edgecase
datafeed article 19
published: 2017-11-15
author: stjohn_piano
signed by author: yes




Note: The CentOS-6.9-x86_64-LiveDVD.iso file mentioned in this article is not included as an asset.


My work machine: 2008 Apple MacBook running Mac OS X 10.6.8 Snow Leopard


I want to make a bootable Centos 6.9 USB memory stick that I can use to test whether Centos 6.9 will work on my new computer Kalkin.


On wiki.centos.org/Download, I find two architectures listed for Centos 6.9 ISO images:
- i386
- x86_64


Google "i386 vs x86_64".


Q:

What is the difference between x86_64 and i386?

What is the difference? Under what category does my system fall into? I want to download Fedora12 and it shows me these options. Which one should I download?

I have a Sony Vaio cr36g/b with an Intel Core 2 Duo 8100 processor.

asked Nov 23 '09 at 17:28
pineapple

edited Nov 16 '15 at 19:44
Jamal


A:

x86_64 is for 64 bit processors. i386 is for 32 bit processors.

All Core 2 Duos are capable of running 64 bit operating systems and 32 bit operating systems.

You want x86_64 as it will run better and allow you to have more RAM in the future, although if you are worried about compatibility, you could use i386. Personally I haven't had any problems with x86_64 on Linux.

answered Nov 23 '09 at 17:36
Macha


Source:
superuser.com/questions/74351/what-is-the-difference-between-x86-64-and-i386


Key phrase: "x86_64 is for 64 bit processors. i386 is for 32 bit processors."


I need to know which architecture (64-bit or 32-bit) my processor has.


Processor (CPU): Intel Xeon E3-1230 Quad Core 3.20GHz - 8MB Smart Cache - 3.60GHz Turbo Boost


Source:
Edgecase Datafeed / article 17 / New computer: Kalkin


Google "Xeon E3-1230".


Intel® Xeon® Processor E3-1230
8M Cache, 3.20 GHz

[...]

Intel® 64: Yes
Instruction Set: 64-bit
Instruction Set Extensions: SSE4.1/4.2, AVX

[Click question mark next to "Intel 64":] Intel® 64 architecture delivers 64-bit computing on server, workstation, desktop and mobile platforms when combined with supporting software. Intel 64 architecture improves performance by allowing systems to address more than 4 GB of both virtual and physical memory.

[Click question mark next to "Instruction Set":] An instruction set refers to the basic set of commands and instructions that a microprocessor understands and can carry out. The value shown represents which Intel's instruction set this processor is compatible with.

[Click question mark next to "Instruction Set Extensions":] Instruction Set Extensions are additional instructions which can increase performance when the same operations are performed on multiple data objects. These can include SSE (Streaming SIMD Extensions) and AVX (Advanced Vector Extensions).


Source:
ark.intel.com/products/52271/Intel-Xeon-Processor-E3-1230-8M-Cache-3_20-GHz


So it's 64-bit. I'll download the x86_64 version of Centos 6.9.


Make a directory for this project. In my case, it's called
centos_6_9_bootable_usb_stick.



Variety of ISO images

Aside from the normal DVD and CD ISO images, the CentOS project occasionally releases special ISO images. Not all point releases get fresh spins of what is substantially unchanging content; if the latest and greatest refresh point spin does not have what you seek, you may wish to use the last version seen for a LiveCD or ServerCD, and as appropriate run updates in a post-install process:

- LiveCD - Bootable CD image with a working environment directly from CD
- ServerCD - Installable CD image with a limited package-set for server installations
- netinstall - Minimal CD image to start network installations (<10M)

The netinstall iso will only work with the corresponding point release, eg one cannot use the netinstall from CentOS Linux 6.2 to install CentOS Linux 6.3.


Source:
wiki.centos.org/Download


On wiki.centos.org/Download, click Base Distribution / Centos 6 / x86_64
[direct link]

Click mirror:
www.mirrorservice.org/sites/mirror.centos.org/6.9/isos/x86_64


Files listed:
- 0_README.txt
- CentOS-6.9-x86_64-LiveDVD.iso
- CentOS-6.9-x86_64-LiveDVD.torrent
- CentOS-6.9-x86_64-bin-DVD1.iso
- CentOS-6.9-x86_64-bin-DVD1to2.torrent
- CentOS-6.9-x86_64-bin-DVD2.iso
- CentOS-6.9-x86_64-minimal.iso
- CentOS-6.9-x86_64-minimal.torrent
- CentOS-6.9-x86_64-netinstall.iso
- CentOS-6.9-x86_64-netinstall.torrent
- md5sum.txt
- md5sum.txt.asc
- sha1sum.txt
- sha1sum.txt.asc
- sha256sum.txt
- sha256sum.txt.asc


Right-click 0_README.txt and choose "Save Link As ...".
Save it to the project directory centos_6_9_bootable_usb_stick.

