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% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
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% Document Info
\author{James Draper (drapja)}
\pdfinfo{
  /Title (linux-raid-with-mdadm.pdf)
  /Creator (Cheatography)
  /Author (James Draper (drapja))
  /Subject (Linux RAID with mdadm Cheat Sheet)
}

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\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
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    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
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\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Linux RAID with mdadm Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{James Draper (drapja)} via \textcolor{DarkBackground}{\uline{cheatography.com/33530/cs/17725/}}}
\end{tabulary}
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\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}James Draper (drapja) \\
  \uline{cheatography.com/drapja} \\
        \uline{\seqsplit{jamesdraper}.me}
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
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  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Published 31st October, 2018.\\
   Updated 1st November, 2018.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
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  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
  \SetRowColor{white}
  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

% Set font size to small. Switch to any value
% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.

\begin{multicols*}{2}

\begin{tabularx}{8.4cm}{p{1.04 cm} x{6.96 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{8.4cm}}{\bf\textcolor{white}{RAID Levels}}  \tn
% Row 0
\SetRowColor{LightBackground}
RAID 0 & {\bf{Stripes}} data evenly across two or more disks. \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
RAID 1 & {\bf{Mirrors}} data on two or more disks. \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
RAID 2 & Rarely used, Bit-level striping with Hamming code for error correction. \tn 
% Row Count 7 (+ 3)
% Row 3
\SetRowColor{white}
RAID 3 & Rarely used, byte-level striping with a dedicated parity. \tn 
% Row Count 9 (+ 2)
% Row 4
\SetRowColor{LightBackground}
RAID 4 & Block-level striping with {\bf{dedicated parity}}. \tn 
% Row Count 11 (+ 2)
% Row 5
\SetRowColor{white}
RAID 5 & Block-level striping with {\bf{distributed parity}}. \tn 
% Row Count 13 (+ 2)
% Row 6
\SetRowColor{LightBackground}
RAID 6 & Block-level striping with {\bf{double distributed parity}}. \tn 
% Row Count 15 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{x{0.988 cm} x{4.104 cm} x{2.508 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{3}{x{8.4cm}}{\bf\textcolor{white}{Nested RAID Levels}}  \tn
% Row 0
\SetRowColor{LightBackground}
{\bf{Number}} & {\bf{Description}} & \{\{nobreak\}\}{\bf{Efficiency}} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
RAID 01 & Block-level striping, and mirroring without parity & 1/stripes \tn 
% Row Count 5 (+ 3)
% Row 2
\SetRowColor{LightBackground}
RAID 10 & Mirroring without parity, and block-level striping & stripes/n \tn 
% Row Count 8 (+ 3)
% Row 3
\SetRowColor{white}
RAID 50 & Block-level striping with distributed parity, and block-level striping & \seqsplit{(1-stripes)/n} \tn 
% Row Count 12 (+ 4)
% Row 4
\SetRowColor{LightBackground}
RAID 60 & Block-level striping with double distributed parity, and block-level striping & \seqsplit{(1-2*stripes)/n} \tn 
% Row Count 16 (+ 4)
\hhline{>{\arrayrulecolor{DarkBackground}}---}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Formatting Disks for Use with mdadm}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{DISCLAIMER: PROCEED WITH CAUTION.}}} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{MAKE SURE YOU KNOW WHAT DISK YOU ARE OPERATING ON. IT IS VERY EASY TO DO IRREVOCABLE DAMAGE TO YOUR SYSTEM IF YOU DON'T.} \tn 
% Row Count 4 (+ 3)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{0. Figure out disk location in the file system:}}} \tn 
% Row Count 6 (+ 2)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`lsblk -o name,size,fstype,type,mountpoint`} \tn 
% Row Count 7 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{1. Formatting with fdisk}}} \tn 
% Row Count 8 (+ 1)
% Row 5
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`sudo fdisk /dev/sdx`} \tn 
% Row Count 9 (+ 1)
% Row 6
