HP LTO6 -Drives Reboot or Disappear/Reappear of CISCO Switches

Asset ID:	1-72-1637138.1
Update Date:	2017-05-22
Keywords:

Solution Type Problem Resolution Sure

Solution 1637138.1 : HP LTO6 -Drives Reboot or Disappear/Reappear of CISCO Switches

Applies to:

3rd-Party Hardware - Version Not Applicable to Not Applicable [Release N/A]
HP LTO6 Tape Drive - Version All Versions to All Versions [Release All Releases]
Information in this document applies to any platform.

Symptoms

This was received from CISCO. This was an issue for everyone when they went to 8 Gig (not an issue just would receive messages in the logs as a disconnect and reconnect).

The HP LTO6 drives were connected to the Cisco switch via a 4Gb blade. Device ONLY disappeared from the host, then reappear. Seen in VAR MESSAGE FILE in the Host Software.

Customer example of problem:
root@sacux201 # grep PWWN /var/adm/messages
Mar 6 13:50:13 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(6)::N_x Port with D_ID=1000e, PWWN=500104f000a0b1ac disappeared from fabric
Mar 6 13:50:57 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(6)::N_x Port with D_ID=1000e, PWWN=500104f000a0b1ac reappeared in fabric
Mar 6 13:51:41 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(6)::N_x Port with D_ID=1000e, PWWN=500104f000a0b1ac disappeared from fabric
Mar 6 15:22:16 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(6)::N_x Port with D_ID=1000e, PWWN=500104f000a0b1ac reappeared in fabric
Mar 7 03:53:26 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 disappeared from fabric
Mar 7 03:53:29 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 reappeared in fabric
Mar 7 05:18:08 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 disappeared from fabric
Mar 7 05:18:11 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 reappeared in fabric
Mar 7 05:25:24 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 disappeared from fabric
Mar 7 05:25:27 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 reappeared in fabric
Mar 7 08:33:22 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 disappeared from fabric
Mar 7 08:33:25 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 reappeared in fabric
Mar 7 09:12:07 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 disappeared from fabric
Mar 7 09:12:10 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 reappeared in fabric
Mar 7 10:26:19 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f000b, PWWN=500104f000a0b1e2 disappeared from fabric
Mar 7 12:39:58 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 disappeared from fabric
Mar 7 12:40:01 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 reappeared in fabric
Mar 7 14:13:39 sacux201 fctl: [ID 517869 kern.warning] WARNING: fp(11)::N_x Port with D_ID=2f0012, PWWN=500104f000a0b239 disappeared from fabric

Changes

CISCO switch code - It did not get implemented until 5.2.(8).

Cause

Here is the T11 specification’s on this matter and the notes at the bottom from CISCO.

www.t11.org

Unlike TCP/IP communication, Fibre Channel requires that all devices in a Fabric to communicate at all times, even when the device in question is neither sending or receiving data.

The two most common frames (Primitives) being sent are R_RDY (Receive Ready) and IDLE. IDLE is a Fill Word used to take up space along the wire. These two frames alternate R_RDY and IDLE, R_RDY and IDLE, until data receive or transmit commands occur. IDLE can also be found when a device is waiting for a response from another device.

Prior to the creation of the 8 Gig standard, the T11 sanctioning body set IDLE as the required Fill Word, with ARB(ff) as an option. Effectively, 95% of FC manufacturers chose IDLE as the Fill Word.

When the 8 Gig standard was ratified, ARB(ff) was selected, instead of IDLE, as a means to help lower EMR emissions. Using ARB(ff) as a Fill Word, instead of IDLE, was established in FC-PI-4 sec 5.8 that a port operating at 8G FC shall use scrambling/ELP.

FC-PI-4 Rev 8.0 states:
5.8 Frame scrambling and emission lowering protocol 8GFC shall use the frame scrambling as stated in FC-FS-2 AM1 (reference [5]) and emission lowering protocol as stated in FC-FS-2 (reference [4]). 1GFC, 2GFC, and 4GFC do not use scrambling.

FC-FS-3 Rev 0.70 states:
5.2.4.9 ARB(ff) ARB(ff) is a Primitive Signal used to maintain link synchronization on links using Emission Lowering Protocol (ELP). ARB(ff) shall be treated the same as Idle. ARB(ff) shall be transmitted on links using Emission Lowering Protocol during periods of time when frames, other Primitive Signals, or Primitive Sequences are not required to be transmitted.

Extracted from Cisco Release notes starting at 5.2.6

The following guidelines applies to a downgrade from Cisco MDS NX-OS Release 5.2(6):

• Cisco NX-OS Release 5.2(6) supports IDLE as a fill word for the switchport fill-pattern command.

Releases earlier than Release 5.2(6) supported only the ARBFF fill word. As a result, when you downgrade from Cisco NX-OS Release 5.2(6) to an earlier release that does not support the IDLE fill word, the following syntax error occurs:

Syntax error while parsing 'switchport fill-pattern IDLE speed 8000'(NOT AN ERROR CAN BE IGNORED)

You won’t see this error unless you go dig in the log files. IT’s NOT a HARD ERROR.

Solution

This fix was not implemented until CISCO code 5.2.(8) .

Install CISCO firmware accordingly.

Attachments

This solution has no attachment