-@mail.gmail.com> <4D4C2AC3.5020804@peak6.com> <AANLkTin8ndBSU9ZJ2uAdnvYQ7oLBg2S04bqAXn-s5qv+@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <AANLkTin8ndBSU9ZJ2uAdnvYQ7oLBg2S04bqAXn-s5qv+@mail.gmail.com>
User-Agent: Mutt/1.5.17 (2007-11-01)
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Spam-Status: No, hits=-1.91 tagged_above=-10 required=5 tests=BAYES_00=-1.9,
T_RP_MATCHES_RCVD=-0.01
X-Spam-Level:
X-Archive-Number: 201102/253
X-Sequence-Number: 42391
On Sun, Feb 06, 2011 at 11:48:50AM +0100, felix wrote:
> BRUTAL
>
Did the changes work in your test environment?
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
@ 2011-02-03 05:46 ` Greg Smith <greg@2ndquadrant.com>
2011-02-03 05:58 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
2 siblings, 1 reply; 16+ messages in thread
From: Greg Smith @ 2011-02-03 05:46 UTC (permalink / raw)
To: Dan Birken <birken@gmail.com>; +Cc: pgsql-performance
Dan Birken wrote:
> ADAPTEC 3405 RAID Controller
> ADAPTEC 4800 RAID Controller
The 3405 and 4800 are two of Adaptec's older cards with only 128MB of
cache on them. Those are on the slow side compared to the others listed.
> LSI MegaRaid 8308 RAID Controller
> ADAPTEC 5405 RAID Controller
> ADAPTEC 5405Z RAID Controller
> ADAPTEC 5805 RAID Controller
> ADAPTEC 5805Z RAID Controller
The LSI cards are some of the most popular and known to work well with
PostgreSQL ones around.
I've recently tested a system based on the 5405, and as much as I've
hated Adaptec controllers in the past I have to admit this latest line
from them is pretty solid. My own benchmarks and the others I've seen
suggest it's easily capable of keeping up with the LSI and Areca
controllers Adaptec used to be seriously outrun by. See
http://www.tomshardware.com/reviews/adaptec-serial-controllers,1806-14.html
for example.
The "Z" variations use their "Zero-Maintenance Cache" instead of a
standard battery-backup unit; that's a small amount of flash memory and
a supercap, similar to the good caches on SSD:
http://www.adaptec.com/NR/rdonlyres/7FD8C372-8231-4727-B12B-5ABF79D9325C/0/6514_Series5Z_1_7.pdf
5405 has 256MB of cache, the others 512MB.
The 5405 and 5805 models do have a known problem where they overheat if
you don't have enough cooling in the server box, with the 5805 seeming
to be the bigger source of such issues. See the reviews at
http://www.newegg.com/Product/Product.aspx?Item=N82E16816103099 for
example. Scott Marlowe was griping recently about a similar issue in
some of the LSI models, too. I suspect it's a problem impacting several
of the larger RAID cards that use the big Intel IOP processors for their
RAID computations, given that's the part with the heatsink on it.
Quick summary: avoid the Adaptec 3405 and 4800. Rest are decent
cards. Just make sure you monitor the temperatures in your case (and
the card too if arcconf lets you, I haven't checked for that yet) if you
end up with a 5405/5805.
--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us
"PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 05:46 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
@ 2011-02-03 05:58 ` Scott Marlowe <scott.marlowe@gmail.com>
2011-02-03 06:15 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
0 siblings, 1 reply; 16+ messages in thread
From: Scott Marlowe @ 2011-02-03 05:58 UTC (permalink / raw)
To: Greg Smith <greg@2ndquadrant.com>; +Cc: Dan Birken <birken@gmail.com>; pgsql-performance
On Wed, Feb 2, 2011 at 10:46 PM, Greg Smith <greg@2ndquadrant.com> wrote:
> example. Scott Marlowe was griping recently about a similar issue in some
> of the LSI models, too. I suspect it's a problem impacting several of the
> larger RAID cards that use the big Intel IOP processors for their RAID
> computations, given that's the part with the heatsink on it.
Specifically the LSI 8888 in a case that gave very low amounts of air
flow over the RAID card. The case right above the card was quite hot,
and the multilane cable was warm enough to almost burn my fingers when
I pulled it out the back. I'm not sure any RAID card would have
survived there, but the LSI 8888 LP definitely did not.
