Ulimit: openfiles: cannotmodifylimit: Operationnotpermi

When switching from a root user to an oracle user, a message indicating ulimit: openfiles: cannotmodifylimit: Operationnotpermitte is displayed. Literal Meaning

When switching from a root user to an oracle user, a message indicating ulimit: open files: cannot modify limit: Operation not permitte is displayed. Literal Meaning

When switching from a root user to an Oracle user, a message indicating ulimit: open files: cannot modify limit: Operation not permitte is displayed. Literally, opening a file is restricted. On the same server, this situation should not occur if there is only one single Oracle instance and there are few data files. Multiple instances may encounter this situation. Because multiple instances are owned by Oracle users, the total number of files that Oracle users can operate on is the total number of files of all instances. If the limit is exceeded, an error message is returned.

1. fault description
-- Prompt appears when switching from root to oracle
Oracle @ v2013db02u:/u02/database> su-oracle
Password:
-Bash: ulimit: open files: cannot modify limit: Operation not permitted
-Bash: ulimit: open files: cannot modify limit: Operation not permitted

A. view the limits. conf configuration file.
Oracle @ v2013db02u: ~> More/etc/security/limits. conf
#/Etc/security/limits. conf
#
# Each line describes a limit for a user in the form:
#
#
#
# Where:
# Can be:
#-An user name
#-A group name, with @ group syntax
#-The wildcard *, for default entry
#-The wildcard %, can be also used with % group syntax,
# For maxlogin limit
#
# Can have the two values:
#-"Soft" for enforcing the soft limits
#-"Hard" for enforcing hard limits
#
# Can be one of the following:
#-Core-limits the core file size (KB)
#-Data-max data size (KB)
#-Fsize-maximum filesize (KB)
#-Memlock-max locked-in-memory address space (KB)
#-Nofile-max number of open files
#-Rss-max resident set size (KB)
#-Stack-max stack size (KB)
#-Cpu-max CPU time (MIN)
#-Nproc-max number of processes
#-As-address space limit
#-Maxlogins-max number of logins for this user
#-Maxsyslogins-max number of logins on the system
#-Priority-the priority to run user process
#-Locks-max number of file locks the user can hold
#-Sigpending-max number of pending signals
#-Msgqueue-max memory used by POSIX message queues (bytes)
#-Nice-max nice priority allowed to raise
#-Rtprio-max realtime priority
#
#
#

# * Soft core 0
# * Hard rss 10000
# @ Student hard nproc 20
# @ Faculty soft nproc 20
# @ Faculty hard nproc 50
# Ftp hard nproc 0
# @ Student-maxlogins 4

# End of file

-- The comments in the limits. conf file provide a good description, that is, we can configure different items in soft and hare Based on users or groups.
-- Soft is the soft limit, while hard is the hard limit. The user can exceed the soft value, but cannot exceed the hard value. Generally, soft is smaller than hard.
-- The preceding file does not provide any information for Oracle users, and the wildcard * is also commented out.
-- Since this server is a new UAT server, Oracle software installs and configures Infra. As we can see from the above, it should be that Infra forgets or ignores the configuration value of this file.
-- When the number of database instances is small and the number of opened files is small, there is no problem. As the running instance increases, the phenomenon will emerge.

-- View the resource allocation restrictions of the current user.
-- For resource restrictions, you can also use the ulimit command to limit the user's resource allocation, such as the number of opened files, the maximum number of processes, and the CPU usage time.
-- You can use the command ulimit-a to view the current user's limit limits (ulimit usage: man ulimit)

B. view the resource limits of the current user
Oracle @ v2013db02u: ~> Ulimit-
Core file size (blocks,-c) 0
Data seg size (kbytes,-d) unlimited
File size (blocks,-f) unlimited
Pending signals (-I) 540672
Max locked memory (kbytes,-l) 32
Max memory size (kbytes,-m) unlimited
Open files (-n) 1024 --> the number of opened files is limited to 1024, which is obviously not enough.
Pipe size (512 bytes,-p) 8
POSIX message queues (bytes,-q) 819200
Stack size (kbytes,-s) 8192
Cpu time (seconds,-t) unlimited
Max user processes (-u) 16384
Virtual memory (kbytes,-v) unlimited
File locks (-x) unlimited