Open a terminal and change directory to the project directory centos_6_9_bootable_usb_stick.

aineko:centos_6_9_bootable_usb_stick stjohnpiano$ ls

0_README.txt


aineko:centos_6_9_bootable_usb_stick stjohnpiano$ cat 0_README.txt


What images are in this directory

CentOS-6.9-x86_64-netinstall.iso
This is the network install and rescue image.
This image is designed to be burned onto a CD. You then boot your computer off the CD.

CentOS-6.9-x86_64-minimal.iso
The aim of this image is to install a very basic CentOS 6.9 system, with the minimum of packages needed to have a functional system.
Please burn this image onto a CD and boot your computer off it. A preselected set of packages will be installed on your system. Everything else needs to be installed using yum.
The set of packages installed by this image is identical to the one installed when choosing the group named "Minimal" from the full DVD image.

CentOS-6.9-x86_64-bin-DVD1.iso
CentOS-6.9-x86_64-bin-DVD2.iso
These two dvd images contain the entire base distribution.
Please burn DVD1 onto a DVD and boot your computer off it.
A basic install will not need DVD2.
After the installation is complete, please run "yum update" in order to update your system.

CentOS-6.9-x86_64-LiveDVD.iso
This is a DVD live image of CentOS 6.9 designed to be burned onto a DVD. You then boot your computer using that DVD.
Please read http://wiki.centos.org/Manuals/ReleaseNotes/CentOSLiveDVD6.9 for more details about this image.
The disk can also be used to install CentOS 6.9 onto your computer but without offering any package selection options at install time.


Remember that in order to be able to partition your disk you will need to run the GUI installer which in turns needs enough RAM. The same is true for the network setup step.
The release notes ( http://wiki.centos.org/Manuals/ReleaseNotes/CentOS6.9 ) provide more details about these aspects.





4. Features

The primary purpose of the LiveDVD is to test out CentOS without installing it on your computer. If you already know you are going to install CentOS on your computer, the DVD1 (not LiveDVD) and netinstall images are better suited for this purpose, because they allow you to select which packages you want to install.

The LiveDVD contains a few utilities such as a web browser, document viewer, email client, image editor and word processor. GNOME is used as the desktop environment.

Once booted, the LiveDVD can also be installed to hard disk by selecting the Install to hard drive icon from the desktop. The installed system's packages will be identical to what you see when running the LiveDVD. You can naturally use yum to add/remove packages after installation.


5. Known Issues

- The size of the overlay is still limited to 4096 MB on the official Centos Live media
- LiveDVD does not boot properly on UEFI systems, giving only a grub> prompt. The other images do not have this problem.
- Even though you can also select KDE when logging in, there is no possibility to install to hard drive from within KDE. The Install to hard drive option is only available when using the default GNOME desktop environment.
- Setting the hostname might not work during installation. You may need to set the hostname after you have booted into the installed system.


Source:
wiki.centos.org/Manuals/ReleaseNotes/CentOSLiveDVD6.9


How to use ISO image files?

An ISO image file is a snapshot of the data and layout of a CD or DVD, saved in ISO-9660 format. ISO image files are widely used for storing CD content. ISO is a common CD image format for DOS, Windows (Joliet ISO extension), Linux (RockRidge ISO extension), and other operating systems.

The most common use of an image file is to write it to a blank CD-R or DVD-R, resulting in an identical copy of the original disc including file name and volume label information. ISO image files may also be opened and their contents copied to a local folder, much like ZIP files. ISO files may also be virtually mounted and accessed as a device.


Source:
www.ntfs.com/bootdisk_quest_isofiles.htm




Save CentOS-6.9-x86_64-LiveDVD.torrent to the project directory.

Use uTorrent (Version 1.8.1 (28758)) to open the torrent file and begin download.

uTorrent's default download destination is my Downloads directory. The result of the download is a directory called CentOS-6.9-x86_64-LiveDVD, containing:
- 0_README.txt
- CentOS-6.9-x86_64-LiveDVD.iso
- md5sums.txt
- md5sums.txt.asc
- README.txt
- sha1sums.txt
- sha1sums.txt.asc
- sha256sums.txt
- sha256sums.txt.asc


Once download is complete, move the directory CentOS-6.9-x86_64-LiveDVD to the project directory centos_6_9_bootable_usb_stick.


Right-click CentOS-6.9-x86_64-LiveDVD.iso and choose Get Info:
Size: 2.02 GB on disk (2,023,751,680 bytes)


wiki.centos.org/Download
links to
wiki.centos.org/TipsAndTricks/sha256sum.


Validating the Files

Errors can occur during the download of CentOS ISOs, even if your download manager reports none. Therefore it is very important to check that the files have not been corrupted in any way. This is the purpose of the CHECKSUM files (md5sum.txt.asc, sha1sum.txt.asc, sha256sum.txt.asc) we include in the iso directory. They contain one line for each of the available ISO files with a content verification code, called a hash, computed from the original ISO files.

