Useful Linux Commands

These are the commands that a Systems Administrator or a DevOps Engineer needs on a daily basis

Basic Configuration Commands

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• Set TimeZone

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dpkg-reconfigure tzdata

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• Set Hostname

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sudo hostnamectl set-hostname exampl.com 

SCP Command

Usage

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Copy a single file

scp file.txt user@remote_ip:/remote/directory

Copy a folder

scp -r /local/directory user@remote_ip:/remote/directory

Copy file between two remote servers

scp user1@remote_ip1:/files/file.txt user2@remote_ip2:/files

Copy file from a remote server

scp user@remote_ip:/remote/file.txt /local/directory

Deflate .tgz file

Usage

tar -xvzf /path/to/yourfile.tgz

where,

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• x for extract

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• v for verbose

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• z for gnuzip

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• f for file, should come at last just before file name.

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Package Manager Commands

Update APT Silently

sudo apt -qqy update

Docker Commands

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Disk Commands

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• Check Read Speeds

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sudo dd if=/dev/zero of=/dev/nvme0n1 bs=1G count=1 oflag=direct

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• Check Write Speeds

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sudo dd if=/dev/nvme0n1 of=/dev/null bs=1G count=1 iflag=direct

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• Run Long SMART Tests on SATA Drives

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sudo smartctl -t long /dev/sdX

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• Check SMART Test Results

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sudo smartctl -a -d ata /dev/sdX

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• Check NVMe Details

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First install nvme-cli

sudo apt install nvme-cli

Run nvme smart log command

sudo nvme smart-log /dev/nvme0

Run long tests on NVMe using nvme-cli

nvme device-self-test --self-test-code 2h /dev/nvme0

More info about the NVMe can be obtained using SMART

sudo smartctl --info /dev/nvme0n1