HP ILO VSP: CentOS 7/RHEL 7 Installation through Serial Console

Though it's feared or considered as outdated by some, command line tools (CLI) remain the right ones for many System Administration tasks. Among its countless advantages, there's tasks' automation through its Script-ability.

In this post, I'm willing to describe the Usage of HP ILO CLI utility for the Complete Installation of CentOS 7/RHEL 7 Distribution. Through this mean, one can complete a full System Installation from CLI. Such Installation are quite useful for many cases, like Remote Installation with low bandwidth, No need for  Advanced ILO license...

The Installation described below is a CentOS 7.1 System on Proliant G8 (using ILO4) and I'm leveraging on KickStart to automate its Install process. But, the same procedure can be easily adapted for other Linux Distributions.

Let's start by reviewing what is needed to complete that Installation:

1. Prerequisites:

• ILO Configured with Valid IP Addressing parameters and reachable through SSH

• Linux System (any distribution) with mkisofs installed

That Linux System will be used to build Custom CentOS/RHEL Image, in this case I'm using the System the same system to share the ISO mentioned below (Hostname: stivinstall; IP: 192.168.1.11)

• OS Distribution Media (ISO) available on the network and reachable from the ILO

As said above, I'm installing CentOS 7.1, so I shared the ISO on an http server (installed and configured on my Linux System) and checked that it's well available (http://192.168.1.11/mnt/CentOS-7-x86_64-DVD-1503-01-text.iso)

• (Optional) KickStart File for automated Installation

I'm leveraging on Kickstart to fully automate this Installation. But that is obviously optional. In this case, I made Kickstart file available on the same System where I hosted the OS ISO (http://192.168.1.11/dladc2-infpup01.ks)

2.  Modify CentOS 7 boot image to get output on Serial Console

By default, the boot ISO of RHEL 7/CentOS 7 will redirect its output to Graphical Console, so that needs to be modified to have Output directed to the Serial Console (VSP).

Mount the CentOS ISO on my elected Installation System (stivinstall)

[root@stivinstall ~]# mount -o loop /mnt/CentOS-7-x86_64-DVD-1503-01.iso /var/www/html/media_centos7u1/ mount: /dev/loop0 is write-protected, mounting read-only

The main directory we'll be modifying in this ISO is Isolinux, so Copy this directory under a temporarily writable directory.

[root@stivinstall ~]# cd /var/www/html/media_centos7u1/ [root@stivinstall media_centos7u1]# cp -a isolinux /tmp/ [root@stivinstall media_centos7u1]# cd /tmp/isolinux/

As we're aiming to have everything in Text (console) mode, we should first get rid of graphical feature, like image. So, in the boot.msg, remove the ^Xsplash.lss line and delete the boot.cat (will be re-created later)

[root@stivinstall isolinux]# cat boot.msg splash.lss - Press the 01<enter>07 key to begin the installation process. [root@stivinstall isolinux]# vim boot.msg [...] "boot.msg" 4L, 72C written [root@stivinstall isolinux]# cat boot.msg - Press the 01<enter>07 key to begin the installation process. [root@stivinstall isolinux]# rm boot.cat rm: remove regular file ‘boot.cat’? y

Now, the main and most important modifications are to add/edit two main configuration in the isolinux.cfg:

1. A new line with "serial 1 9600" which indicates to IsoLinux to redirect the output to the Serial Console
2. Append "console=ttyS1" to the Kernel Option (append initrd...). This is a kernel option that specifies what device to use as the primary console and its implies text as the Installation Mode.

Below, I've made use of diff between the modified and an unmodified isolinux.cfg to highlight that modifications. We can see that around Line 54 (this can obviously added as option in other place in the file), I added (the line starting with "#"is just a comment):

# Output to Serial Console ttyS1 - Stivesso
serial 1 9600


And for most of the append Kernel options (did this for Linux, Troubleshoot and Rescue Entries), I appended this at the end:
console=ttyS1