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 05:46 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
2011-02-03 05:58 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
@ 2011-02-03 06:15 ` Greg Smith <greg@2ndquadrant.com>
2011-02-03 06:30 ` Re: Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 06:31 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
0 siblings, 2 replies; 16+ messages in thread
From: Greg Smith @ 2011-02-03 06:15 UTC (permalink / raw)
To: Scott Marlowe <scott.marlowe@gmail.com>; +Cc: Dan Birken <birken@gmail.com>; pgsql-performance
Scott Marlowe wrote:
> On Wed, Feb 2, 2011 at 10:46 PM, Greg Smith <greg@2ndquadrant.com> wrote:
>
>> example. Scott Marlowe was griping recently about a similar issue in some
>> of the LSI models, too. I suspect it's a problem impacting several of the
>> larger RAID cards that use the big Intel IOP processors for their RAID
>> computations, given that's the part with the heatsink on it.
>>
>
> Specifically the LSI 8888 in a case that gave very low amounts of air
> flow over the RAID card. The case right above the card was quite hot,
> and the multilane cable was warm enough to almost burn my fingers whe
Interesting...that shoots down my theory. Now that I check, the LSI
8888 uses their SAS1078 controller, which is based on a PowerPC 440
processor--it's not one of the Intel IOP processors at all. The 8308
Dan has as an option is using the very popular Intel IOP333 instead,
which is also used in some Areca 1200 series cards (1220/1230/1260).
The Adaptec 5405 and 5805 cards both use the Intel IOP348, as does the
Areca 1680. Areca puts a fan right on it; Adaptec does not. I
suspect the only reason the 5805 cards have gotten more reports of
overheating than the 5405 ones is just because having more drives
typically connected increases their actual workload. I don't think
there's actually any difference between the cooling situation between
the two otherwise.
--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us
"PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 05:46 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
2011-02-03 05:58 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
2011-02-03 06:15 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
@ 2011-02-03 06:30 ` Dan Birken <birken@gmail.com>
2011-02-03 06:45 ` Re: Which RAID Controllers to pick/avoid? Magnus Hagander <magnus@hagander.net>
2011-02-03 15:02 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
1 sibling, 2 replies; 16+ messages in thread
From: Dan Birken @ 2011-02-03 06:30 UTC (permalink / raw)
To: Greg Smith <greg@2ndquadrant.com>; +Cc: Scott Marlowe <scott.marlowe@gmail.com>; pgsql-performance
Thank you everybody for the detailed answers, the help is well appreciated.
A couple of follow-up questions:
- Is the supercap + flash memory considered superior to the BBU in practice?
Is that type of system well tested?
- Is the linux support of the LSI and Adaptec cards comparable?
-Dan
On Wed, Feb 2, 2011 at 10:15 PM, Greg Smith <greg@2ndquadrant.com> wrote:
> Scott Marlowe wrote:
>
> On Wed, Feb 2, 2011 at 10:46 PM, Greg Smith <greg@2ndquadrant.com> <greg@2ndquadrant.com> wrote:
>
>
> example. Scott Marlowe was griping recently about a similar issue in some
> of the LSI models, too. I suspect it's a problem impacting several of the
> larger RAID cards that use the big Intel IOP processors for their RAID
> computations, given that's the part with the heatsink on it.
>
>
> Specifically the LSI 8888 in a case that gave very low amounts of air
> flow over the RAID card. The case right above the card was quite hot,
> and the multilane cable was warm enough to almost burn my fingers whe
>
>
> Interesting...that shoots down my theory. Now that I check, the LSI 8888
> uses their SAS1078 controller, which is based on a PowerPC 440
> processor--it's not one of the Intel IOP processors at all. The 8308 Dan
> has as an option is using the very popular Intel IOP333 instead, which is
> also used in some Areca 1200 series cards (1220/1230/1260).
>
> The Adaptec 5405 and 5805 cards both use the Intel IOP348, as does the
> Areca 1680. Areca puts a fan right on it; Adaptec does not. I suspect
> the only reason the 5805 cards have gotten more reports of overheating than
> the 5405 ones is just because having more drives typically connected
> increases their actual workload. I don't think there's actually any
> difference between the cooling situation between the two otherwise.
>
>
> --
> Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
> PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us
> "PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books
>
>
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 05:46 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
2011-02-03 05:58 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
2011-02-03 06:15 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
2011-02-03 06:30 ` Re: Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
@ 2011-02-03 06:45 ` Magnus Hagander <magnus@hagander.net>
2011-02-03 08:11 ` Re: Which RAID Controllers to pick/avoid? Joachim Worringen <worringen@gmail.com>
1 sibling, 1 reply; 16+ messages in thread
From: Magnus Hagander @ 2011-02-03 06:45 UTC (permalink / raw)
To: Dan Birken <birken@gmail.com>; +Cc: Greg Smith <greg@2ndquadrant.com>; Scott Marlowe <scott.marlowe@gmail.com>; pgsql-performance
On Thu, Feb 3, 2011 at 07:30, Dan Birken <birken@gmail.com> wrote:
> Thank you everybody for the detailed answers, the help is well appreciated.
> A couple of follow-up questions:
> - Is the supercap + flash memory considered superior to the BBU in practice?
