Isolation of switch from the stack

[svven]

From a 3 switch Summit stack,One of the switch has been moved out of stack. I am unable to find the reason why the switch has been moved out, can someone guide me to find the cause of the issue?

[Tony_Thornton]

Also, if you have an external syslog server configured for the stack, you can check the log history for slot 2 to see if any messages were logged just before the reboot. Some log messages are deleted after a switch reboots.

[Patrick_Voss]

See if you can console into the stack and also provide the output to "show stacking" and "show slot detail" from the current master.

[MANAS_BEHERA]

Hello,

It is not clear based on the logs. Please share below commands output.

show log messages nvram from master switch.
show log messages nvram from the failed switch.

[svven]

It's an running stack all of sudden it got disappear.

From the master switch i could able to see the below logs

01/14/2016 08:02:58.32 Slot-1: BACKUP NODE (Slot-2) DOWN
01/14/2016 07:51:49.18 Slot-1: Previous message repeated 102 additional times in the last 662 second(s)
01/14/2016 07:51:43.53 Slot-1: Login passed for user admin through serial slot-1
01/14/2016 07:51:42.68 Slot-1: BACKUP NODE (Slot-2) DOWN
01/14/2016 07:45:25.61 Slot-1: Previous message repeated 58 additional times in the last 371 second(s)
01/14/2016 07:45:22.53 Slot-1: User admin logout from telnet (195.0.0.101)
01/14/2016 07:45:19.11 Slot-1: BACKUP NODE (Slot-2) DOWN
01/14/2016 06:14:33.42 Slot-1: Previous message repeated 835 additional times in the last 5439 second(s)

-> show switch

SysName: Coddissia_ONM_IPSwitch
SysLocation: COIMBATORE-CODISSIA
SysContact: ERICSSON
System MAC: 02:04:96:51:A1:38
System Type: X450a-48t (Stack)

SysHealth check: Enabled (Normal)
Recovery Mode: All
System Watchdog: Enabled

Current Time: Thu Jan 14 08:02:22 2016
Timezone: [Auto DST Disabled] GMT Offset: 330 minutes, name is India.
Boot Time: Tue Oct 11 20:12:27 2011
Boot Count: 10
Next Reboot: None scheduled
System UpTime: 1555 days 11 hours 49 minutes 55 seconds

Slot: Slot-1 * Slot-2
------------------------ ------------------------
Current State: MASTER BACKUP

Image Selected: primary
Image Booted: primary

In Secondary switch (Slot 2)

show switch

SysName: Coddissia_ONM_IPSwitch
SysLocation: COIMBATORE-CODISSIA
SysContact: ERICSSON
System MAC: 02:04:96:51:A1:38
System Type: X450a-48t (Stack)

SysHealth check: Enabled (Normal)
Recovery Mode: All
System Watchdog: Enabled

Current Time: Thu Jan 14 08:36:36 2016
Timezone: [Auto DST Disabled] GMT Offset: 330 minutes, name is India.
Boot Time: Tue Oct 11 20:12:26 2011
Boot Count: 11
Next Reboot: None scheduled
System UpTime: 1555 days 12 hours 10 minutes 5 seconds

Slot: Slot-2 * No Backup
------------------------ ------------------------
Current State: MASTER

Image Selected: primary
Image Booted: primary

01/12/2016 22:19:09.43 Slot-2: Failover occurred ()
01/12/2016 22:19:08.63 Slot-2: Node failover initialized slot 2.
01/12/2016 22:19:08.32 Slot-2: Port 1:48 is Down, remove from aggregator 1:48