<p dir="ltr">That's been my use as well until now. I've got a support ticket open with avago.</p>
<div class="gmail_extra"><br><div class="gmail_quote">On Sep 2, 2016 5:19 PM, "Lightner, Jeffrey" <<a href="mailto:JLightner@dsservices.com">JLightner@dsservices.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Most of the MegaRaid cards I’ve seen are made by LSI/Avago (including the Dell PERC/SAS which are OEMed from LSI/Avago).<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">During POST when it find the BIOS of these cards it usually gives you a Ctrl-R option to go into that for config. I don’t know whether that config allows
you to change individual drive cache setup. Typically I don’t muck with such setups on the assumption the card was already optimized. I’ve only used it for creating/modifying the RAID layout.
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Once they’re in a RAID presented by the card you’re not going to see the individual drives at OS level – you’ll just see the entire RAID set(s) as individual
drive(s). e.g. If you had created a RAID1 of 2 disks for OS then a RAID5 for remaining disks you’re only going to see /dev/sda and /dev/sdb at OS level.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:ale-bounces@ale.org" target="_blank">ale-bounces@ale.org</a> [mailto:<a href="mailto:ale-bounces@ale.org" target="_blank">ale-bounces@ale.org</a>]
<b>On Behalf Of </b>Jim Kinney<br>
<b>Sent:</b> Friday, September 02, 2016 4:13 PM<br>
<b>To:</b> Atlanta Linux Enthusiasts - Yes! We run Linux!<br>
<b>Subject:</b> [ale] hdparm and RAID cards<u></u><u></u></span></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">How the $(^*#!!! do I use hdparm to enable write caching on a giant pile of drives that make up a hardware RAID 6 array?<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">I can peek through the controller with smartctl for health monitoring. The RAID controller (MegaRAID) has a tool to see that each drive has a N/A status for hardware cache (these drives all have a large multi-MB cache).<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">I _really_ don't want to have to convert all 28 drives to RAID0 so I can get a /dev/sdx node for hdparm.<u></u><u></u></p>
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<pre>-- <u></u><u></u></pre>
<pre>James P. Kinney III<u></u><u></u></pre>
<pre><u></u> <u></u></pre>
<pre>Every time you stop a school, you will have to build a jail. What you<u></u><u></u></pre>
<pre>gain at one end you lose at the other. It's like feeding a dog on his<u></u><u></u></pre>
<pre>own tail. It won't fatten the dog.<u></u><u></u></pre>
<pre>- Speech 11/23/1900 Mark Twain<u></u><u></u></pre>
<pre><u></u> <u></u></pre>
<pre><a href="http://heretothereideas.blogspot.com/" target="_blank">http://heretothereideas.<wbr>blogspot.com/</a><u></u><u></u></pre>
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