I think it's considered about equivalent.
The advantages of the flash one are no battery maintenance (=no
downtime every <n> years to replace it) and no "timeout" if you loose
power (but the battery backed ones are usually good for 48 hours or
so, and if you don't have a server up by then...)
> Is that type of system well tested?
Yes.
> - Is the linux support of the LSI and Adaptec cards comparable?
Can't comment on that one, sorry.
--
Magnus Hagander
Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 05:46 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
2011-02-03 05:58 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
2011-02-03 06:15 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
2011-02-03 06:30 ` Re: Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 06:45 ` Re: Which RAID Controllers to pick/avoid? Magnus Hagander <magnus@hagander.net>
@ 2011-02-03 08:11 ` Joachim Worringen <worringen@gmail.com>
0 siblings, 0 replies; 16+ messages in thread
From: Joachim Worringen @ 2011-02-03 08:11 UTC (permalink / raw)
To: pgsql-performance
Am 03.02.2011 07:45, schrieb Magnus Hagander:
> On Thu, Feb 3, 2011 at 07:30, Dan Birken<birken@gmail.com> wrote:
>> - Is the linux support of the LSI and Adaptec cards comparable?
>
> Can't comment on that one, sorry.
We dropped LSI in favour of Adaptec for exactly this reason. We run
hundreds of machines in remote locations, and always again had problems
with LSI regarding support of new controller models and kernel versions
(esp. on system installation), and because of occasional kernel panics
triggers by the LSI driver. The Adaptec-support integrated into the
Linux kernel source tree does a flawless job here.
On the other hand, Adaptec is not perfect as well: when we attached a
24-drive SAS storage unit to a 5805Z, it failed to properly handle drive
failures in this unit. We are using an LSI again there, which so far
works well...
Joachim
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 05:46 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
2011-02-03 05:58 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
2011-02-03 06:15 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
2011-02-03 06:30 ` Re: Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
@ 2011-02-03 15:02 ` Greg Smith <greg@2ndquadrant.com>
1 sibling, 0 replies; 16+ messages in thread
From: Greg Smith @ 2011-02-03 15:02 UTC (permalink / raw)
To: Dan Birken <birken@gmail.com>; +Cc: Scott Marlowe <scott.marlowe@gmail.com>; pgsql-performance
Dan Birken wrote:
> - Is the supercap + flash memory considered superior to the BBU in
> practice? Is that type of system well tested?
The main risk is that it's a pretty new approach. The standard BBU
setup has been used for a long time now; this whole flash+supercap thing
has only showed up in the last couple of years. Theoretically it's
better; the #1 weakness of the old battery setup was only surviving an
outage of a few days, and storing to flash doesn't have that issue.
It's just got the usual risks of something new.
> - Is the linux support of the LSI and Adaptec cards comparable?
Seems to be. The latest versions of Adaptec's arcconf utility even
provide about the same quality of command-line tools as LSI's megactl,
after being behind in that area for a while. Only quirk, and I can't
say where this was the manufacturer of the box or not because they
installed the base OS, is that the 5405 setup I saw didn't turn off the
write caches on the individual drives of the system. That's the
standard safe practice and default for the LSI cards.
--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us
"PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 05:46 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
2011-02-03 05:58 ` Re: Which RAID Controllers to pick/avoid? Scott Marlowe <scott.marlowe@gmail.com>
2011-02-03 06:15 ` Re: Which RAID Controllers to pick/avoid? Greg Smith <greg@2ndquadrant.com>
@ 2011-02-03 06:31 ` Scott Marlowe <scott.marlowe@gmail.com>
1 sibling, 0 replies; 16+ messages in thread
From: Scott Marlowe @ 2011-02-03 06:31 UTC (permalink / raw)
To: Greg Smith <greg@2ndquadrant.com>; +Cc: Dan Birken <birken@gmail.com>; pgsql-performance
On Wed, Feb 2, 2011 at 11:15 PM, Greg Smith <greg@2ndquadrant.com> wrote:
> Scott Marlowe wrote:
>
> On Wed, Feb 2, 2011 at 10:46 PM, Greg Smith <greg@2ndquadrant.com> wrote:
>
>
> example. Scott Marlowe was griping recently about a similar issue in some
> of the LSI models, too. I suspect it's a problem impacting several of the
> larger RAID cards that use the big Intel IOP processors for their RAID
> computations, given that's the part with the heatsink on it.
>
>
> Specifically the LSI 8888 in a case that gave very low amounts of air
> flow over the RAID card. The case right above the card was quite hot,
> and the multilane cable was warm enough to almost burn my fingers whe
>
> Interesting...that shoots down my theory. Now that I check, the LSI 8888
> uses their SAS1078 controller, which is based on a PowerPC 440
> processor--it's not one of the Intel IOP processors at all. The 8308 Dan
> has as an option is using the very popular Intel IOP333 instead, which is
> also used in some Areca 1200 series cards (1220/1230/1260).
