To upgrade to NX-OS Release 4.2(1a) from SAN-OS Release 3.2(3a) or earlier, first upgrade to SAN-OS Release 3.3(x) and then upgrade to NX-OS Release 4.2(1a).

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<p class="pB1_Body1">Use the following guidelines when upgrading to Cisco MDS NX-OS Release 4.2(1a):</p>

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<p class="pBu1_Bullet1">•<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="19" height="2" />Install and configure dual supervisor modules.</p>

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<p class="pBu1_Bullet1">•<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="19" height="2" />Issue the <strong>show install all impact</strong> <em>upgrade-image</em> CLI command to determine if your upgrade will be nondisruptive.</p>

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<p class="pBu1_Bullet1">•<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="19" height="2" />Be aware that you need to enable Telnet following the upgrade.</p>

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<p class="pBu1_Bullet1">•<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="19" height="2" />Follow the recommended guidelines for upgrading a Cisco MDS 9124 or MDS 9134 Switch.<a name="wp217472"></a></p>

•<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="19" height="2" />Follow the guidelines for upgrading a single supervisor switch.

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<p class="pBu1_Bullet1">•<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="19" height="2" />Make note of the information concerning SANTap when performing upgrades on a Cisco MDS 9222i switch.</p>

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<p class="pBu1_Bullet1">•<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="19" height="2" />Be aware of the impact of an upgrade on VSAN 4079 if you are upgrading from SAN-OS Release 3.x to NX-OS 4.2(1a).<a name="wp217473"></a></p>

•<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="19" height="2" />Be aware that some features impact whether an upgrade is disruptive or nondisruptive:

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<p class="pBu2_Bullet2">–<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="17" height="2" /><strong>Fibre Channel Ports</strong>:<strong> </strong>Traffic on Fibre Channel ports<strong> </strong>can be nondisruptively upgraded.<a name="wp410136"></a></p>

–<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="17" height="2" /><strong>SSM</strong>: Intelligent services traffic on the SSM, such as SANTap, NASB, and FC write acceleration, is disrupted during an upgrade. SSM Fibre Channel traffic is not.

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<p class="pBu2_Bullet2">–<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="17" height="2" /><strong>Gigabit Ethernet Ports</strong>:<strong> </strong>Traffic on Gigabit Ethernet ports is<strong> </strong>disrupted during an upgrade or downgrade. This includes IPS modules and the Gigabit Ethernet ports on the MPS-14/2 module, the MSM-18/4 module, and the MDS 9222i switch. Those nodes that are members of VSANs traversing an FCIP ISL are impacted, and a fabric reconfiguration occurs. iSCSI initiators connected to the Gigabit Ethernet ports lose connectivity to iSCSI targets while the upgrade is in progress.</p>

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<p class="pBu2_Bullet2">–<img src="http://blogs.egroup.jasonmangone.com/i/templates/blank.gif" border="0" alt="" width="17" height="2" /><strong>Inter-VSAN Routing (IVR)</strong>: With IVR enabled, you must follow additional steps if you are upgrading from Cisco SAN-OS Release 2.1.(1a), 2.1(1b), or 2.1.(2a).</p>