We include 3 files (md5sum.txt, sha1sum.txt, sha256sum.txt) and their gpg clear-signed copies (md5sum.txt.asc, sha1sum.txt.asc, sha256sum.txt.asc) copies that contain the hashes for different tools. We recommend that you use the sha256.txt.asc values if you can find an sha256sum tool for your environment.

If you wish to verify the clear text signature of the signed (.asc) files, see these detailed [http://wiki.centos.org/Download/Verify] instructions

[...]


On Linux

Go to the directory where you downloaded the ISO in a command prompt and type:

sha256sum <name>.iso


Where <name> is the specific ISO you downloaded. For example in CentOS 6.5, for the minimal iso, it would be:

[jhughes@jhughes x86_64]$ sha256sum CentOS-6.5-x86_64-minimal.iso

f9d84907d77df62017944cb23cab66305e94ee6ae6c1126415b81cc5e999bdd0 CentOS-6.5-x86_64-minimal.iso


You would compare the hash received, in this case f9d84907d77df62017944cb23cab66305e94ee6ae6c1126415b81cc5e999bdd0, with the value in the file sha256sum.txt.asc. If it matches for CentOS-6.5-x86_64-minimal.iso, your iso download is good.

[...]


On Mac OS X

To check the files, download the program HashTab [http://beeblebrox.org]. Drag each CentOS image file that you want to validate, and drop it onto HashTab. Take note of the SHA256 value that HashTab displays.

Open the file sha256sum.txt.asc with a text editor, such as TextEdit, to display its contents. Make sure the hash displayed by HashTab for each of the downloaded ISO files exactly matches the corresponding hash in the sha256sum.txt.asc file.

To validate the files from the command line, use the shasum command. In order to correctly validate the files, the 256-bit algorithm must be specified. Change into the directory that holds the ISO image files, then run shasum. For example:

cd Desktop
shasum -a 256 CentOS-6.5-x86_64-minimal.iso


If all of the hashes match, you can burn the ISO file to disc. If a file does not match, download it again.


TipsAndTricks/sha256sum (last edited 2016-07-28 09:28:52 by JohnnyHughes)


Source:
wiki.centos.org/TipsAndTricks/sha256sum


wiki.centos.org/TipsAndTricks/sha256sum
links to
wiki.centos.org/Download/Verify.


How to Verify you are Getting CentOS Linux Images, ISOs, or Packages


ISO or Install Image Directories

If you can't find the specific release announcement for the ISO you have downloaded, the directory from which the ISO came will have a sha256sum.txt.asc file that you can use to verify the ISO. This procedure is a bit more complicated and we will go thru how to verify all parts of the process here. The provided sha256sum.txt.asc file is signed with the same key that the specific distribution uses for it's signed packages. I will go through the whole process for CentOS-7 and then explain the slight differences for other versions of CentOS. This procedure requires the linux gnupg package > 1.4 installed.


1. Verify the key used to sign the files

First create a validate directory (from the command line) with these commands:

mkdir validate

cd validate



The next thing to do is to verify the KEY used to sign the sha256sum file. You can find a list of keys and fingerprints here [http://www.centos.org/keys]. In this example we will verify the CentOS-7 key .. it's name is RPM-GPG-KEY-CentOS-7.


On a CentOS-7 Machine

If you are testing on a CentOS-7 machine, this key is already installed at /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7. If you are on a CentOS-7 machine, you would verify the key with this command:

gpg --quiet --with-fingerprint /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7


The output would be this:

pub 4096R/F4A80EB5 2014-06-23 CentOS-7 Key (CentOS 7 Official Signing Key) <security@centos.org>
Key fingerprint = 6341 AB27 53D7 8A78 A7C2 7BB1 24C6 A8A7 F4A8 0EB5


If the fingerprint matches the one from this list [http://www.centos.org/keys] for the CentOS 7 Signing Key, you have the right key installed on your system.


Not on a CentOS 7 Machine

If you are not on a CentOS-7 system, but another version of Linux with at least gnupg 1.4, then you need to download the public part of the signing key, in this case the CentOS-7 key.

Now download a copy of the public key:

wget http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-7


Please note that even though this is not an https location, we will verify the fingerprint of key, so you know it is correct no matter where it came from

Now, we will check the key:

gpg --quiet --with-fingerprint ./RPM-GPG-KEY-CentOS-7


The output will be:

pub 4096R/F4A80EB5 2014-06-23 CentOS-7 Key (CentOS 7 Official Signing Key) <security@centos.org>
Key fingerprint = 6341 AB27 53D7 8A78 A7C2 7BB1 24C6 A8A7 F4A8 0EB5


If the fingerprint matches the one from this list [http://www.centos.org/keys] for the CentOS 7 Signing Key, you have downloaded the right key.


2. Import the Key

We now need to import the key into our keyring. We are working with either /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 or ./RPM-GPG-KEY-CentOS-7.

gpg --import /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7


OR

gpg --import ./RPM-GPG-KEY-CentOS-7


Please note, you only have to do this step one time to get the key into your local keyring.


