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GCE Agent Powershell

This is a Powershell script to restart a service if it’s down.

$ServiceName = 'GCEAgent'
$arrService = Get-Service -Name $ServiceName
 
if ($arrService.Status -ne 'Running')
{
 
    Start-Service $ServiceName
    write-host $arrService.status
    write-host 'Service starting'
    Start-Sleep -seconds 60
    $arrService.Refresh()
    if ($arrService.Status -eq 'Running')
    {
        Write-Host 'GCE Agent Service is now Running'
    }
 
}
else
{
    Write-Host 'GCE Agent Service is Running'
}

GCP Check Instances Running

Here’s how to check if instances are running in GCP. 

#!/bin/bash
while IFS=', ' read -r a b c; do
  instance="${a//[[:blank:]]/}"
  project="${b//[[:blank:]]/}"
  zone="${c//[[:blank:]]/}"
  gcloud compute instances describe $instance \
  --zone $zone --project $project \
  --format='table[no-heading](name,status,zone)'
done < instance-list.txt

Instances are read from an external file. File is comma delimited with instance name, project id and zone data.

Removing Old Kernels

How to check which kernel is running on your system

uname -sr

List all kernels installed on the system.

rpm -q kernel

Removing old kernels using package-cleanup. This keeps 2 kernels on the system.

yum install yum-utils
package-cleanup --oldkernels --count=2

RPM Check Packages

How to check RPM if packages are installed.

rpm -qa --last 
rpm -qa --last | more
rpm -qa --last | grep "package name"

Check Memory in Linux

Here are several commands to check memory in Linux.

free -m
cat /proc/meminfo
vmstat -s
top

Check Argument in Bash

How to check for an argument in a script in Bash.

if [ -z "$1" ] ; then
  echo "there are no arguments"
else
  echo "there is an argument"
fi