While tuning the RAPCache server (by adding named caches or increasing the sizes of existing caches), Linux users may find that the server cannot start.
The memory allocated to the server is large enough to accommodate the additional cache size, and the operating system level parameter SHMMAX (the maximum size in bytes for a shared memory segment) is also large enough, but the server does not restart.
The problem may be that the operating system level parameter SHMALL, the system-wide maximum of shared memory pages, is not large enough. Increase the value of SHMALL in /proc/sys/kernel/shmall.
Modifying /proc/sys/kernel/shmall requires root permission.