some question about installing Centos7

General support questions
Post Reply
wallent
Posts: 1
Joined: 2018/03/23 09:02:30

some question about installing Centos7

Post by wallent » 2018/03/23 09:15:33

Hi everyone,
i'm a linux newer. I just get the error "dev/root does no exist" when installing centos7. I googled for it and just changed the initrd=...hd:/dev/sdb4, but still failed.
I guess sdb4 not the right word for my usb device but i couldnot find the right one because there are more than 15 devices whose name is like sda/sda1..sda8/sdb/sdc and so on. I can only use cd /dev/ & ls to show ,does anyone know other command that could show details of devices so i can know which is i want.

thanks...

scottro
Forum Moderator
Posts: 2556
Joined: 2007/09/03 21:18:09
Location: NYC
Contact:

Re: some question about installing Centos7

Post by scottro » 2018/03/23 09:43:30

There's a saying, in Unix there's always more than one way to do things, with a corollary, someone will think your way is stupid, but at any rate one way is to unplug the device, plug it back in again and run

Code: Select all

dmesg|tail
It might show something like

Code: Select all

[379263.893984]  sdd: sdd1 sdd2 sdd3 sdd4
[379263.896702] sd 10:0:0:0: [sdd] Attached SCSI removable disk
Now I know that the USB I just plugged in is /dev/sdd.

fdisk -l (that's a lower case L, as in list) will show you all partitions with sizes in blocks. You can use a block to GB converter
http://www.unitconversion.org/data-stor ... rsion.html or just do df -h on each partition to figure out which is which (assuming you know the approximate size of your disk partitions).
New users should check the FAQ and Read Me First pages

User avatar
TrevorH
Site Admin
Posts: 33202
Joined: 2009/09/24 10:40:56
Location: Brighton, UK

Re: some question about installing Centos7

Post by TrevorH » 2018/03/23 10:04:16

That error means your installation media is corrupt. If you are using a USB stick then make sure you use one of the known-to-work utilities to create it from the iso image you downloaded. Many of the USB creation tools corrupt the CentOS iso as they try to be clever and rewrite it as they copy it. Information on USB key based installs can be found at http://wiki.centos.org/HowTos/InstallFromUSBkey

Also, make sure that the iso image you downloaded has the same sha256sum as the one listed in the CentOS 7.4 Release Notes https://wiki.centos.org/Manuals/ReleaseNotes/CentOS7
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

Post Reply