Commands

Cheat Sheet for mdadm & lvm

Posted by phatdee on December 24, 2019

Posted in: LVM, mdadm. Tagged: gpt, initramfs, lv, lvm, md0, mdadm, mirror, mkpart, parted, pv, pvcreate, raid1, sfdisk, sysctl, vg. Leave a Comment

Copied from https://gist.github.com/plepe

mdadm

md: multiple devices
command description

cat /proc/mdstat

1	cat /proc/mdstat

show status of all raids

mdadm --detail /dev/md0

1	mdadm --detail /dev/md0

detailed status of raid md0

mdadm --create /dev/md0 -n2 -l1 /dev/sda1 /dev/sdb1

1	mdadm --create /dev/md0 -n2 -l1 /dev/sda1 /dev/sdb1

new raid /dev/md0 with 2 disks, raid level 1 on /dev/sda1 and /dev/sda2

mdadm --fail /dev/md0 /dev/sda1

1	mdadm --fail /dev/md0 /dev/sda1

mdadm --remove /dev/md0 /dev/sda1

1	mdadm --remove /dev/md0 /dev/sda1

remove /dev/sda1 from /dev/md0

mdadm --add /dev/md0 /dev/sda1

1	mdadm --add /dev/md0 /dev/sda1

add /dev/sda1 to /dev/md0

mdadm --grow /dev/md0 -n3

1	mdadm --grow /dev/md0 -n3

use 3 disks in raid /dev/md0 (e.g. add an additional disk, so a damaged drive can be removed later-on)

mdadm --assemble /dev/md0

1	mdadm --assemble /dev/md0

Assemble /dev/md0 (e.g. when running live system)

mdadm --detail --scan >> /etc/mdadm/mdadm.conf

1	mdadm --detail --scan >> /etc/mdadm/mdadm.conf

Update list of arrays in /etc/mdadm/mdadm.conf ; you should remove old list by hand first!

mdadm --examine /dev/sda1

1	mdadm --examine /dev/sda1

What is this disk / partition?

sysctl -w dev.raid.speed_limit_min=10000

1	sysctl -w dev.raid.speed_limit_min=10000

Set minimum raid rebuilding speed to 10000 kiB/s (default 1000)

sfdisk -d /dev/sdX | sfdisk /dev/sdY

1	sfdisk -d /dev/sdX \| sfdisk /dev/sdY

Copy partition table from sdX to sdY (MBR only)

sgdisk /dev/sdX -R /dev/sdY ; sgdisk -G /dev/sdY

1	sgdisk /dev/sdX -R /dev/sdY ; sgdisk -G /dev/sdY

Copy partition table from sdX to sdY (GPT)

To boot a machine even with a degraded array, modify /etc/initramfs-tools/conf.d/mdadm and run update-initramfs -c -kall (Use with caution!)

LVM

pv: physical device (e.g. /dev/md0 or /dev/sda1)
vg: volume group (consists of 1 or more pvs, contains lvs); has a name (e.g. lvm)
lv: logical volume (has a name which defines its path, e.g. /dev/lvm/root which equals dev/mapper/lvm-root)
command description

pvcreate /dev/md0

1	pvcreate /dev/md0

initializes /dev/md0 as phys device for a volume group

vgcreate lvm /dev/md0

1	vgcreate lvm /dev/md0

create volume group lvm with phys device /dev/md0

lvcreate -L30G -nroot lvm ; mkfs.ext4 /dev/lvm/root

1	lvcreate -L30G -nroot lvm ; mkfs.ext4 /dev/lvm/root

create logical volume root, sized 30G in volume group lvm; format with ext4

lvextend -L60G -nroot lvm ; resize2fs /dev/lvm/root

1	lvextend -L60G -nroot lvm ; resize2fs /dev/lvm/root

extend /dev/lvm/root to 60G; also resize file system to new size

pvs, vgs, lvs

1	pvs, vgs, lvs

show short info about pv, vg and lv

pvdisplay, vgdisplay, lvdisplay

1	pvdisplay, vgdisplay, lvdisplay

show long info

pvscan /dev/md0

1	pvscan /dev/md0

scan disks for physical volumes (e.g. when running live system)

vgextend lvm /dev/md1

1	vgextend lvm /dev/md1

add phys device /dev/md1 to volume group lvm (need pvcreate first!)

pvmove /dev/md0 ; vgreduce lvm /dev/md0

1	pvmove /dev/md0 ; vgreduce lvm /dev/md0

move all logical volumes from /dev/md0 and remove phys device from volume group

Other
create bios grub partition

parted
mklabel gpt
unit s
mkpart bios 64s 2047s
set 1 bios_grub on
mkpart NAME 2048s [end]

parted

mklabel gpt

unit s

mkpart bios 64s 2047s

set 1 bios_grub on

mkpart NAME 2048s [end]

Nmap Command Examples

Posted by phatdee on June 4, 2019

Posted in: Nmap. Tagged: nmap. Leave a Comment

This is really old, but still helpful

Basic scan:

$ sudo nmap 192.168.1.50

1

$ sudo nmap 192.168.1.50
Scan multiple addresses:

$ sudo nmap 192.168.1.50 192.168.1.51 192.168.1.52

1

$ sudo nmap 192.168.1.50 192.168.1.51 192.168.1.52
Scan entire subnet looking for valid hosts. This quick scan will also grab MAC address and perform MAC lookup to help determine what the host is.