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{2. Navigatng fdisk: just press the following keys when promted to create new linux RAID type primary partition }}} \tn 
% Row Count 12 (+ 3)
% Row 7
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`n`, `p`, `1`, `Enter`, `Enter`, `t`, `fd`, `w`} \tn 
% Row Count 13 (+ 1)
% Row 8
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{3. Repeat steps 1 and 2 for each disk that will be included in new array}}} \tn 
% Row Count 15 (+ 2)
% Row 9
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`sudo fdisk /dev/sdy`} \tn 
% Row Count 16 (+ 1)
% Row 10
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{`n`, `p`, `1`, `Enter`, `Enter`, `t`, `fd`, `w`} \tn 
% Row Count 17 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Creating RAID arrays}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{Create a mirrored array}}} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{mdadm -{}-create /dev/md0 -{}-level=1 /dev/sdx1 /dev/sdy1} \tn 
% Row Count 3 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Assembling RAID arrays}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{Assemble an existing array}}} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{\{\{nobreak\}\}`mdadm -{}-assemble /dev/md0 /dev/sdx1 /dev/sdy1`} \tn 
% Row Count 3 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{\{\{nobreak\}\}`mdadm -{}-scan -{}-assemble -{}-uuid=\textless{}UUID\textgreater{}`} \tn 
% Row Count 4 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Resetting Existing RAID Devices}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{Find the active arrays}}} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`cat /proc/mdstat`} \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{Unmount the array}}} \tn 
% Row Count 3 (+ 1)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`sudo umount /dev/md0`} \tn 
% Row Count 4 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{Stop and remove the array}}} \tn 
% Row Count 5 (+ 1)
% Row 5
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`mdadm -{}-stop /dev/md0`} \tn 
% Row Count 6 (+ 1)
% Row 6
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{`mdadm -{}-remove /dev/md0`} \tn 
% Row Count 7 (+ 1)
% Row 7
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{{\bf{Find the devices used to build the array }}} \tn 
% Row Count 8 (+ 1)
% Row 8
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{`lsblk -o name,fstype,mountpoint`} \tn 
% Row Count 9 (+ 1)
% Row 9
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{{\bf{Zero out the respective superblocks}}} \tn 
% Row Count 10 (+ 1)
% Row 10
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{`sudo mdadm -{}-zero-superblock /dev/sdx`} \tn 
% Row Count 11 (+ 1)
% Row 11
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`sudo mdadm -{}-zero-superblock /dev/sdy`} \tn 
% Row Count 12 (+ 1)
% Row 12
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{Remove persistent references to the array}}} \tn 
% Row Count 13 (+ 1)
% Row 13
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`sudo nano /etc/fstab`} \tn 
% Row Count 14 (+ 1)
% Row 14
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{Comment out or remove the reference to the array.} \tn 
% Row Count 15 (+ 1)
% Row 15
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{\{\{nobreak\}\}`\# /dev/md0 /mnt/md0 ext4 defaults,nofail,discard 0 0`} \tn 
% Row Count 17 (+ 2)
% Row 16
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{In `/etc/mdadm/mdadm.conf` comment out or remove the array reference} \tn 
% Row Count 19 (+ 2)
% Row 17
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`sudo nano /etc/mdadm/mdadm.conf`} \tn 
% Row Count 20 (+ 1)
% Row 18
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{Comment out the reference} \tn 
% Row Count 21 (+ 1)
% Row 19
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`\# ARRAY /dev/md0 metadata=1.2 name=mdadmwrite:0 UUID=xxxx`} \tn 
% Row Count 23 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Citations}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{\seqsplit{https://en.wikipedia.org/wiki/Standard\_RAID\_levels} \newline % Row Count 2 (+ 2)
\seqsplit{https://en.wikipedia.org/wiki/Nested\_RAID\_levels} \newline % Row Count 3 (+ 1)
\seqsplit{https://www.digitalocean.com/community/tutorials/an-introduction-to-raid-terminology-and-concepts} \newline % Row Count 5 (+ 2)
\seqsplit{https://www.digitalocean.com/community/tutorials/how-to-manage-raid-arrays-with-mdadm-on-ubuntu-16-04}% Row Count 8 (+ 3)
} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}