Forum: Storage & Hardrives
August 10th 09, 06:40 PM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 6
Views: 1,007
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Forum: Storage & Hardrives
August 10th 09, 01:01 AM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 6
Views: 1,007
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Forum: Storage & Hardrives
August 8th 09, 07:47 PM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 6
Views: 1,007
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Forum: Storage & Hardrives
August 7th 09, 01:30 PM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 6
Views: 1,007
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Forum: Storage & Hardrives
May 1st 09, 04:45 AM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
Unimpressive performance of large MD raid (LONG!)
Hi all
here are details. Actually most news are not good, but I appear to have
found one bottleneck: LVM, see below.
I confirm numbers the given previously, plus: (the following benchmarks
are...
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Forum: Storage & Hardrives
April 30th 09, 03:00 AM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
Unimpressive performance of large MD raid
Hi all,
based on your suggestions I have been testing lots of stuff: xfs, ext2,
raw lvm device reads and writes, effect of bs in dd, disk scheduler,
noatime... Interesting stuff is coming out, and...
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Forum: Storage & Hardrives
April 28th 09, 11:55 PM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
Unimpressive performance of large MD raid
Hi everybody,
Thanks for your suggestions
I have seen the suggestions by Guy and Patrick to raise the bs for dd. I
had already tried various values for this, up to a very large value, and
I even...
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Forum: Storage & Hardrives
April 24th 09, 03:33 PM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
Unimpressive performance of large MD raid
This guy
http://lists.freebsd.org/pipermail/freebsd-fs/2008-September/005170.html
is doing basically the same as I am doing with software raid done with
ZFS in freebsd (raid-Z2 is basically...
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Forum: Storage & Hardrives
April 24th 09, 12:00 PM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
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Forum: Storage & Hardrives
April 24th 09, 11:09 AM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
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Forum: Storage & Hardrives
April 24th 09, 10:56 AM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
Unimpressive performance of large MD raid
Bill Todd wrote:
That said, it's possible that the Linux system file cache interacts
poorly with md in terms of how it destages data to the array - e.g., if
it hands data to md in chunks that...
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Forum: Storage & Hardrives
April 24th 09, 10:23 AM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
Unimpressive performance of large MD raid
David Brown wrote:
I did spend a few minutes in Google trying to find detailed
information about md's RAID-6 implementation but got nowhere.
...
There is a lot more information about...
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Forum: Storage & Hardrives
April 24th 09, 10:10 AM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
Unimpressive performance of large MD raid
David Schwartz wrote:
It is the bottleneck, it's just not a CPU bottleneck, it's an I/O
bottleneck.
With an 8x PCI-e bus there should be space for 2 GB/sec transfer...
The problem is simply...
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Forum: Storage & Hardrives
April 23rd 09, 03:37 PM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
Unimpressive performance of large MD raid
David Brown wrote:
If you have so many disks connected, did you consider having at least
one as a hot spare?
Of course! We have 4 spares shared among all the arrays.
Secondly, did you...
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Forum: Storage & Hardrives
April 23rd 09, 01:45 PM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
Unimpressive performance of large MD raid
David Schwartz wrote:
How mind-blowingly awful. I'm sure there must be some set of
circumstances that justify such a ridiculously poor setup, but I don't
know what they could possibly be....
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Forum: Storage & Hardrives
April 23rd 09, 11:51 AM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
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Forum: Storage & Hardrives
April 22nd 09, 08:29 PM Posted to comp.os.linux.development.system,comp.arch.storage
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Replies: 32
Views: 2,198
Unimpressive performance of large MD raid
Hi there,
we have a big "storage" computer: dual Xeon (8 cores
total) with lots of disks partly connected to a 3ware 9650SE controller
and partly to the SATA/SAS controllers in the...
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