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Date:      Thu, 30 Jun 2005 17:18:15 -0400
From:      "Simon" <simon@optinet.com>
To:        "Danny Howard" <dannyman@toldme.com>
Cc:        Bob Bomar <bob@ibsd.us>, "questions@freebsd.org" <questions@freebsd.org>, "hardware@freebsd.org" <hardware@freebsd.org>
Subject:   Re: RAID Cards
Message-ID:  <20050630211444.19C6343D48@mx1.FreeBSD.org>
In-Reply-To: <20050630205744.GN33728@ratchet.nebcorp.com>

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It's not only CPU factor, I don't trust software RAID. As for monitoring, I can tell
whether or not a drive is dead via SAFTE chip and all SCSI RAID cards support
SAFTE and a proper SCSI server would have SAFTE support. As for SATA, the
3ware cards have 3dm tool to monitor the array.

-Simon

On Thu, 30 Jun 2005 13:57:44 -0700, Danny Howard wrote:

>On Thu, Jun 30, 2005 at 04:48:18PM -0400, Simon wrote:
>
>> Just because there is no monitoring tool available due to lack of
>> support, doesn't mean the card itself is bad. I much prefer hardware
>> implementation than software.  True hardware RAID frees up a lot of
>> CPU time if you have heavy IO and software just can't keep up if you
>> utilize CPU intensive apps.
>
>When you have a dual Xeon setup, you are more likely to be bound by disk
>than CPU.
>
>And a RAID that you can not monitor is a BAD RAID.
>
>The biggest thing that bothers me about my current environment is that I
>have remotely-deployed machines with RAIDs and I can't tell when a disk
>goes bad unless I visit the datacenter.  Last time I was there I had a
>RAID card throwing an audible alarm, even though nothing was wrong.  I
>had to reboot a critical system to fix that.
>
>If you can implement it in software, then its worth the headaches you'll
>avoid with hardware dependencies.  If you're concerned at CPU overhead,
>spend the cash you would have spent on a RAID card and upgrade your CPU.
>
>Sincerely,
>-danny
>
>-- 
>http://dannyman.toldme.com/
>





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