[root@stivinstall isolinux]# cp isolinux.cfg /tmp/ [root@stivinstall isolinux]# vim isolinux.cfg [...] "isolinux.cfg" 123L, 3135C written [root@stivinstall isolinux]# diff isolinux.cfg /tmp/isolinux.cfg 54,56d53 < # Output to Serial Console ttyS1 - Stivesso < serial 1 9600 < 67c64 < append initrd=initrd.img inst.stage2=hd:LABEL=CentOS\x207\x20x86_64 quiet console=ttyS1 --- > append initrd=initrd.img inst.stage2=hd:LABEL=CentOS\x207\x20x86_64 quiet 73c70 < append initrd=initrd.img inst.stage2=hd:LABEL=CentOS\x207\x20x86_64 rd.live.check quiet console=ttyS1 --- > append initrd=initrd.img inst.stage2=hd:LABEL=CentOS\x207\x20x86_64 rd.live.check quiet 99c96 < append initrd=initrd.img inst.stage2=hd:LABEL=CentOS\x207\x20x86_64 rescue quiet console=ttyS1 --- > append initrd=initrd.img inst.stage2=hd:LABEL=CentOS\x207\x20x86_64 rescue quiet

With that modification on isolinux.cfg completed, we can recreate the ISO. but first, we mount (with the --bind option) our modified directory under the isolinux directory of the mounted Image. Then, we can create the ISO using mkisofs.

Note that the volume ID (-V) of the ISO image must be the same as the inst.stage2= parameter in isolinux.cfg and replacing \x20 by a space (described in BZ#915563), Otherwise we'll be facing an Issue during the Installation and will be redirected to Dracut Emergency mode (... Warning: /dev/root does not exist, Entering emergency mode. Exit the shell to continue.)

[root@stivinstall isolinux]# mount --bind /tmp/isolinux /var/www/html/media_centos7u1/isolinux [root@stivinstall isolinux]# mkisofs -R -J -T -v -V "CentOS 7 x86_64" -no-emul-boot -boot-load-size 4 -boot-info-table -b isolinux/isolinux.bin -c isolinux/boot.cat -o /mnt/CentOS-7-x86_64-DVD-1503-01-text.iso /var/www/html/media_centos7u1 I: -input-charset not specified, using utf-8 (detected in locale settings) genisoimage 1.1.11 (Linux) [...] 99.78% done, estimate finish Sun Aug 30 09:34:35 2015 Total translation table size: 907346 Total rockridge attributes bytes: 400459 Total directory bytes: 606208 Path table size(bytes): 140 Done with: The File(s) Block(s) 2103975 Writing: Ending Padblock Start Block 2104510 Done with: Ending Padblock Block(s) 150 Max brk space used 3d2000 2104660 extents written (4110 MB) [root@stivinstall isolinux]# umount /var/www/html/media_centos7u1/isolinux

The following is just a way to check that the created ISO has the needed modification in isolinux.cfg.

[root@stivinstall isolinux]# mount -o loop /mnt/CentOS-7-x86_64-DVD-1503-01-text.iso /mnt/tst mount: /dev/loop1 is write-protected, mounting read-only [root@stivinstall isolinux]# grep -i console /mnt/tst/isolinux/isolinux.cfg # Output to Serial Console ttyS1 - Steve ESSO append initrd=initrd.img inst.stage2=hd:LABEL=CentOS\x207\x20x86_64 quiet console=ttyS1 append initrd=initrd.img inst.stage2=hd:LABEL=CentOS\x207\x20x86_64 rd.live.check quiet console=ttyS1 append initrd=initrd.img inst.stage2=hd:LABEL=CentOS\x207\x20x86_64 rescue quiet console=ttyS1 [root@stivinstall isolinux]# umount /mnt/tst

3.  Use ILO CLI to insert a virtual media

Once we've met the prerequisites listed above and created our modified ISO Image, we can go to the ILO (ssh) and insert the OS Distribution ISO in the ILO Virtual Media. This is done using the vm command, to see a full description of vm command options and syntax, one can use "help vm" as seen below

</>hpiLO-> help vm status=0 status_tag=COMMAND COMPLETED Sat Aug 29 07:53:09 2015 VM : Virtual media commands. Usage: vm <device> insert <path> -- Inserts an image CLP COMMAND: set /map1/oemhp_vm1/<device> oemhp_image=<path> vm <device> eject -- Ejects an image CLP COMMAND: set /map1/oemhp_vm1/<device> oemhp_image=none vm device get -- Gets the status of the virtual media CLP COMMAND: show /map1/oemhp_vm1/<device> vm <device> set <options> -- Sets the status of the virtual media CLP COMMAND: set /map1/oemhp_vm1/<device> <property=value> Command Options: Device is floppy or cdrom CLP device is floppydr or cddr Path is the url to the media image Access option is write_protect or write_allow Boot option is boot_always, boot_once, no_boot, connect or disconnect CLP properties are : oemhp_connect, oemhp_boot, oemhp_wp

