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LMON Unresponsive Executing a Cross Instance Call to Offline an ASM Disk (Doc ID 2090742.1)

Last updated on AUGUST 04, 2018

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 11.2 to 12.1]
Information in this document applies to any platform.


1. This is an Extended RAC configuration with two sites (Site A and B).

2. Customer is testing a site loss scenario, where the machines and disk array in the remote site are powered off

3. In one of the instances LMON is executing a Cross Instance Call (CIC) to offline a disk, which causes LMON to be unresponsive. A LMHB trace shows:


*** 2015-10-18 15:43:42.664
loadavg : 2.94 3.50 2.54
System user time: 0.01 sys time: 0.00 context switch: 46580
Memory (Avail / Total) = 205120.65M / 257569.06M
Swap (Avail / Total) = 16896.00M /  16896.00M
0 S o_edsdp  14967     1  0  80   0 - 7795331 poll_s 14:58 ?      00:00:11 ora_lmon_INST1
Short stack dump:


 - note that LMON is executing ksbcic(), which was from kfiDiskOffline().

 4. Since LMON was unresponsive this instance was terminated with the ORA-29770:

Sun Oct 18 15:43:02 2015
CKPT (ospid: 15064) waits for event 'enq: XR - database force logging' for 208 secs.
Sun Oct 18 15:43:22 2015
LGWR (ospid: 15050) waits for event 'log file parallel write' for 209 secs.
Sun Oct 18 15:43:40 2015
LMON (ospid: 14967) waits for event 'control file parallel write' for 202
Errors in file <PATCH>/trace/INST1_lmhb_15018.trc (incident=1016746):
ORA-29770: global enqueue process LMON (OSID 14967) is hung for more than 200 seconds



 Customer is making the disk array in the remote site unavailable, in order to test a site loss scenario.


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