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From: Emmanuel Florac <eflorac@intellique.com>
To: Dave Chinner <david@fromorbit.com>
Cc: Dave Hall <kdhall@binghamton.edu>,
	stan@hardwarefreak.com, "xfs@oss.sgi.com" <xfs@oss.sgi.com>
Subject: Re: XFS/LVM/Multipath on a single RAID volume
Date: Wed, 25 Feb 2015 12:49:46 +0100	[thread overview]
Message-ID: <20150225124946.1784b9ca@harpe.intellique.com> (raw)
In-Reply-To: <20150224223344.GE4251@dastard>

Le Wed, 25 Feb 2015 09:33:44 +1100
Dave Chinner <david@fromorbit.com> écrivait:

> > On an existing array based on similar but slightly slower hardware,
> > I'm getting miserable performance.  The bottleneck seems to be on
> > the server side.  For specifics, the array is laid out as a single
> > 26TB volume and attached by a single 3Gbps SAS.   
> 
> So, 300MB/s max throughput.
> 

Ah yes, maybe external RAID controllers can only use one SAS channel
out of the 4 available, that would definitely limit performance badly.
This limitation don't apply to internal RAID controllers (Adaptec, LSI,
Areca) driving a JBOD though.

I'll do a short digression on external storage enclosures: they're
mostly useful to provide redundant controllers. If you're using only one
controller, cheap ones (such as infortrend, Promise and the like) will
always perform poorly compared to a modern PCIe RAID controller.

High-end storage enclosures (DotHill, NetApp, etc) with high-bandwidth
attachments (FC or IB) provide better performance AND redundancy, but
at a hefty price.

So if you want fast, cheap arrays, definitely use Adaptec/LSI/Areca and
simple JBOD chassis like supermicro's.

-- 
------------------------------------------------------------------------
Emmanuel Florac     |   Direction technique
                    |   Intellique
                    |	<eflorac@intellique.com>
                    |   +33 1 78 94 84 02
------------------------------------------------------------------------

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  parent reply	other threads:[~2015-02-25 11:49 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-13 18:11 xfs_fsr, sunit, and swidth Dave Hall
2013-03-13 23:57 ` Dave Chinner
2013-03-14  0:03 ` Stan Hoeppner
     [not found]   ` <514153ED.3000405@binghamton.edu>
2013-03-14 12:26     ` Stan Hoeppner
2013-03-14 12:55       ` Stan Hoeppner
2013-03-14 14:59         ` Dave Hall
2013-03-14 18:07           ` Stefan Ring
2013-03-15  5:14           ` Stan Hoeppner
2013-03-15 11:45             ` Dave Chinner
2013-03-16  4:47               ` Stan Hoeppner
2013-03-16  7:21                 ` Dave Chinner
2013-03-16 11:45                   ` Stan Hoeppner
2013-03-25 17:00                   ` Dave Hall
2013-03-27 21:16                     ` Stan Hoeppner
2013-03-29 19:59                       ` Dave Hall
2013-03-31  1:22                         ` Dave Chinner
2013-04-02 10:34                           ` Hans-Peter Jansen
2013-04-03 14:25                           ` Dave Hall
2013-04-12 17:25                             ` Dave Hall
2013-04-13  0:45                               ` Dave Chinner
2013-04-13  0:51                               ` Stan Hoeppner
2013-04-15 20:35                                 ` Dave Hall
2013-04-16  1:45                                   ` Stan Hoeppner
2013-04-16 16:18                                   ` Dave Chinner
2015-02-22 23:35                                     ` XFS/LVM/Multipath on a single RAID volume Dave Hall
2015-02-23 11:18                                       ` Emmanuel Florac
2015-02-24 22:04                                         ` Dave Hall
2015-02-24 22:33                                           ` Dave Chinner
     [not found]                                             ` <54ED01BC.6080302@binghamton.edu>
2015-02-24 23:33                                               ` Dave Chinner
2015-02-25 11:49                                             ` Emmanuel Florac [this message]
2015-02-25 11:21                                           ` Emmanuel Florac
2013-03-28  1:38                     ` xfs_fsr, sunit, and swidth Dave Chinner

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