<p class="MsoNormal" style="margin: 0in 0in 10pt;"><span style="font-size: small; font-family: Calibri;">Enterprise Flash Drive is the term that EMC uses for the new Solid State Disk or Flash Solid State Disk.<span style="mso-spacerun: yes;">  </span>EFD’s are supported for all Clariion Models with the release of Flare 28.<span style="mso-spacerun: yes;">  </span>The maximum number of Enterprise Flash Drives supported is different for each model.<span style="mso-spacerun: yes;">  </span>The CX4-960 and CX4-80 will be able to support up to 60 EFD’s.<span style="mso-spacerun: yes;">  </span>The CX4-240 and CX4-120 will support up to 30 EFD’s.</span></p>
<p class="MsoNormal" style="margin: 0in 0in 10pt;"><span style="font-size: small; font-family: Calibri;"><!--more-->The minimum amount of EFD’s required is 2 drives.<span style="mso-spacerun: yes;">  </span>The capacity and speed of the drives are 73 GB with a 4Gb/s FC interface.<span style="mso-spacerun: yes;">  </span>Formatted capacity will be 67.68 GB and available capacity after binding LUNs will be 66.60 GB.<span style="mso-spacerun: yes;">  </span>EFD’s are not required to have a dedicated bus or enclosure, However, the ordering and Manufacturing Process will structure them independently.<span style="mso-spacerun: yes;">  </span>For new arrays the EFD’s will be placed on busses without other drive types whenever possible.<span style="mso-spacerun: yes;">  </span>Configuration adjustments may be made at the time of installation.<span style="mso-spacerun: yes;"> </span></span></p>
<p class="MsoNormal" style="margin: 0in 0in 10pt;"><span style="font-size: small;"><span style="font-family: Calibri;">Any existing 4 Gb/s enclosures will support the new EFD’s specifically model CX4-4PDAE and CX3-4PDAE.<span style="mso-spacerun: yes;">  </span>Also EFD’s and other FC drives can be in the same enclosure and SATA drives must be in separate enclosures. </span></span></p>
<p class="MsoNormal" style="margin: 0in 0in 10pt;"><span style="font-size: small; font-family: Calibri;">A couple of things that can or cannot be done with EFD’s are as follows.<span style="mso-spacerun: yes;">  </span>EFD’s cannot be mixed with FC drives in the same RAID Group.<span style="mso-spacerun: yes;">  </span>All RAID configurations supported for Fibre Channel drives are also supported for EFD’s.<span style="mso-spacerun: yes;">  </span>LUN migration is supported on an EFD RAID Group.<span style="mso-spacerun: yes;">  </span>Virtual Provisioning is not supported as of the Q4 08 FLARE release 28.<span style="mso-spacerun: yes;">  </span>EFD LUN’s can be used with NQM policies/goals.<span style="mso-spacerun: yes;">  </span>MetaLUNs are supported but FC drives cannot be in the same MetaLUN.<span style="mso-spacerun: yes;">  </span>All array based replication technologies (SnapView, SAN Copy and MirrorView) are supported. EFDs can also be used in Reserved LUN Pools, Clone Private LUNs and Write Intent Logs. However, EFDs might show less benefit because of the kind of I/O profiles that these applications generate. </span></p>
<p class="MsoNormal" style="margin: 0in 0in 10pt;"><span style="font-size: small; font-family: Calibri;">Improvements provided by EFDs in replication environments will not likely be enough to be cost-effective.<span style="mso-spacerun: yes;">  </span>Use of EFD’s as vault drives are not supported.<span style="mso-spacerun: yes;">  </span>When using the ASAP throttle rate for rebuilds in a CLARiiON, the performance bottleneck is generally the back-end bus rather than the drives themselves. This is because of the larger and sequential nature of I/O during rebuilds (not an ideal I/O profile for EFDs). So, using EFDs in place of FC drives will not result in significant performance benefits in rebuild rates. When other throttle rates (HIGH, MEDIUM or LOW) are used, the rebuild rate is controlled by the array and having a faster drive will not be of benefit.<span style="mso-spacerun: yes;">    </span>CLARiiON cache will be turned OFF by default for LUNs bound on EFDs. You can manually turn the cache on using Navisphere. This is consistent with the upcoming recommended best practices for EFDs (there may be some exceptions to this which will be addressed in the Best Practices document).</span></p>
<p class="MsoNormal" style="margin: 0in 0in 10pt;"><span style="font-size: small; font-family: Calibri;">EFDs will show the highest improvements versus FC drives in the following situations: </span></p>

<ul style="margin-top: 0in;" type="disc">
	<li class="MsoNormal"><span style="font-size: small; font-family: Calibri;">Multi-threaded applications.</span></li>
	<li class="MsoNormal"><span style="font-size: small; font-family: Calibri;">Small block I/Os.</span></li>
	<li class="MsoNormal"><span style="font-size: small; font-family: Calibri;">Primarily read workloads.</span></li>
	<li class="MsoNormal"><span style="font-size: small; font-family: Calibri;">Applications where the drive performance is the limiting factor. </span></li>
</ul>
<p class="MsoNormal" style="margin: 0in 0in 10pt;"><span style="font-size: small; font-family: Calibri;"> </span><span style="font-size: small; font-family: Calibri;">This leads to a strategy focusing on hotspots by application need, such as the file system, database, and application metadata and map areas. In addition to the characteristics mentioned previously, applications requiring low response times and high IOPS will show the highest performance improvement from EFDs. OLTP applications are well suited for EFD use</span></p>
<p class="MsoNormal" style="margin: 0in 0in 10pt;"><span style="font-size: small; font-family: Calibri;"> </span></p>