Troubleshooting MapR loopbacknfs POSIX Client Upgrades

If you are having difficulty upgrading the MapR POSIX client, it might be due to a shared-memory-segment lock.

About this task

If the mapr-loopbacknfs service fails to start after an upgrade, use the following steps to determine if a shared-memory-segment lock was the cause of the failure:

Procedure

  1. Open the loopbacknfs.log file. The loopbacknfs.log file is in the following directory: /usr/local/mapr-loopbacknfs/logs/
  2. Check for the following string: Create/Attach to shm failed
  3. If the string is present, perform the following steps:
    1. Run the following command to identify the shmid of the lock: ipcs -m | grep 0x0000161c
    2. Run the following command to remove the lock:ipcrm -m <shm id>
    3. Start the mapr-loopbacknfs service.