<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">Michal,</p>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">I think you need to revise your testing method. Let me explain.</p>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">Based on my understandings:</p>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><b>3 FE servers and one storage system</b></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 19px;"><b></b><br></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 19px;"><b></b><br></p>
<ul>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span>~4500 MiB/s from 8 RAID groups using XFS (one XFS per one RAID group) and parallel fio test.</li>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span> one FS across all 8 RAID groups and we observed performance drop down to ~3300</li>
</ul>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 19px;"><b></b><br></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><b>The test you are running is a non-clustered fs versus a clustered fs.</b></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 19px;"><b></b><br></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><b>XFS,</b></p>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<ul>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><b><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span>8 XFS filesystems.</b></li>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span>Each FS has it own Array and independent Meta, not shared between nodes</li>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span>Array will see sequential IO for each array and will be able to aggregate IO’s and prefetch on read.</li>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span>No lock traffic between nodes</li>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span>Didn’t mention for the FIO runs is this <b>one node </b>or the<b> three nodes</b> with 8 XFS fs’s spread across?</li>
</ul>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><b>GPFS Clustered Filesystem</b></p>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<ul>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><b><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span>1 GPFS Filesystem (fs0) In this case</b></li>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span>Parallel Filesystem with shared Meta and access</li>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span>Lock and Meta traffic across nodes</li>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span><b>GPFS Stripes across NSD, 8 in this case.</b> So <b>each fio stream will appear random at the storage when combined.</b> ( this very different from your 8x XFS test)</li>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span><b>Array logic will not see this as sequential </b>and delivery a much lower performance from a sequential point of view as each stream is intermixed.</li>
</ul>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 19px;"><b> </b></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><b>What to do,</b></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 19px;"><b></b><br></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><b>Try </b></p>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<ol>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">8 individual gpfs FS with your FIO test like XFS test. Ie do like for like. <b>8x XFS versus 8x GPFS</b>. From an array perspective same io pattern.</li>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">1 gpfs FS and 1 Array and matching 1 FIO ( then x8 result)</li>
</ol>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 19px;"><b></b><br></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><b>PS: You haven’t mention the type of array used? Sometimes the following is important.</b></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 19px;"><b></b><br></p>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<ul>
<li style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"><span style="font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Menlo; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;"></span>Disable prefetch at the array. This causes the array to sometimes over work the backend due to incorrectly fetching data that is never used causing extra io and cache displacement. Ie GPFS aggressively prefetches which triggers the array to do further prefetch and both are not used.</li>
</ul>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 15px;"><br></p>
<p style="margin: 0px 0px 2px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 16px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal; min-height: 19px;"><b></b><br></p>
<p style="margin: 0px; font-style: normal; font-variant-caps: normal; font-stretch: normal; font-size: 13px; line-height: normal; font-family: "Helvetica Neue"; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">Dale</p></body></html>