I upgraded the latest version. I have 3 nodes. and one of 3 nodes got following errors.
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: couldn't create file for mmap
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: qb_rb_open

ve2-request-2643-28396-1022: Too many open files (24)
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: shm connection FAILED: Too many open files (24)
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: Error in connection setup (2643-28396-1022): Too many open files (24)
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: couldn't open file /dev/shm/qb-pve2-request-2643-28396-1022-data: Too many open files (24)
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: couldn't open file /var/run/qb-pve2-request-2643-28396-1022-data: Too many open files (24)
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: couldn't create file for mmap
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: qb_rb_open

ve2-request-2643-28396-1022: Too many open files (24)
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: shm connection FAILED: Too many open files (24)
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: Error in connection setup (2643-28396-1022): Too many open files (24)
Aug 28 05:08:24 pxmx03 pve-ha-lrm[28396]: updating service status from manager failed: Too many open files
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: couldn't open file /dev/shm/qb-pve2-request-2643-28396-1022-data: Too many open files (24)
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: couldn't open file /var/run/qb-pve2-request-2643-28396-1022-data: Too many open files (24)
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: couldn't create file for mmap
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: qb_rb_open

ve2-request-2643-28396-1022: Too many open files (24)
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: shm connection FAILED: Too many open files (24)
Aug 28 05:08:24 pxmx03 pmxcfs[2643]: [libqb] error: Error in connection setup (2643-28396-1022): Too many open files (24)
Aug 28 05:08:24 pxmx03 pve-ha-lrm[28396]: updating service status from manager failed: Too many open files