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Subject: RE: RAID 5 performance problems
From: Ezra Nugroho <ezran@goshen.edu>
To: Jonathan Vardy <jonathan@explainerdc.com>
Cc: "Peter L. Ashford" <ashford@sdsc.edu>,
       Jonathan Vardy <jonathanv@explainerdc.com>,
       Stephan van Hienen <raid@a2000.nu>, linux-raid@vger.kernel.org,
       linux-kernel@vger.kernel.org
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> hdc: host protected area => 1
> hdc: 234441648 sectors (120034 MB) w/2048KiB Cache, CHS=232581/16/63,
> UDMA(33)


Your hdc is still running at udma(33). This is also part of the raid,
right? This will slow the whole thing down since in raid 5 write is done
to all disks simultaneously. Before the system finishes writing to the
slow drive, the write is not done yet.