Get the Status of the CDROM Virtual Media,

</>hpiLO-> vm cdrom get status=0 status_tag=COMMAND COMPLETED Sat Aug 29 07:53:31 2015 Image Connected = No Image URL = None VM Applet = No Boot Option = NO_BOOT Write Protect = No

Insert our OS Distribution ISO Image,

</>hpiLO-> vm cdrom insert http://192.168.1.11/mnt/CentOS-7-x86_64-DVD-1503-01-text.iso status=0 status_tag=COMMAND COMPLETED Sat Aug 29 07:54:25 2015 </>hpiLO-> vm cdrom get status=0 status_tag=COMMAND COMPLETED Sat Aug 29 07:54:28 2015 Image Connected = No Image URL = http://192.168.1.11/mnt/CentOS-7-x86_64-DVD-1503-01-text.iso VM Applet = No Boot Option = NO_BOOT Write Protect = Yes

Connect the Inserted OS Image,

</>hpiLO-> vm cdrom set connect status=0 status_tag=COMMAND COMPLETED Sat Aug 29 08:02:31 2015 </>hpiLO-> vm cdrom get status=0 status_tag=COMMAND COMPLETED Sat Aug 29 08:02:35 2015 Image Connected = Yes Image URL = http://192.168.1.11/mnt/CentOS-7-x86_64-DVD-1503-01-text.iso VM Applet = No Boot Option = BOOT_ALWAYS Write Protect = Yes

Set the system to boot on this image during the next reboot, for that we can either use boot_once to have it mounted and set as boot drive just during the next boot or boot_always to have it permanently mounted and set as boot drive.

</>hpiLO-> vm cdrom set boot_once status=0 status_tag=COMMAND COMPLETED Sat Aug 29 08:02:48 2015 </>hpiLO-> vm cdrom get status=0 status_tag=COMMAND COMPLETED Sat Aug 29 08:02:50 2015 Image Connected = Yes Image URL = http://192.168.1.11/mnt/CentOS-7-x86_64-DVD-1503-01-text.iso VM Applet = No Boot Option = BOOT_ONCE Write Protect = Yes

4.  OS Installation:

Now that we have the media Inserted, we can proceed to the OS Installation by powering on the Server (or resetting if it was already running) and getting to VSP (Virtual Serial Port) to complete OS Installation.
I strongly advise to have the ILO SSH Console opened in max window size to make sure that the console output fit the size of the SSH console.

</>hpiLO-> power on status=0 status_tag=COMMAND COMPLETED Sun Aug 30 08:43:47 2015 Server powering on ....... </>hpiLO-> vsp Virtual Serial Port Active: COM2 Starting virtual serial port. Press 'ESC (' to return to the CLI Session. ProLiant System BIOS - P71 (11/01/2014) Copyright 1982, 2014 Hewlett-Packard Development Company, L.P. 2 Processor(s) detected, 4 total cores enabled, Hyperthreading is enabled Proc 1: Intel(R) Xeon(R) CPU E5-2637 0 @ 3.00GHz Proc 2: Intel(R) Xeon(R) CPU E5-2637 0 @ 3.00GHz [...] ISOLINUX 4.05 0x54f93f16 Copyright (C) 1994-2011 H. Peter Anvin et al

We'll get to the following nice screen,

Press Up (to make sure it’s at “Install CentOS 7” entry) and Tab,

From here, you can either just press enter to proceed to an Interactive Install, or if you prefer to use KickStart (as I do :-) ), then just enter the appropriate options. In this case, I’m entering the following inst.ks=http://192.168.1.10/stix-1.ks ip=192.168.1.11::192.168.1.1:255.255.255.0::ens2f0:none (more details about RHEL7/CentOS7 Kickstart Install in this post)

My suggestion for entering the option, "don't copy-paste, better write..."

References:

http://blog.allot.fr/?p=85
https://rhinstaller.github.io/anaconda/boot-options.html (Anaconda Documentation)
http://hintshop.ludvig.co.nz/show/centos-text-cd/