$ sudo nmap -sP 192.168.1.50

1

$ sudo nmap -sP 192.168.1.50
Â Discovery:Â Before a scan nmap will attempt to send an ICMP echo request.Â To not send the ICMP, :

$ sudo nmap -PN 192.168.1.50

1

$ sudo nmap -PN 192.168.1.50
To do only a ping scan:

$ sudo nmap -sP 192.168.1.50

1

$ sudo nmap -sP 192.168.1.50
Do an ARP Ping scan:

$ sudo nmap -PR 192.168.1.50

1

$ sudo nmap -PR 192.168.1.50
Port Scanning options:Â Performing a Fast scan:

$ sudo nmap -F 192.168.1.50

1

$ sudo nmap -F 192.168.1.50
Scan only specific ports:

$ sudo nmap -p22 192.168.1.50

1

$ sudo nmap -p22 192.168.1.50
Scan multiple ports:

$ sudo nmap -p 22,25,53 , 80-250 192.168.1.50

1

$ sudo nmap -p 22,25,53 , 80-250 192.168.1.50
Scan ports by name (found in /etc/services)

$ sudo nmap -p snmtp,ftpÂ 192.168.1.50

1

$ sudo nmap -p snmtp,ftpÂ 192.168.1.50
Scan all ports:

$ sudo nmap -p "*" 192.168.1.50

1

$ sudo nmap -p "*" 192.168.1.50
Choose between TCP and/or UDP:

$ sudo nmap -p -T:3000-4000 192.168.1.50

1

$ sudo nmap -p -T:3000-4000 192.168.1.50
What OS is the target running?

$ sudo nmap -O 192.168.1.50

1

$ sudo nmap -O 192.168.1.50
If the OS is unknown, have nmap attempt to guess the OS

$ sudo nmap -O --osscan-guessÂ 192.168.1.50

1

$ sudo nmap -O --osscan-guessÂ 192.168.1.50
Service version detection

$ sudo nmap -sV 192.168.1.50

1

$ sudo nmap -sV 192.168.1.50

Creating a folder for each day of the year.

Posted by phatdee on May 11, 2019

Posted in: Commands, Mkdir. Tagged: day, mkdir, month, year. Leave a Comment

This will create a folder for each month 01-12.Â Inside each month folder will be 30 or 31 folders for each day of the month except for Feb. which will have only 28.Â This can be changed to 29 if it happens to be a leap-year.

mkdir -p {01,03,05,07,08,10,12}/{01..31} 02/{01..28} {04,06,09,11}/{01..30}

1	mkdir -p {01,03,05,07,08,10,12}/{01..31} 02/{01..28} {04,06,09,11}/{01..30}

Counting the number of occurrences for each word in a file.

Posted by phatdee on August 3, 2018

Posted in: Bash, Commands, Uncategorized. Tagged: bash, cat, tr, uniq. Leave a Comment

All words only.

cat file | tr -sc '[:alpha:]' '[\n*]' | sort | uniq -c |sort -nr

1	cat file \| tr -sc '[:alpha:]' '[\n*]' \| sort \| uniq -c \|sort -nr

All words and digits

cat file | tr -sc '[:alnum:]' '[\n*]' | sort | uniq -c |sort -nr

1	cat file \| tr -sc '[:alnum:]' '[\n*]' \| sort \| uniq -c \|sort -nr

Sometimes piping to less on each is helpful depending on how big your file is.

Quickly change permissions on thousands of files/directories.

Posted by phatdee on March 2, 2018

Posted in: Find. Tagged: chmod, commands, find, perms, useful commands. Leave a Comment

This is nothing new but forgot how to do it, so just updating the blog.Â Â 🙂

Change perms for directories only.

find .Â -type d -exec chmodÂ 755 {} \;

1	find .Â -type d -exec chmodÂ 755 {} \;

Change perms for files only.

find . -type f -exec chmodÂ 644 {} \;

1	find . -type f -exec chmodÂ 644 {} \;

UnixDude

"To be a warrior is not a simple matter of wishing to be one. It is rather an endless struggle that will go on to the very last moment of our lives. Nobody is born a warrior, in exactly the same way that nobody is born an average man. We make ourselves into one or the other." --Kokoro

Commands

Cheat Sheet for mdadm & lvm

Copied from https://gist.github.com/plepe

mdadm

LVM

Other
create bios grub partition

Nmap Command Examples

Creating a folder for each day of the year.

Counting the number of occurrences for each word in a file.

Quickly change permissions on thousands of files/directories.

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Copied from https://gist.github.com/plepe

mdadm

LVM

Other create bios grub partition

Categories

Archives

Spam Blocked

Recent Posts

Categories

Spam Blocked

Recent Posts

My Steam’s Game WishList

Other
create bios grub partition