Occasionally as a Linux administrator you will be in the situation where working on a remote server and you are left with no option but to force a reboot the system. This may be for a number of reasons, but where I have found it most frequent is when working on Linux clusters in a remote location.
When the "reboot" or "shutdown" commands are executed daemons are gracefully stopped and storage volumes unmounted.
This is usually accomplished via scripts in the /etc/init.d directory which will wait for each daemon to shut down gracefully before proceeding on to the next one. This is where a situation can develop where your Linux server fails to shutdown cleanly leaving you unable to administer the system until it is inspected locally. This is obviously not ideal so the answer is to force a reboot on the system where you can guarantee that the system will power cycle and come back up. The method will not unmount file systems nor sync delayed disk writes, so use this at your own discretion.
To force the kernel to reboot the system we will be making use of the magic SysRq key.
The magic_SysRq_key provides a means to send low level instructions directly to the kernel via the /proc virtual file system.
To enable the use of the magic SysRq option type the following at the command prompt:
echo 1 > /proc/sys/kernel/sysrq
Then to reboot the machine simply enter the following:
echo b > /proc/sysrq-trigger
Voilà! Your system will instantly reboot.
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All temporary files created by Recital are stored in the directory specified by the environment variable DB_TMPDIR.
mkdir /opt/recital/tmp
mount -t tmpfs -o size=1g recitaltmpfs /usr/recital/tmp
The goal of the SCPlugin project is to integrate Subversion into the Mac OS X Finder.
- Support for Subversion.
- Access to commonly used source control operations via contextual menu [screenshot]
- Dynamic icon badging for files under version control. Shows the status of your files visually. [ screenshot ]
If you have 4 GB or more RAM use the Linux kernel compiled for PAE capable machines. Your machine may not show up total 4GB ram. All you have to do is install PAE kernel package.
This package includes a version of the Linux kernel with support for up to 64GB of high memory. It requires a CPU with Physical Address Extensions (PAE).
The non-PAE kernel can only address up to 4GB of memory. Install the kernel-PAE package if your machine has more than 4GB of memory (>=4GB).
# yum install kernel-PAE
If you want to know how much memory centos is using type this in a terminal:
# cat /proc/meminfo
RTOS()
Syntax
RTOS( [ <workarea> ] )Description
The RTOS() function returns all the fields in the current row as a string. The string will begin with the unique row identifier and then the deleted flag, followed by the data in the record. An optional workarea can be specified, otherwise the current workarea will be usedExample
use backup in 0
use accounts in 0
nrecs=reccount()
for i = 1 to nrecs
if rtos(accounts) != rtos(backup)
debug("record "+recno()+" don't match")
endif
next
If you are using the Oracle Gateway in Recital, make sure the Oracle environment (ORACLE_HOME, ORACLE_SID etc.) is set up before starting the Recital Server. If not, you will see the error ORA-01019. A call to the Oracle environment setup script can be added to the /etc/init.d/recital script if your Recital Server is set to run on startup.
lslk lists information about locks held on files with local inodes on systems running linux.
Install it with:
yum install lslk