3. Download the ISO (or Image) file and the sha256sum.txt.asc files to validate

Once we know we have the valid public key to check the signed files, the next step of the process is to verify that the sha256sum files you want to use are valid. If you were getting the ISO file from here:

wget http://ftp.osuosl.org/pub/centos/7/isos/x86_64/CentOS-7-x86_64-DVD-1511.iso


Then once you got the ISO, you would also get the sha256sum.txt.asc file from the same place. In this particular case, from the following locations.

wget http://ftp.osuosl.org/pub/centos/7/isos/x86_64/sha256sum.txt.asc


Once you have the sha256sum.txt.asc file, you would verify it like this:

gpg --verify ./sha256sum.txt.asc


The output will look something like this:

gpg: Signature made Thu 10 Dec 2015 09:41:44 AM CST using RSA key ID F4A80EB5
gpg: Good signature from "CentOS-7 Key (CentOS 7 Official Signing Key) <security@centos.org>"
gpg: WARNING: This key is not certified with a trusted signature!
gpg: There is no indication that the signature belongs to the owner.
Primary key fingerprint: 6341 AB27 53D7 8A78 A7C2 7BB1 24C6 A8A7 F4A8 0EB5


Please verify the Primary key fingerprint listed is the correct one from this list [http://www.centos.org/keys] (we did that above, you can do it again if you prefer)

Once you have verified the signature of the sha256sum.txt.asc file, please make sure you have the ISO (or image file) and the sha256sum.txt.asc file in the same directory. You can then verify the ISO or image file with the following command:

sha256sum -c sha256sum.txt.asc 2>&1 | grep OK


The output in this example is:

CentOS-7-x86_64-DVD-1511.iso: OK



4. Other Locations

The only real difference for CentOS 6 ISOs is that the name of the key would be: RPM-GPG-KEY-CentOS-6

You would still use the sha256sum.txt.asc file from the directory where your ISO is located and still import the key once you verified it's Fingerprint.

If you are instead trying to verify a CentOS image from this directory:

CentOS 7 Cloud Images Steps [http://cloud.centos.org/centos/7/images] still the same, use the sha256sum.txt.asc file from the directory where your ISO is located and still import the key (in this case, RPM-GPG-KEY-CentOS-7 for those cloud images) once you verified it's Fingerprint.

So the basic steps are

- Verify a Key
- Import that key
- grab the image or iso file
- grab the sha256sum.txt.asc file from the same directory as the iso or image file
- verify the sha256sum.txt.asc signature
- verify the iso or image from the sha256sum.txt.asc file

With those steps, you can always verify that your ISO or image is the one released by the CentOS Linux team. You can do this no matter where you got the public key or the image/iso file .. as it relies on gpg key signing.


Source:
wiki.centos.org/Download/Verify



aineko:centos_6_9_bootable_usb_stick stjohnpiano$ gpg --version

gpg (GnuPG) 1.4.21
Copyright (C) 2015 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: ~/.gnupg
Supported algorithms:
Pubkey: RSA, RSA-E, RSA-S, ELG-E, DSA
Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
CAMELLIA128, CAMELLIA192, CAMELLIA256
Hash: MD5, SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Compression: Uncompressed, ZIP, ZLIB, BZIP2

aineko:centos_6_9_bootable_usb_stick stjohnpiano$ ls -1

0_README.txt
CentOS-6.9-x86_64-LiveDVD
CentOS-6.9-x86_64-LiveDVD.torrent

aineko:centos_6_9_bootable_usb_stick stjohnpiano$ ls -1 CentOS-6.9-x86_64-LiveDVD

0_README.txt
CentOS-6.9-x86_64-LiveDVD.iso
README.txt
md5sums.txt
md5sums.txt.asc
sha1sums.txt
sha1sums.txt.asc
sha256sums.txt
sha256sums.txt.asc

aineko:centos_6_9_bootable_usb_stick stjohnpiano$ diff 0_README.txt CentOS-6.9-x86_64-LiveDVD/0_README.txt


aineko:centos_6_9_bootable_usb_stick stjohnpiano$ diff 0_README.txt CentOS-6.9-x86_64-LiveDVD/README.txt


aineko:centos_6_9_bootable_usb_stick stjohnpiano$ cd CentOS-6.9-x86_64-LiveDVD


aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ cat md5sums.txt

2e227fa14c8a9791293b6525289c7dad CentOS-6.9-x86_64-bin-DVD1.iso
e2152e0eeb082a92c0f925e7a99c872c CentOS-6.9-x86_64-bin-DVD2.iso
a807045c5f8037686f3375bd7b463753 CentOS-6.9-x86_64-LiveDVD.iso
af4a1640c0c6f348c6c41f1ea9e192a2 CentOS-6.9-x86_64-minimal.iso
cdab6b8142cb03e5f02102879d11ef44 CentOS-6.9-x86_64-netinstall.iso

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ cat md5sums.txt.asc

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

2e227fa14c8a9791293b6525289c7dad CentOS-6.9-x86_64-bin-DVD1.iso
e2152e0eeb082a92c0f925e7a99c872c CentOS-6.9-x86_64-bin-DVD2.iso
a807045c5f8037686f3375bd7b463753 CentOS-6.9-x86_64-LiveDVD.iso
af4a1640c0c6f348c6c41f1ea9e192a2 CentOS-6.9-x86_64-minimal.iso
cdab6b8142cb03e5f02102879d11ef44 CentOS-6.9-x86_64-netinstall.iso
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.14 (GNU/Linux)
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=ml4M
-----END PGP SIGNATURE-----

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ wget --version

GNU Wget 1.17.1 built on darwin10.8.0.

