Limits revisited

There were more limits changed in regard of open files has been changed with as well. The change took place in SRU27.

• rlim_fd_cur has been increased from 256 pre-SRU27 to 4095 now.
• rlim_fd_max has been decreased from 65536 to 65535.
• rlim_fd_sys which is the source of of the system-wide max-file-descriptor setting has been made dependent on the memory size in its default. To cite the documentation.

  Starting with Oracle Solaris 11.4 SRU 27, calculated based on physmem to be approximately 65K per gigabyte of memory. The value is rounded up to the nearest value of (2^N)-1.

The change in regard of rlim_fd_sys can be shown best with a short prctl -i process $$. Please have a look at the last line. At first the output of a pre-SRU 27 system.

process.max-file-descriptor
        basic             256       -   deny                                 -
        privileged      65,5K       -   deny                                 -
        system          2,15G     max   deny

Now let’s do this again on a SRU30 system:

process.max-file-descriptor
        basic           4,09K       -   deny                                 -
        privileged      65,5K       -   deny                                 -
        system           131K     max   deny

For more information please consult the Tunable Parameters Reference Guide’s chapter about general I/O parameters