NOHUP Running the long running commands in background



This article will guide you through how to run the long running command in background without hanging, see the job status and get the output to the file for diagnostic purpose.

We can use nohup and send your long running command to background so that you can continue while the command will keep on executing in the background. After that you can safely log out.

With nohup command we tell the process to ignore the SIGHUP signal which is sent by command on termination, thus making the command persist even after session logout. On session logout the command is detached from the controlling terminal and keeps on running in the background as the daemon process.

Executing command using nohup in the background

Here, is a simple scenario wherein, I am trying to restore a big database file in the background on ssh session using nohup, after which the task was sent to background with prompt returning immediately giving PID and job ID of the process ([JOB-ID] P-ID).

# nohup mysql -uroot -p testdatabasesql.sql < backup.sql &
nohup: ignoring input and appending output to `nohup.out'


To See the list of jobs running in background

# jobs

Resuming the session to view if job is still running

When you re-login again, you can check the status of the command, bring it back to foreground using

# fg %JOB-ID or fg 

To monitor its progress and so on. Below, the output shows that the job was completed as it doesn’t show on re-login, and has given the output which is displayed.

# fg %JOBID

To see the result or any error for restoring the database 

# cat nohup.out


Please give your valuable comments and also share

Keywords: Run command in background, nohup, long run commands

Comments

Post a Comment

Popular posts from this blog

Observium: Configuring Microsoft Windows 2008 Server SNMP Agent

Image
1 . Open Control Pannel. 2. Right click on “ Programs & Features ” and click on “ Turn Windows Features on or off" 3 . Expand “ SNMP Services ” and select “ SNMP Service ” click Next 4. Click Install 5. Close  Programs & Features ” 6. Open Ädministraive Tools and clicket Services 7. Expand Configuration and select Services,  Select SNMP Service , right click and select properties 8 . Select the “ Agent ” tab 9. Type the contact name responsible for this server or email address 10 . Type the location eg, Hyderabad,India. 11 . Tick the following  Physical Datalink and subnetwork  SNMP Trap Service - Agent 12 . Select the “ Traps ” tab 13 . Type in the community string you are using in your environment and select “ Add to list ” 14 . Click “ Add ” 15 . Type the IP of the Observium ServerSNMP Trap Service - Traps 16 . Select “ Security ” tab 17 . Ensure “ Send ...
Read more

AWS: Introduction to AWS (Amazon Web Services)

Image
Amazon Web Services (AWS) Considering that you don't have an account with AWS ( Amazon Web Services) this Demo is divided into 5 steps 1. Creating/Sign Up for AWS account. 2. Creat ing an IAM user . 3. Creat ing a secure key pair. 4. Creat ing a Virtual Private Cloud (VPC) 5. Creat ing a security group for access. 1. Creating/Sign Up for AWS account When we sign up for the AWS account, we get automatic  access for all the services in the AWS, which includes the Amazon EC2 and we are charged for only the services which we chose and use. With Amazon EC2 we will pay for that what we use and if we are a  new AWS customer and we can get started with Amazon EC2 for free. If we have an AWS account already, we can skip the next task or else we can continue with the account creation. You can check the AWS Free Tier information here http://aws.amazon.com/free/ To create an AWS account, we needed to access the URL a). Connect to the URL ht...
Read more

System/Server Health Status using PowerShell

Image
System/Server Health Status using PowerShell Support team or System Administrators who are willing to get the system health check status can use this script. This script has been written in Powershell and it can generate   reports   in HTML format. This script can give you below information: Hardware: To Get Manufacturer, Model, No.   Of   Logical Processors, Installed Memory.   Code:  Get-WmiObject -class Win32_ComputerSystem -ComputerName $Computername | Select-Object Name,Domain,Manufacturer, Model,NumberOfLogicalProcessors,@{ Name = "Installed Memory (GB)" ; Expression = { "{0:N0}" -f( $_.TotalPhysicalMemory / 1gb ) } }            CPU Details: To Get  CPU speed, Current CPU Usage in %,  Code: Get-WmiObject win32_processor | Select-Object SystemName,@{ Expression = { $_.MaxClockSpeed...
Read more