+digest -gpgme +https +ipv6 +iri +large-file -metalink +nls +ntlm
+opie -psl +ssl/gnutls

Wgetrc:
/opt/local/etc/wgetrc (system)
Locale:
/opt/local/share/locale
Compile:
/usr/bin/gcc-4.2 -DHAVE_CONFIG_H
-DSYSTEM_WGETRC="/opt/local/etc/wgetrc"
-DLOCALEDIR="/opt/local/share/locale" -I. -I../lib -I../lib
-I/opt/local/include -I/opt/local/include -I/opt/local/include
-I/opt/local/include/p11-kit-1 -I/opt/local/include
-DHAVE_LIBGNUTLS -I/opt/local/include -DNDEBUG -pipe -Os -arch
x86_64
Link:
/usr/bin/gcc-4.2 -I/opt/local/include -I/opt/local/include
-I/opt/local/include/p11-kit-1 -I/opt/local/include
-DHAVE_LIBGNUTLS -I/opt/local/include -DNDEBUG -pipe -Os -arch
x86_64 -L/opt/local/lib -Wl,-headerpad_max_install_names -arch
x86_64 -liconv -lintl -Wl,-framework -Wl,CoreFoundation
-L/opt/local/lib -lpcre -lnettle -L/opt/local/lib -lgnutls
-L/opt/local/lib -lz -lidn ftp-opie.o gnutls.o http-ntlm.o
../lib/libgnu.a

Copyright (C) 2015 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<http://www.gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Originally written by Hrvoje Niksic <hniksic@xemacs.org>.
Please send bug reports and questions to <bug-wget@gnu.org>.




Let's download a copy of the public key.

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ wget http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

--2017-11-13 00:21:12-- http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
Resolving mirror.centos.org (mirror.centos.org)... 88.150.173.218, 2a00:1650:1000::225:90ff:fe47:267a
Connecting to mirror.centos.org (mirror.centos.org)|88.150.173.218|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1706 (1.7K) [text/plain]
Saving to: 'RPM-GPG-KEY-CentOS-6'

RPM-GPG-KEY-CentOS- 100%[===================>] 1.67K --.-KB/s in 0s

2017-11-13 00:21:12 (50.8 MB/s) - 'RPM-GPG-KEY-CentOS-6' saved [1706/1706]

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ cat RPM-GPG-KEY-CentOS-6

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.5 (GNU/Linux)
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=jrWY
-----END PGP PUBLIC KEY BLOCK-----

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ gpg --quiet --with-fingerprint RPM-GPG-KEY-CentOS-6

pub 4096R/C105B9DE 2011-07-03 CentOS-6 Key (CentOS 6 Official Signing Key) <centos-6-key@centos.org>
Key fingerprint = C1DA C52D 1664 E8A4 386D BA43 0946 FCA2 C105 B9DE



On www.centos.org/keys, I find:

CentOS-6 Signing Key
pub 4096R/C105B9DE 2011-07-03 CentOS-6 Key (CentOS 6 Official Signing Key) <centos-6-key@centos.org>
Key fingerprint = C1DA C52D 1664 E8A4 386D BA43 0946 FCA2 C105 B9DE


[fingerprint of downloaded key]
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ s1="C1DA C52D 1664 E8A4 386D BA43 0946 FCA2 C105 B9DE"


[fingerprint shown on web page https://www.centos.org/keys]
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ s2="C1DA C52D 1664 E8A4 386D BA43 0946 FCA2 C105 B9DE"


Check that these fingerprints are identical.
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ [[ "$s1" = "$s2" ]] && echo equal || echo not-equal

equal



I'm going to use a temporary keyring to check the signatures.

Note: This means that the following commands will not affect the data stored within the gpg program (i.e. the program's "state"). If commands affect a program's state, this can make it harder to write scripts to automate stuff, because now a script might have to include behaviour to handle whatever is in the preserved state of the program.


aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ mkdir keyring_tmp


aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ gpg --no-default-keyring --keyring pubring.gpg --homedir keyring_tmp --import RPM-GPG-KEY-CentOS-6

gpg: WARNING: unsafe permissions on homedir `keyring_tmp'
gpg: keyring `keyring_tmp/secring.gpg' created
gpg: keyring `keyring_tmp/pubring.gpg' created
gpg: keyring_tmp/trustdb.gpg: trustdb created
gpg: key C105B9DE: public key "CentOS-6 Key (CentOS 6 Official Signing Key) <centos-6-key@centos.org>" imported
gpg: Total number processed: 1
gpg: imported: 1 (RSA: 1)