>
> The Adaptec 5405 and 5805 cards both use the Intel IOP348, as does the Areca
> 1680. Areca puts a fan right on it; Adaptec does not. I suspect the only
> reason the 5805 cards have gotten more reports of overheating than the 5405
> ones is just because having more drives typically connected increases their
> actual workload. I don't think there's actually any difference between the
> cooling situation between the two otherwise.
The LSI 8888 has a fan right on it. But it was just moving 90C air
around in place.
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
@ 2011-02-03 14:57 ` Mario Weilguni <roadrunner6@gmx.at>
2 siblings, 0 replies; 16+ messages in thread
From: Mario Weilguni @ 2011-02-03 14:57 UTC (permalink / raw)
To: pgsql-performance
Am 03.02.2011 00:15, schrieb Dan Birken:
> I'm setting up a dedicated linux postgres box with 2x300GB 15k SAS
> drive in a RAID 1, though if future load dictates we would like to be
> able to upgrade to RAID 10. The hosting provider offers the following
> options for a RAID controller (all are the same price):
Adaptec at least has good tools for managing the controller, and
performance in our RAID-1 (DB) and RAID-5 setups (Files) is very good. I
don't think you can do wrong with the Adaptec controllers.
Can't say much regarding LSI, but avoid cheap HP controllers.
^ permalink raw reply [nested|flat] 16+ messages in thread
* Re: Which RAID Controllers to pick/avoid?
@ 2011-02-03 09:54 Glyn Astill <glynastill@yahoo.co.uk>
0 siblings, 0 replies; 16+ messages in thread
From: Glyn Astill @ 2011-02-03 09:54 UTC (permalink / raw)
To: Dan Birken <birken@gmail.com>; Greg Smith <greg@2ndquadrant.com>; +Cc: pgsql-performance
--- On Thu, 3/2/11, Greg Smith <greg@2ndquadrant.com> wrote:
> The 5405 and 5805 models do have a known problem where they overheat if
> you don't have enough cooling in the server box, with the 5805 seeming
> to be the bigger source of such issues. See the reviews at
> http://www.newegg.com/Product/Product.aspx?Item=N82E16816103099 for
> example. Scott Marlowe was griping recently about a similar issue in
> some of the LSI models, too. I suspect it's a problem impacting
> several of the larger RAID cards that use the big Intel IOP processors
> for their RAID computations, given that's the part with the heatsink on
> it.
> Quick summary: avoid the Adaptec 3405 and 4800. Rest are decent
> cards. Just make sure you monitor the temperatures in your case (and
> the card too if arcconf lets you, I haven't checked for that yet) if
> you end up with a 5405/5805.
I can attest to the 5805 and 5805Z cards running a little hot, the ones we're running tend to run in the high 60s and low 70s Celsius with fairly good airflow over them.
I've been running some 5805s for 3 years now, and 5805Zs for a year and they've been really good, stable, fast cards. I monitor everything on them (including temperature) with nagios and a simple script that uses the arcconf utility.
Glyn
^ permalink raw reply [nested|flat] 16+ messages in thread
end of thread, other threads:[~2011-02-06 12:15 UTC | newest]
Thread overview: 16+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2011-02-02 23:15 Which RAID Controllers to pick/avoid? Dan Birken <birken@gmail.com>
2011-02-03 02:00 ` Craig Ringer <craig@postnewspapers.com.au>
2011-02-03 06:02 ` Scott Marlowe <scott.marlowe@gmail.com>
2011-02-06 09:39 ` Royce Ausburn <royce.ml@inomial.com>
2011-02-06 09:55 ` Scott Marlowe <scott.marlowe@gmail.com>
2011-02-06 12:15 ` david@lang.hm
2011-02-03 05:46 ` Greg Smith <greg@2ndquadrant.com>
2011-02-03 05:58 ` Scott Marlowe <scott.marlowe@gmail.com>
2011-02-03 06:15 ` Greg Smith <greg@2ndquadrant.com>
2011-02-03 06:30 ` Dan Birken <birken@gmail.com>
2011-02-03 06:45 ` Magnus Hagander <magnus@hagander.net>
2011-02-03 08:11 ` Joachim Worringen <worringen@gmail.com>
2011-02-03 15:02 ` Greg Smith <greg@2ndquadrant.com>
2011-02-03 06:31 ` Scott Marlowe <scott.marlowe@gmail.com>
2011-02-03 14:57 ` Mario Weilguni <roadrunner6@gmx.at>
2011-02-03 09:54 Re: Which RAID Controllers to pick/avoid? Glyn Astill <glynastill@yahoo.co.uk>
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox