When troubleshooting Fibre Channel adapter issues on AIX (or VIOS), I often use the fcstat command to assist me in the process. The command may display error numbers similar to the following:

 

$ fcstat fcs0

 

Error opening device: /dev/fscsi0

errno: 00000045

 

The error number (errno) displayed can (in some cases) be used to identify the root cause of a problem. In the example above, the error number is 45. This number is in hex. If we convert this to decimal, the number is 69. Now, if we look for 69 in the /usr/include/errno.h file (on AIX), we discover that this error number relates to a "Network is down" event.

 

# fcstat fcs0

Error opening device: /dev/fscsi0

errno: 00000045

 

# echo "ibase=16; 45"|bc

69

 

# grep 69 /usr/include/errno.h

#define ENETDOWN        69      /* Network is down */

 

The AIX error report (errpt or errlog on VIOS) also tells me that there's some type of link error. This helps me focus my investigation toward the most likely problem area. In this case, I suspect either a physical link or cable problem between my FC adapter and the SAN switch.

 

IDENTIFIER TIMESTAMP  T C RESOURCE_NAME  DESCRIPTION

7BFEEA1F   1116121816 T H fcs0           LINK ERROR

 

# errpt -aN fcs0 | grep -p Desc

...

Description

LINK ERROR

 

We can use the same process for other errors displayed by the fcstat command. For example:

 

# fcstat fcs0

Error opening device: /dev/fscsi0

errno: 00000046

 

# echo "ibase=16; 46"|bc

70

 

# grep 70 /usr/include/errno.h

#define ENETUNREACH     70      /* Network is unreachable */

 

This particular error may direct us to the solution outlined in the following tech note:

 

Fibre channel workspace takes over 2 minutes to load but returns no data

http://www-01.ibm.com/support/docview.wss?uid=swg21600064

 

 

fcstat Command (AIX 6.1)

http://www.ibm.com/support/knowledgecenter/ssw_aix_61/com.ibm.aix.cmds2/fcstat.htm

 

fcstat Command (AIX 7.1)

http://www.ibm.com/support/knowledgecenter/ssw_aix_71/com.ibm.aix.cmds2/fcstat.htm

 

fcstat Command (AIX 7.2)

http://www.ibm.com/support/knowledgecenter/ssw_aix_72/com.ibm.aix.cmds2/fcstat.htm

 

 

 

Tags:  gibson vios fcstat chris aix errno