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ gpg --no-default-keyring --keyring pubring.gpg --homedir keyring_tmp --verify md5sums.txt.asc

gpg: WARNING: unsafe permissions on homedir `keyring_tmp'
gpg: Signature made Tue Apr 4 19:56:16 2017 GMT using RSA key ID C105B9DE
gpg: Good signature from "CentOS-6 Key (CentOS 6 Official Signing Key) <centos-6-key@centos.org>"
gpg: WARNING: This key is not certified with a trusted signature!
gpg: There is no indication that the signature belongs to the owner.
Primary key fingerprint: C1DA C52D 1664 E8A4 386D BA43 0946 FCA2 C105 B9DE
gpg: WARNING: not a detached signature; file 'md5sums.txt' was NOT verified!



Hm. Let's examine this warning: WARNING: unsafe permissions on homedir `keyring_tmp'.

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ ls -l

total 3952712
-rw-r--r-- 1 stjohnpiano staff 1706 Nov 13 00:00 0_README.txt
-rw-r--r-- 1 stjohnpiano staff 2023751680 Nov 13 00:01 CentOS-6.9-x86_64-LiveDVD.iso
-rw-r--r-- 1 stjohnpiano staff 1706 Nov 12 23:42 README.txt
-rw-r--r-- 1 stjohnpiano staff 1706 Jul 10 2011 RPM-GPG-KEY-CentOS-6
drwxr-xr-x 6 stjohnpiano staff 204 Nov 13 00:25 keyring_tmp
-rw-r--r-- 1 stjohnpiano staff 325 Nov 12 23:42 md5sums.txt
-rw-r--r-- 1 stjohnpiano staff 1208 Nov 12 23:42 md5sums.txt.asc
-rw-r--r-- 1 stjohnpiano staff 365 Nov 12 23:42 sha1sums.txt
-rw-r--r-- 1 stjohnpiano staff 1248 Nov 12 23:42 sha1sums.txt.asc
-rw-r--r-- 1 stjohnpiano staff 485 Nov 12 23:42 sha256sums.txt
-rw-r--r-- 1 stjohnpiano staff 1368 Nov 12 23:42 sha256sums.txt.asc


I think GPG is complaining about that other users are allowed to read stuff in keyring_tmp.

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ chmod 700 keyring_tmp/


aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ gpg --no-default-keyring --keyring pubring.gpg --homedir keyring_tmp --verify md5sums.txt.asc

gpg: Signature made Tue Apr 4 19:56:16 2017 GMT using RSA key ID C105B9DE
gpg: Good signature from "CentOS-6 Key (CentOS 6 Official Signing Key) <centos-6-key@centos.org>"
gpg: WARNING: This key is not certified with a trusted signature!
gpg: There is no indication that the signature belongs to the owner.
Primary key fingerprint: C1DA C52D 1664 E8A4 386D BA43 0946 FCA2 C105 B9DE
gpg: WARNING: not a detached signature; file 'md5sums.txt' was NOT verified!



Yup.

This warning:
gpg: WARNING: This key is not certified with a trusted signature!
is fine. I haven't given the CentOS-6 Key (CentOS 6 Official Signing Key) a trust rating (this would involve making changes to the state of the gpg program).

This warning:
gpg: WARNING: not a detached signature; file 'md5sums.txt' was NOT verified!
is also fine. md5sums.txt.asc is a clearsigned text file. It's not meant to verify md5sums.txt.


This line:
gpg: Good signature from "CentOS-6 Key (CentOS 6 Official Signing Key) <centos-6-key@centos.org>"
means that gpg thinks that the signature is valid.


Let's select the hash from md5sums.txt.asc corresponding to the CentOS-6.9-x86_64-LiveDVD.iso:
a807045c5f8037686f3375bd7b463753 CentOS-6.9-x86_64-LiveDVD.iso


Now hash the iso image file:

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ md5 CentOS-6.9-x86_64-LiveDVD.iso

(CentOS-6.9-x86_64-LiveDVD.iso) = a807045c5f8037686f3375bd7b463753


[from md5sums.txt.asc]
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ s1="a807045c5f8037686f3375bd7b463753"


[from running the md5 command]
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ s2="a807045c5f8037686f3375bd7b463753"


Check that the hash values are identical.
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ [[ "$s1" = "$s2" ]] && echo equal || echo not-equal

equal



The md5 hash result matches the md5 hash value in the clearsigned file.



Let's check the sha1 signature and value.

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ gpg --no-default-keyring --keyring pubring.gpg --homedir keyring_tmp --verify sha1sums.txt.asc

gpg: Signature made Tue Apr 4 19:56:18 2017 GMT using RSA key ID C105B9DE
gpg: Good signature from "CentOS-6 Key (CentOS 6 Official Signing Key) <centos-6-key@centos.org>"
gpg: WARNING: This key is not certified with a trusted signature!
gpg: There is no indication that the signature belongs to the owner.
Primary key fingerprint: C1DA C52D 1664 E8A4 386D BA43 0946 FCA2 C105 B9DE
gpg: WARNING: not a detached signature; file 'sha1sums.txt' was NOT verified!

