ls /etc/systemd/system/*.wants/docker.service
Monthly Archives: December 2014
systemd change default runlevel
rm -rf /etc/systemd/system/default.target
ln -sf /lib/systemd/system/multi-user.target /etc/systemd/system/default.target
check current run level:
systemctl list-units –type=target
systemd set service start on boot
sudo systemctl enable service_name.service
linux add user to group
Its only example:
sudo gpasswd –add someuser docker
Adding user user to somegroup docker
update fedora 20 kde to 21
fedup –network 21 –product=nonproduct
Enable kdump
rpm -qa | grep `uname -r`
yum –enablerepo=debug install kexec-tools crash kernel-debug kernel-debuginfo-`uname -r`
vi /boot/grub/grub.conf
you should add new kernel parameter like: crashkernel=128M
chkconfig kdump on
service kdump start
Check if kdump is active: cat /sys/kernel/kexec_crash_loaded
Test kernel panic:
echo 1 > /proc/sys/kernel/sysrq
echo c > /proc/sysrq-trigger
Check log in: /var/crash
crash /usr/lib/debug/lib/modules/`uname -r`/vmlinux /var/crash/127.0.0.1-2014-12-14-16\:40\:21/vmcore
phpci
PHPCI is a free and open source continuous integration tool specifically designed for PHP. Built with simplicity in mind and featuring integrations with all of your favourite testing tools, we’ve created the very best platform for testing your PHP projects.
replace two blank lines with one
No need to use sed, just: cat -s
Unable to read /dev/sda
Its usually means HDD case or cables issues and you should check your server hardware.
ata1.00: end_request: I/O error, dev sda, sector 0
This kernel message usually means sata ghard disk drive or sata cables issues. Id you are using SSD, you should change sata cables.
kill all user proccess
kill -9 `lsof -t -u nobody`
lsof -t -u nobody get all users PIDS
ansible if then task
tasks:
- shell: if [[ -f "/etc/passwd" ]]; then /bin/true; else /bin/false; fi
register: result
ignore_errors: True
- command: /bin/something
when: result|failed
- command: /bin/something_else
when: result|success
- command: /bin/still/something_else
when: result|skipped
Zabbix monitor DISK I/O
Zabbix disk i/o template:
zbx_linux_disk_io_template.xml.tar
Auto discovery script for zabbix agents written in perl:
#!/usr/bin/perl
use strict;
use warnings;
# Options
my $_proc = “/proc/diskstats”;
# Validate options
if ( ! -e $_proc)
{
die “File $_proc not found!”;
}
# Keep count
my $_first = 1;
# Present the data in JSON format
print “{\n”;
print “\t\”data\”:[\n\n”;
# Fetch the data and put it in an array
my @_data = `cat $_proc | awk ‘{ print \$3 }’`;
chomp @_data;
# Read the array and print the wanted data
foreach my $_disk (@_data)
{
# Print the data in JSON
print “\t,\n” if not $_first;
$_first = 0;
print “\t{\n”;
print “\t\t\”{#DISK}\”:\”$_disk\”\n”;
print “\n\t}\n”;
}
print “\n\t]\n”;
print “}\n”;
Zabbix userparameter_linux_disks.conf:
# See https://www.kernel.org/doc/Documentation/ABI/testing/procfs-diskstats
#
# reads completed successfully
UserParameter=custom.vfs.dev.read.ops[*],cat /proc/diskstats | egrep $1 | head -1 | awk ‘{print $$4}’
# sectors read
UserParameter=custom.vfs.dev.read.sectors[*],cat /proc/diskstats | egrep $1 | head -1 | awk ‘{print $$6}’
# time spent reading (ms)
UserParameter=custom.vfs.dev.read.ms[*],cat /proc/diskstats | egrep $1 | head -1 | awk ‘{print $$7}’
# writes completed
UserParameter=custom.vfs.dev.write.ops[*],cat /proc/diskstats | egrep $1 | head -1 | awk ‘{print $$8}’
# sectors written
UserParameter=custom.vfs.dev.write.sectors[*],cat /proc/diskstats | egrep $1 | head -1 | awk ‘{print $$10}’
# time spent writing (ms)
UserParameter=custom.vfs.dev.write.ms[*],cat /proc/diskstats | egrep $1 | head -1 | awk ‘{print $$11}’
# I/Os currently in progress
UserParameter=custom.vfs.dev.io.active[*],cat /proc/diskstats | egrep $1 | head -1 | awk ‘{print $$12}’
# time spent doing I/Os (ms)
UserParameter=custom.vfs.dev.io.ms[*],cat /proc/diskstats | egrep $1 | head -1 | awk ‘{print $$13}’
Full article there:
http://www.denniskanbier.nl/blog/monitoring/monitoring-disk-io-using-zabbix/
Xming X Server
Xming is the leading X Window System Server for Microsoft Windows 8/7/Vista/XP (+ server 2012/2008/2003). It is fully featured, small and fast, simple to install and because it is standalone native Microsoft Windows, easily made portable.
XDMCP on Centos OS
yum install tigervnc-server xorg-x11-fonts-Type1 xinetd
vi /etc/gdm/custom.conf
[security]
AllowRemoteRoot=true
DisallowTCP=false
[xdmcp]
Enable=true
MaxSessions=30
vi /etc/xinetd.d/vncserver
service vncserver
{
disable = no
socket_type = stream
protocol = tcp
group = tty
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -geometry 1024×768 -depth 16 -once -fp /usr/share/X11/fonts/misc -securitytypes=none
}
vi /etc/services
vncserver 5900/tcp # VNC and GDM
systemctl restart xinetd.service
firewall-cmd –permanent –zone=public –add-port=5900/tcp
firewall-cmd –reload
Connect using some VNC client:
your_server_IP:5900