The Problem We have had some instances where it seemed that starting rac databases through sqlplus caused performance issues (high load on database server ). Restarting the nodes using srvctl seemed to resolve the performance issue. "Is there any difference between using srvctl vs using sqlplus for starting or stopping one or more database nodes."? The Solution The Differences between SQLPLUS and SRVCTL There are some differences between the use of SQLPLUS and SRVCTL utilities. - Both … [Read more...] about Difference between using srvctl vs using sqlplus for start/stop one or more Oracle Database Instances
Archives for November 2018
How To Change Timezone for Oracle Grid Infrastructure
This post illustrates how to change timezone setting for Grid Infrastructure after installation. Note: To check the current time zone on Linux, use the command: "timedatectl | grep 'Time zone'" To check the current time zone on Windows, use the command: "systeminfo | findstr /C:"Time Zone"" Grid Time Zone Setting Once OS default timezone is changed, make sure: For 11.2.0.1, shell environment variable TZ is set correctly for grid user and root. For 11.2.0.2 and above, TZ entry in … [Read more...] about How To Change Timezone for Oracle Grid Infrastructure
How to Set the TimeZone in Solaris 10,11
The Ask In Solaris Operating System (OS), where is the default timezone set, and how can it be changed? Solaris 11 OS and above 1. The default timezone is defined as a property of the "svc:/system/timezone:default" SMF service: # svcs timezone STATE STIME FMRI online Aug_22 svc:/system/timezone:default # svcprop timezone:default |grep localtime timezone/localtime astring US/Eastern 2. To change the default timezone, use the svccfg and then refresh the service … [Read more...] about How to Set the TimeZone in Solaris 10,11
Cannot Increase “nproc” Value More Than 1024 in CentOS/RHEL 6
The Problem "/etc/security/limits.conf" is updated with the following and the server is rebooted: # vi /etc/security/limits.conf * - nproc 16384 However, "ulimit -a" (for root & all users) still shows the 1024 for "max user processes" instead of 16384: # ulimit -a ... max user processes (-u) 1024 ... The Solution CentOS/RHEL 6 has another file for setting the nproc value - /etc/security/limits.d/90-nproc.conf # cat /etc/security/limits.d/90-nproc.conf * soft … [Read more...] about Cannot Increase “nproc” Value More Than 1024 in CentOS/RHEL 6
How to Execute Scripts/Commands using /etc/rc.d/rc.local in CentOS/RHEL 7
The Problem The scripts/commands in the configuration file /etc/rc.d/rc.local could not work at boot time in a CentOS/RHEL 7 system. Same used to work in earlier CentOS/RHEL versions. Is it depricated or is there a workaround to still use this method? The Answer The rc.local service is stopped by default in CentOS/RHEL 7. If you check the etc/rc.d/rc.local configuration file, there are hints about this. # cat /etc/rc.d/rc.local #!/bin/bash # THIS FILE IS ADDED FOR COMPATIBILITY … [Read more...] about How to Execute Scripts/Commands using /etc/rc.d/rc.local in CentOS/RHEL 7
Unable to Run X Applications Through SSH in Linux
The Problem The user is unable to run X applications through SSH on a CentOS/RHEL system. The following message is displayed: # xclock Error: Can't open display: The Solution 1. X11 forwarding is disabled on SSH login unless "-X" option is specified: # ssh -X user@address 2. It may have been disabled in "/etc/ssh/sshd_config" with the below setting: # vi /etc/ssh/sshd_config ... X11Forwarding no ... 3. Please make sure X11 forwarding is enabled in "/etc/ssh/sshd_config": # vi … [Read more...] about Unable to Run X Applications Through SSH in Linux
How to Find Number of CPU Sockets on a CentOS/RHEL System
In our company we have some 3rd-party products installed on CentOS/RHEL systems. The Application team needed to do some accounting on how each product was licensed using number of CPU sockets in the each system. Sadly they did not have any type of CMDB in place to help (Configuration Management Database - something very handy to have when it comes to looking at your server inventory). Here is a short note to get the number of CPU sockets on a CentOS/RHEL system. Determine number of CPU … [Read more...] about How to Find Number of CPU Sockets on a CentOS/RHEL System
How to Check Solaris Release and Default Kernel Version
How to Determine the Installed Solaris OS Release The most reliable method for determining the release of the Solaris OS installed is through the contents of the /etc/release file. This file was first introduced in Solaris 2.5.1 HW 4/97 and is included in all subsequent versions. The various tables shown below can be used to map the contents of this file to the release of the Solaris OS installed. If the /etc/release file has been deleted from a system it is also possible up to Solaris 10 to … [Read more...] about How to Check Solaris Release and Default Kernel Version
XFS error: Unable to mount filesystem With Noacl Permission in CentOS/RHEL 7
The Problem User is unable to mount xfs with noacl permission. noactl mount option for xfs file system is set in /etc/fstab file. # cat /etc/fstab /dev/sbb1 /mnt xfs inode64.noacl 0 0 But mounting failed with error below. # mount -v /mnt mount: wrong fs type, bad option, bad superblock on /dev/mapper/vg_cdm_ebsul06_N00-appl_ptch, missing codepage or helper program, or other error In some cases useful info is found in syslog - try The dmesg errors for the noacl option … [Read more...] about XFS error: Unable to mount filesystem With Noacl Permission in CentOS/RHEL 7
How To Execute The Pstack Command On CentOS/RHEL
The pstack(1) command print a stack trace of a running process. Use the below steps to install it on a CentOS/RHEL system. What Package provides pstack Command For CentOS/RHEL 5 The pstack package can be installed with: # yum install pstack For CentOS/RHEL 6,7 In CentOS/RHEL 6/7, the pstack tool is provided by gdb package. To install gdb, please do : # yum install gdb The gdb package will include the gstack and pstack commands. For example: # rpm -ql gdb-7.2-92.el6.x86_64 | egrep … [Read more...] about How To Execute The Pstack Command On CentOS/RHEL