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ cat sha1sums.txt.asc

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

09c68654986feee54dcc6cad72771b7fe4be9703 CentOS-6.9-x86_64-bin-DVD1.iso
1415937993b615956c8c4239544366e0674bf042 CentOS-6.9-x86_64-bin-DVD2.iso
21531d5d403bb9dbb3bd35efbf9fc6dff8c02bfd CentOS-6.9-x86_64-LiveDVD.iso
b23d4d996d2cb5b370120588d5ea18a9cfba7881 CentOS-6.9-x86_64-minimal.iso
32f9f74fd27ec1ff7cc4f39a80d0dae34d9ec18b CentOS-6.9-x86_64-netinstall.iso
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.14 (GNU/Linux)
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=jKV2
-----END PGP SIGNATURE-----



Select the line corresponding to the LiveDVD iso.
21531d5d403bb9dbb3bd35efbf9fc6dff8c02bfd CentOS-6.9-x86_64-LiveDVD.iso

Run the sha1 hash algorithm on the iso.
Note: The shasum command uses sha1 by default.
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ shasum CentOS-6.9-x86_64-LiveDVD.iso

21531d5d403bb9dbb3bd35efbf9fc6dff8c02bfd CentOS-6.9-x86_64-LiveDVD.iso


[from sha1sums.txt.asc]
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ s1="21531d5d403bb9dbb3bd35efbf9fc6dff8c02bfd"


[from running the shasum command]
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ s2="21531d5d403bb9dbb3bd35efbf9fc6dff8c02bfd"


Check that the hash values are identical.
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ [[ "$s1" = "$s2" ]] && echo equal || echo not-equal

equal



sha1 hash confirmed.


Last one: sha256 hash.


aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ gpg --no-default-keyring --keyring pubring.gpg --homedir keyring_tmp --verify sha256sums.txt.asc

gpg: Signature made Tue Apr 4 19:56:21 2017 GMT using RSA key ID C105B9DE
gpg: Good signature from "CentOS-6 Key (CentOS 6 Official Signing Key) <centos-6-key@centos.org>"
gpg: WARNING: This key is not certified with a trusted signature!
gpg: There is no indication that the signature belongs to the owner.
Primary key fingerprint: C1DA C52D 1664 E8A4 386D BA43 0946 FCA2 C105 B9DE
gpg: WARNING: not a detached signature; file 'sha256sums.txt' was NOT verified!

aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ cat sha256sums.txt.asc

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

d27cf37a40509c17ad70f37bc743f038c1feba00476fe6b69682aa424c399ea6 CentOS-6.9-x86_64-bin-DVD1.iso
631b8640460f46a8139a6a7cbbac5f3594d08c32945449b6bbd65234929ce7a4 CentOS-6.9-x86_64-bin-DVD2.iso
422af57b493b8af49d485885a730c5a1d955f803fac85aa51311c393168b9080 CentOS-6.9-x86_64-minimal.iso
6b2cbec908708476389b143841a8e73462506de0744bda8b4192d3655d5bb8d2 CentOS-6.9-x86_64-netinstall.iso
ae56f677786673ad476477ed2df84ce80cf5f9b90a44e25146e69ef3cfd02602 CentOS-6.9-x86_64-LiveDVD.iso
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.14 (GNU/Linux)
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=QFrh
-----END PGP SIGNATURE-----



Select the line corresponding to the LiveDVD iso.
ae56f677786673ad476477ed2df84ce80cf5f9b90a44e25146e69ef3cfd02602 CentOS-6.9-x86_64-LiveDVD.iso

Run the sha256 hash algorithm on the iso.
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ shasum -a 256 CentOS-6.9-x86_64-LiveDVD.iso

ae56f677786673ad476477ed2df84ce80cf5f9b90a44e25146e69ef3cfd02602 CentOS-6.9-x86_64-LiveDVD.iso


[from sha256sums.txt.asc]
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ s1="ae56f677786673ad476477ed2df84ce80cf5f9b90a44e25146e69ef3cfd02602"


[from running the shasum command]
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ s2="ae56f677786673ad476477ed2df84ce80cf5f9b90a44e25146e69ef3cfd02602"


Check that the hash values are identical.
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ [[ "$s1" = "$s2" ]] && echo equal || echo not-equal

equal



sha256 hash confirmed.



Next: Prepare the USB memory stick and write the LiveDVD iso image to it.

I have a Toshiba 16 GB stick.


Starting with CentOS 6.5, one can install from USB keys by simply transferring the desired ISO using dd.

For example, assuming your USB stick is seen as /dev/sdb (please double check what yours is, do not blindly assume /dev/sdb as you may overwrite something irretrievably):

dd if=CentOS-6.5-x86_64-bin-DVD1.iso of=/dev/sdb


You must write to the entire device and not a partition on it (so, /dev/sdb not /dev/sdb1)


Source:
wiki.centos.org/HowTos/InstallFromUSBkey


In notes from a previous project, I find this recipe for writing an image to an SD card:

- format the SD card as a single FAT32 partition. Partition scheme = Master Boot Record. On Mac, use Disk Utility to format the card.
- change to the directory containing the OS image (e.g. 2014-09-09-wheezy-raspbian.img)
- $ df -h
- plug in SD card writer with SD card already inserted.
- $ df -h
find the disk name that wasn't listed before (e.g. disk1s1)
- $ sudo diskutil unmount /dev/disk1s1
- get raw device name: delete partition name e.g. 's1' and add 'r' to the front. In this case: /dev/disk1s1 becomes /dev/rdisk1
WARNING: If you make a mistake in the next step you could wipe your operating system.
- $ sudo dd bs=1m if=2014-09-09-wheezy-raspbian.img of=/dev/rdisk1
This should take a few minutes.
- $ sudo diskutil eject /dev/disk1




WARNING: Perform your backups now in order to avoid catastrophic data loss from making a mistake when using Disk Utility or when running the dd command.



Insert memory stick. It mounts automatically.

Open Disk Utility (Version 11.5.2 (298.4)).

In Disk Utility, select the memory stick (it shows up as "15.52 GB TOSHIBA Trans...").

Click Erase tab.
- Format = MS-DOS (FAT)
- Name = CENTOS6_9_L
Click Erase. Click Erase on the "are you sure" pop-up window.

Click Partition tab. Under Volume Scheme, choose 1 Partition. Click Options to choose Master Boot Record partition scheme.
- Name = CENTOS6_9_L
- Format = MS-DOS (FAT)
- Size = 15.52
Click Apply. Click Partition on the "are you sure" pop-up window.

In Disk Utility, the options for partition scheme are:
1) GUID Partition Table
To use the disk to start up an Intel-based Mac, or to use the disk as a non-startup disk with any Mac with Mac OS X version 10.4 or later.
2) Apple Partition Map
To use the disk to start up a PowerPC-based Mac, or to use the disk as a non-startup disk with any Mac.
3) Master Boot Record
To use the disk to start up DOS and Windows computers, or to use with devices that require a DOS-compatible or Windows-compatible partition.

Eject CENTOS6_9_L disk (right-click icon on Desktop and choose Eject).

Quit Disk Utility.

Remove the CENTOS6_9_L stick.


aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ df -h

Filesystem Size Used Avail Capacity Mounted on
/dev/disk0s2 117Gi 104Gi 13Gi 89% /
devfs 109Ki 109Ki 0Bi 100% /dev
map -hosts 0Bi 0Bi 0Bi 100% /net
map auto_home 0Bi 0Bi 0Bi 100% /home
/dev/disk0s3 32Gi 14Gi 18Gi 45% /Volumes/Untitled



Re-insert the CENTOS6_9_L memory stick. It mounts automatically.


aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ df -h

Filesystem Size Used Avail Capacity Mounted on
/dev/disk0s2 117Gi 104Gi 13Gi 89% /
devfs 110Ki 110Ki 0Bi 100% /dev
map -hosts 0Bi 0Bi 0Bi 100% /net
map auto_home 0Bi 0Bi 0Bi 100% /home
/dev/disk0s3 32Gi 14Gi 18Gi 45% /Volumes/Untitled
/dev/disk1s1 14Gi 768Ki 14Gi 1% /Volumes/CENTOS6_9_L



Find the disk name that wasn't listed before: disk1s1

Unmount the disk.
aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ diskutil unmount /dev/disk1s1

Volume CENTOS6_9_L on disk1s1 unmounted


Get raw device name: delete partition name e.g. 's1' and add 'r' to the front. In this case: /dev/disk1s1 becomes /dev/rdisk1


WARNING: If you make a mistake in the next step you could wipe your operating system.



aineko:CentOS-6.9-x86_64-LiveDVD stjohnpiano$ sudo dd bs=1m if=CentOS-6.9-x86_64-LiveDVD.iso of=/dev/rdisk1

Password:
1930+0 records in
1930+0 records out
2023751680 bytes transferred in 433.717645 secs (4666058 bytes/sec)



433 seconds / (60 seconds / minute) ~= 7.2 minutes


Remove and re-insert the disk.

Disk is auto-mounted as CentOS-6.9-x86_6.

Eject disk.

Remove memory stick.



Insert memory stick into one of Kalkin's USB ports.

I get a Centos 6 splash screen and an "automatically booting in 10 seconds..." message.

During boot, there is a splash screen saying:

CentOS 6
Community ENTerprise Operating System


So that's evidently where Centos gets its name.

Then, after boot, there's a login screen. After a little while it automatically logs in. A desktop appears.

Clicked around a bit. Opened an Terminal instance.

[centoslive@livedvd ~]$ echo "hello world"

hello world



And there we are.